Patent Application
20090165295
The present invention relates generally to the field of Electrochemical Fabrication and the associated formation of three-dimensional structures (e.g. microscale or mesoscale structures). In particular, it relates to electrochemical fabrication methods that incorporate dielectric materials into the layers of the structure being formed and/or that form structures on dielectric substrates.
A technique for forming three-dimensional structures (e.g. parts, components, devices, and the like) from a plurality of adhered layers was invented by Adam L. Cohen and is known as Electrochemical Fabrication. It is being commercially pursued by Microfabrica® Inc. (formerly MEMGen Corporation) of Van Nuys, Calif. under the name EFAB®. This technique was described in U.S. Pat. No. 6,027,630, issued on Feb. 22, 2000. This electrochemical deposition technique allows the selective deposition of a material using a unique masking technique that involves the use of a mask that includes patterned conformable material on a support structure that is independent of the substrate onto which plating will occur. When desiring to perform an electrodeposition using the mask, the conformable portion of the mask is brought into contact with a substrate while in the presence of a plating solution such that the contact of the conformable portion of the mask to the substrate inhibits deposition at selected locations. For convenience, these masks might be generically called conformable contact masks; the masking technique may be generically called a conformable contact mask plating process. More specifically, in the terminology of Microfabrica® Inc. (formerly MEMGen Corporation) of Burbank, Calif. such masks have come to be known as INSTANT MASKS™ and the process known as INSTANT MASKING™ or INSTANT MASK™ plating. Selective depositions using conformable contact mask plating may be used to form single layers of material or may be used to form multi-layer structures. The teachings of the '630 patent are hereby incorporated herein by reference as if set forth in full herein. Since the filing of the patent application that led to the above noted patent, various papers about conformable contact mask plating (i.e. INSTANT MASKING) and electrochemical fabrication have been published:
The disclosures of these nine publications are hereby incorporated herein by reference as if set forth in full herein.
The electrochemical deposition process may be carried out in a number of different ways as set forth in the above patent and publications. In one form, this process involves the execution of three separate operations during the formation of each layer of the structure that is to be formed:
After formation of the first layer, one or more additional layers may be formed adjacent to the immediately preceding layer and adhered to the smoothed surface of that preceding layer. These additional layers are formed by repeating the first through third operations one or more times wherein the formation of each subsequent layer treats the previously formed layers and the initial substrate as a new and thickening substrate.
Once the formation of all layers has been completed, at least a portion of at least one of the materials deposited is generally removed by an etching process to expose or release the three-dimensional structure that was intended to be formed.
The preferred method of performing the selective electrodeposition involved in the first operation is by conformable contact mask plating. In this type of plating, one or more conformable contact (CC) masks are first formed. The CC masks include a support structure onto which a patterned conformable dielectric material is adhered or formed. The conformable material for each mask is shaped in accordance with a particular cross-section of material to be plated. At least one CC mask is needed for each unique cross-sectional pattern that is to be plated.
The support for a CC mask is typically a plate-like structure formed of a metal that is to be selectively electroplated and from which material to be plated will be dissolved. In this typical approach, the support will act as an anode in an electroplating process. In an alternative approach, the support may instead be a porous or otherwise perforated material through which deposition material will pass during an electroplating operation on its way from a distal anode to a deposition surface. In either approach, it is possible for CC masks to share a common support, i.e. the patterns of conformable dielectric material for plating multiple layers of material may be located in different areas of a single support structure. When a single support structure contains multiple plating patterns, the entire structure is referred to as the CC mask while the individual plating masks may be referred to as “submasks”. In the present application such a distinction will be made only when relevant to a specific point being made.
In preparation for performing the selective deposition of the first operation, the conformable portion of the CC mask is placed in registration with and pressed against a selected portion of the substrate (or onto a previously formed layer or onto a previously deposited portion of a layer) on which deposition is to occur. The pressing together of the CC mask and substrate occur in such a way that all openings, in the conformable portions of the CC mask contain plating solution. The conformable material of the CC mask that contacts the substrate acts as a barrier to electrodeposition while the openings in the CC mask that are filled with electroplating solution act as pathways for transferring material from an anode (e.g. the CC mask support) to the non-contacted portions of the substrate (which act as a cathode during the plating operation) when an appropriate potential and/or current are supplied.
An example of a CC mask and CC mask plating are shown in
Another example of a CC mask and CC mask plating is shown in
Unlike through-mask plating, CC mask plating allows CC masks to be formed completely separate from the fabrication of the substrate on which plating is to occur (e.g. separate from a three-dimensional (3D) structure that is being formed). CC masks may be formed in a variety of ways, for example, a photolithographic process may be used. All masks can be generated simultaneously, prior to structure fabrication rather than during it. This separation makes possible a simple, low-cost, automated, self-contained, and internally-clean “desktop factory” that can be installed almost anywhere to fabricate 3D structures, leaving any required clean room processes, such as photolithography to be performed by service bureaus or the like.
An example of the electrochemical fabrication process discussed above is illustrated in
Various components of an exemplary manual electrochemical fabrication system 32 are shown in
The CC mask subsystem 36 shown in the lower portion of
The blanket deposition subsystem 38 is shown in the lower portion of
The planarization subsystem 40 is shown in the lower portion of
Another method for forming microstructures from electroplated metals (i.e. using electrochemical fabrication techniques) is taught in U.S. Pat. No. 5,190,637 to Henry Guckel, entitled “Formation of Microstructures by Multiple Level Deep X-ray Lithography with Sacrificial Metal layers”. This patent teaches the formation of metal structure utilizing mask exposures. A first layer of a primary metal is electroplated onto an exposed plating base to fill a void in a photoresist, the photoresist is then removed and a secondary metal is electroplated over the first layer and over the plating base. The exposed surface of the secondary metal is then machined down to a height which exposes the first metal to produce a flat uniform surface extending across the both the primary and secondary metals. Formation of a second layer may then begin by applying a photoresist layer over the first layer and then repeating the process used to produce the first layer. The process is then repeated until the entire structure is formed and the secondary metal is removed by etching. The photoresist is formed over the plating base or previous layer by casting and the voids in the photoresist are formed by exposure of the photoresist through a patterned mask via X-rays or UV radiation.
The '637 patent teaches the locating of a plating base onto a substrate in preparation for electroplating materials onto the substrate. The plating base is indicated as typically involving the use of a sputtered film of an adhesive metal, such as chromium or titanium, and then a sputtered film of the metal that is to be plated. It is also taught that the plating base may be applied over an initial sacrificial layer of material on the substrate so that the structure and substrate may be detached if desired. In such cases after formation of the structure, the plating base may be patterned and removed from around the structure and then the sacrificial layer under the plating base may be dissolved to free the structure. Substrate materials mentioned in the '637 patent include silicon, glass, metals, and silicon with protected processed semiconductor devices. A specific example of a plating base includes about 150 angstroms of titanium and about 300 angstroms of nickel, both of which are sputtered at a temperature of 160° C. In another example it is indicated that the plating base may consist of 150 angstroms of titanium and 150 angstroms of nickel where both are applied by sputtering.
The '630 patent further indicates that the electroplating methods and articles disclosed therein allow fabrication of devices from thin layers of materials such as, e.g., metals, polymers, ceramics, and semiconductor materials. It further indicates that although the electroplating embodiments described therein have been described with respect to the use of two metals, a variety of materials, e.g., polymers, ceramics and semiconductor materials, and any number of metals can be deposited either by the electroplating methods therein, or in separate processes that occur throughout the electroplating method. It indicates that a thin plating base can be deposited, e.g., by sputtering, over a deposit that is insufficiently conductive (e.g., an insulating layer) so as to enable subsequent electroplating. It also indicates that multiple support materials (i.e. sacrificial materials) can be included in the electroplated element allowing selective removal of the support materials.
Even though electrochemical fabrication as taught and practiced to date, has greatly enhanced the capabilities of microfabrication, and in particular added greatly to the number of metal layers that can be incorporated into a structure and to the speed and simplicity in which such structures can be made, and even to the incorporation of some dielectric materials, room for and a need for enhancing dielectric incorporation and/or building on dielectric substrates exists.
It is an object of some embodiments of the invention to provide enhanced electrochemical fabrication methods for forming three-dimensional structures on dielectric substrates and/or for incorporating dielectrics into the formation of individual layers.
Other objects and advantages of various embodiments of the invention will be apparent to those of skill in the art upon review of the teachings herein. The various embodiments of the invention, set forth explicitly herein or otherwise ascertained from the teachings herein, may address one or more objects alone or in combination, or alternatively may address some other object of the invention ascertained from the teachings herein. It is not necessarily intended that all objects be addressed by any single aspect of the invention even though that may be the case with regard to some aspects.
In a first aspect of the invention, a process for forming a multilayer three-dimensional structure on a dielectric substrate, comprising: (a) depositing a first adhesion layer onto the substrate and a first seed layer onto the first adhesion layer; (b) using a contact mask, selectively deposit and adhere a conductive structural material to a selected portion of the seed layer material; (c) removing only a portion of seed layer material and adhesion layer material that is not coated over by the structural material; (d) blanket depositing a second adhesion layer material and a second seed layer material over the substrate, exposed portion of the first seed layer material, and the structural material; (e) blanket deposit sacrificial material; (f) planarize the deposited materials to set the height of a first layer and to expose the structural material; (g) form additional layers of the structure; and (h) release the structural material from the sacrificial material and remove the second seed layer and the second adhesion layer to reveal the completed structure.
In a second aspect of the invention, a process for forming a multilayer three-dimensional structure wherein at least three materials are used in the formation of the structure, comprising: (a) forming and adhering a first layer of material to the substrate via at least one seed layer material and/or at least one adhesion layer material, wherein the first layer comprises at least one region of a structural material and at least one region of a sacrificial material; (b) forming a subsequent layer from a plurality of materials that are adhered to previously deposited materials and repeating formation of subsequent layers until the structure is formed from a plurality of adhered layers; wherein the at least one seed layer material and/or the at least one adhesion layer material separating at least a portion of the structural material of the first layer from the dielectric substrate is different from a seed layer material and/or an adhesion layer material that separates at least a portion of the sacrificial material of the first layer from the dielectric material of the substrate, wherein at least one of a structural material or at least one of a sacrificial material is selectively patterned using a contact mask.
Further aspects of the invention will be understood by those of skill in the art upon reviewing the teachings herein. Other aspects of the invention may involve apparatus that can be used in implementing one or more of the above method aspects of the invention. These other aspects of the invention may provide various combinations of the aspects, embodiments, and associated alternatives explicitly set forth herein as well as provide other configurations, structures, functional relationships, and processes that have not been specifically set forth above.
The various embodiments, alternatives, and techniques disclosed herein may form multi-layer structures using a single patterning technique on all layers or using different patterning techniques on different layers. For example, different types of patterning masks and masking techniques may be used or even techniques that perform direct selective depositions without the need for masking may be used. For example, the methods disclosed herein for incorporating dielectrics may be used in combination with conformable contact masks and/or non-conformable contact masks and masking operations on all, some, or even no layers. Proximity masks and masking operations (i.e. operations that use masks that at least partially selectively shield a substrate by their proximity to the substrate even if contact is not made) may be used and/or adhered masks and masking operations (masks and operations that use masks that are adhered to a substrate onto which selective deposition or etching is to occur as opposed to only being contacted to it) may be used.
The process of
From block 102 the process moves forward to block 104. Block 104 calls for the deposition of at least one second material which may again be of the conductive type or of the dielectric type. The second material may be deposited in a blanket manner or may be deposited in a selective manner.
Next the process moves forward to block 106 which calls for the optional planarization of the deposited materials. This planarization may occur in a variety of ways, for example, by lapping, by chemical mechanical planarization, and/or by a machining operation.
From block 106 the process moves forward to block 108 which calls for the repetition of operations 1 to 3 of blocks 102, 104 and 106 respectively. Blocks 102 and 104 may in addition to the depositing of material also involve the processing of the deposited materials to achieve desired properties. Such processing may involve the heat treatment of the deposited materials, chemical treatment of the deposited materials, back filling of the deposited materials with supplemental material, and the like.
From block 108 the process moves forward to block 110 which calls for the performance of any additional operations that are necessary to give the deposited layers desired attributes. Such processing may involve those noted above for operations 102-104.
From operation 110 the process moves forward to operation 112 which calls for the optional repeating of operations 1 thru 5 one or more times to increase the number of layers that form the multi layer structure. In other words the operations of block 110 and 112 together imply that attribute enhancing operations may not only occur at the completion of the layer formation process but may also occur after only partial formation of the plurality of layers making up the multilayer structure.
From block 112 the process moves forward to block 114 which calls for the performance of any additional post processing operations that are necessary. Such post processing operations may include removal of one or more of the first or second materials. Such post processing may additionally or alternatively include the separation of the formed multi-layer structure from the substrate on which it was produced.
The process of
From block 122 the process moves forward to block 124 which calls for the optional performance of any necessary operations to give the deposited materials their desired attributes. Such operations may be similar to those described previously in association with
Next the process moves forward to block 126 which calls for the obtaining of a deposit of at least one second material, where the second material is one of a sacrificial conductive material, a structural conductive material, a sacrificial dielectric material or a structural dielectric material. In many embodiments the second material is of a different type than the first material. From block 126 the process moves forward to block 128 which like block 124 calls for the optional performance of any necessary operations required to give the materials their desired attributes.
From block 128 the process moves forward to block 132 which calls for the optional planarization of the deposited materials. It should be understood that in some alternative embodiments the order of the optional operations of block 128 and 132 may be reversed and/or the optional operation of block 132 may occur both before and after the operations of block 128.
From block 132 the process moves forward to block 134 which calls for the deposition of at least one third material. In many embodiments the third material is of a different type then the first material or the second material. In such embodiments, for example, a structural dielectric material may be one of the first through third materials deposited, a structural conductive material may be another of the first through third materials deposited while a sacrificial conductive material may be another of the first though third materials deposited.
After block 134 the process moves forward to block 136 which calls for the optional performance of any necessary operations to give the materials their desired attributes in a manner analogous to that of blocks 124 and 128.
From block 136 the process moves forward to block 138 which calls for the optional planarization of the deposited materials. Like blocks 132 and 128 the order of operations called for by blocks 136 and 138 may be reversed or alternately repeated more then one time.
From block 138 the process moves forward to block 140 which calls for the repeated operations of blocks 1 through 8 one ore more times to build up a multi-layer structure. After which the process moves forward to block 142 which calls for the optional performance of any necessary operations to give the deposited materials their desired attributes.
After block 142 the process moves forward to block 144 which calls for the repetition of blocks 1-9 one ore more times to increase the number of layers that form the multi-layer structure.
From block 144 the process moves forward to block 146 which calls for the performance of any post processing operations that are necessary to complete formation of the multi-layer structure.
In some embodiments of the invention, electrophoretic processes may be used in the deposition of dielectric materials (e.g. microscale and nanoscale materials) and even in the deposition of conductive materials. In still other embodiments of the invention other processes may be used to deposit dielectric materials, for example, dielectric materials may deposited by spreading or flowing a curable material over a surface to receive the dielectric material. The surface may be of a patterned type with voids to receive the dielectric or it may be unpatterned where it is intended that the deposited material blanket coat the substrate (or previous layer of the structure). The coating material may then be caused to solidify, or allowed to solidify, in a blanket manner or in a patterned manner (e.g. by selective or blanket exposure to curing radiation or by exposure to heat, vacuum or simply time, to allow a solvent or the like to evaporate. The dielectric material so formed may be patterned in a desired configuration or it may undergo additional patterning operations.
The selective electrophoretic deposition of a material may involve contact, proximity, and/or adhered masks and masking operations. Electrophoretic coating involves suspended, charged particles that migrate under an electric field to an electrode to form a coating. A large variety of materials can be deposited this way including ceramics, polymers, phosphors, glass, and even metals. Deposition rates may be orders of magnitude higher than that for electroplating (e.g., ˜1 mm/min).
A first embodiment of the invention, based on the process of
A second embodiment of the invention, based on the process of
The process of
From block 152 the process moves forward to block 154 which calls for electrophoretic blanket deposition of a dielectric material which has individual particles coated with a conductive material and wherein the height of deposition is at least equal to the layer thickness LT+δ.
From block 154 the process moves forward to block 156 which calls for the planarization of the deposits to a thickness of LT+δ.
Next the process moves forward to block 158 which calls for the electroplating of a conductive sacrificial material over the electrophoretically deposited material to fill in at least the voids located near the surface of the electrophoretically deposited material.
Next the process moves forward to block 162 which calls for the planarization of the deposits to a thickness equal to that of LT. From block 162 the process moves forward to block 164 which calls for the repetition of operations 1-5 of blocks 152-162 respectively so that a multi-layer structure is formed.
Next the process moves forward to block 166 which calls for the release of the structural conductive material and the dielectric material from the sacrificial conductive material which is located within the voids of the dielectric material (the electrophoretically deposited material).
Next the process moves forward to block 168 which optionally calls for the performance of any additionally desired post processing operations. For example, such operations may include the back filling of the porous dielectric material with a liquid dielectric that can be cured. Another such post processing operation might include the subjection of the particles of the dielectric to an operation that enhances the adhesion of the particles to one another.
The Process of
After the deposition of block 172 the process optionally moves forward to block 174 which calls for the planarization of the deposit to a thickness of LT+δ.
Next the process moves forward to the selective electrophoretic deposition of particles of a dielectric material that are coated with a conductive material. The selective deposition occurs via a contact or adhered type mask and the height of deposition is preferably at least LT+δ.
Next the process moves forward to block 178 which optionally calls for the planarization of the deposits to a thickness of LT+δ. In alternative embodiments that include both a planarization operation 174 and a planarization operation 178 the planarization operation 174 may be at a height some what greater then LT+δ and the associated deposition of block 172 may have a somewhat thicker minimum height.
From block 178 the process moves forward to block 172 which calls for the electroplating of a sacrificial material over both the electrophoretically deposited material and over exposed portions of the substrate (or previously formed layer). The sacrificial material may also be deposited over the structural conductive material deposited in association with block 172.
After completion of the operations of block 182 the process moves forward to block 184 which calls for the polarization of the deposits to a thickness equal to the layer thickness LT.
Next the process moves forward to block 186 which calls for the repetition of operations 1 through 6 associated with blocks 172-184 respectively, one or more times to build up a multi-layer structure. It will be understood that in alternative embodiments to this embodiment as well as to the other embodiments disclosed in this application instead of a repetition of operations used to form one layer of the structure, alternative formation operations may be used to form other layers of the structure.
From block 186 the process moves forward to block 188 which calls for the release of the structural conductive material and the dielectric material from the sacrificial conductive material.
Next the process moves forward to block 180 which calls optionally for the performance of any additionally desired post processing operations. It will be understood by those of skill in the art that in alternative embodiments the order of operations of block 188 and 190 may be reversed.
The process of
From block 192 the process moves forward to block 194 which optionally calls for the planarization of the material deposited in association with block 192.
From block 194 the process moves forward to block 196 which calls for the use of a mask of the contact or adhered type in the electroplating of a conductive sacrificial material over the electrophoretically deposited material and over the exposed portions of the substrate or previously formed layer that are to receive the sacrificial conductive material.
From block 196 the process moves forward to block 198 which optionally calls for the planarization of deposits to a thickness equal to or greater than the layer thickness LT plus an incremental amount δ. It will be understood by those of skill in the art that in alternative embodiments where a planarization operation of block 198 and a planarization operation of block 194 are to be performed, it may be desirable to perform the planarization operation of block 194 at a height somewhat above that of height of planarization of block 198. Similarly the height of deposition associated with block 192 may be set at a minimum that is greater than LT+δ.
From block 198 the process moves forward to block 200 which calls for the deposition of a conductive structural material having a height at least as great as LT. After the deposition of block 200 the process moves forward to block 202 which calls for the planarization of the deposit to a height of LT. The processes of blocks 204, 206 and 208 are similar to those called for by blocks 186, 188 and 190 respectively of
The process of
From block 212 the process moves forward to block 214 which calls for the optional planarization of the deposit made in association with block 212. From block 214 the process moves forward to block 216 which calls for selective electrophoretic deposition of particles of a dielectric material that are coated with a conductive material. The height of deposition is preferably at least equal to the layer thickness plus an incremental amount δ.
From block 216 the process moves forward to block 218 which calls for the optional planarization of the deposits to a thickness of LT+δ. As noted previously if the optional planarization processes of block 214 and 218 are both to be used the planarization height associated with block 214 may be somewhat greater than the amount LT+δ indicated in the figure.
From block 218 the process moves forward to block 220 which calls for the electroplating of a sacrificial material to fill at least the surface of the voids (i.e. pores) in the electrophoretically deposited material. The mask used for the selective deposition of block 220 may be the same mask used for the electrophoretic deposition of block 216 or alternatively it may be a different mask.
From block 220 the process moves forward to block 222 which optionally calls for the planarization of the deposits to a thickness of the LT+δ. It will be understood by those of skill in the art that in alternative embodiments where the planarization of block 222 is to be used along with one or both of the planarization operations of block 214 and 218 it may be desirable to set the level of planarization in block 218 and/or in block 214 to a height greater then LT+δ.
From block 222 the process moves forward to block 224 which calls for the deposition of a conductive structural material to a height of at least LT.
Block 226 then calls for the planarization of the deposited material to a thickness of the layer thickness, LT. The operations of blocks 228, 230 and 232 are analogous to those of blocks 186, 188 and 190 respectively.
The process of
From block 244 the process moves forward to block 246 which calls for the optional planarization of the deposits to a height equal to LT+δ.
From block 246 the process moves forward to block 248 which calls for the selective etching into the sacrificial material using a mask of the contact or adhered type such that a pattern corresponding to the locations where an electrophoretically deposited material is to exist.
From block 248 the process moves forward to block 250 which calls for the electrophoretic deposition of a dielectric material which includes particles that are covered with a conductive material. The height of deposition is preferably no less than LT+δ.
From block 250 the process moves forward to block 252 which calls for the blanket electrodeposition of a conductive sacrificial material over the previously deposited materials and particularly for the purpose of filling in the voids in the surface of the electrophoretically deposited material.
From block 252 the process moves forward to block 254 which calls for the planarization of the deposits to a thickness equal to LT. The operations of block 256, 258 and 260 are analogous to those of blocks 186, 188 and 190 respectively of
Those of skill in the art will understand that various embodiments, others than those of
In some embodiments, insulating particles may remain non-bonded while in other embodiments they may be bonded together. In some embodiments, air or gas pockets may remain between individual particles while in other embodiments, those pockets may be decreased in size or even eliminated by either compaction of the powder particles or by backfilling into the voids with a secondary solidifiable, non-conductive material. Such binding and/or compaction or densification may occur by application of heat, application of pressure, and/or a combination of heat and pressure to melt and bind or to sinter the particles together. In other embodiments back filling with a flowable fluid-like material may occur to cause binding or densification. For example, a reactive gas may be flow through the particles to initiate a chemical reaction that causes binding. A flowable liquid may be injected or otherwise made to fill, or at least partially occupy, the voids in between the particles after which the flowable liquid may be made to solidify by cooling (i.e. transition from a melted state to a solid state) by heating (e.g. to initiate a thermal polymerization process or to cause evaporation of a solvent), by exposure to selected radiation to cause a selective chemical reaction (e.g. polymerization), or the like. The operations that bind the particles together may occur on a layer-by-layer basis, after formation of a number of layers, or as a post processing operation.
In some other embodiments of the present invention, a lattice of conductive sacrificial material and dielectric structural material is formed along with conductive elements of the structure. The conductive material of the lattice is formed to avoid need for a seed layer over regions of dielectric material. The spacing of the sacrificial conductive elements are such that relative small gaps of dielectric material exist which can be readily bridged by a mushrooming of depositions (i.e. a spreading of the depositions over non-conductive material in the plane of the substrate as deposition height grows). The lattice preferably, provides a connection between all of the conductive sacrificial elements all the sacrificial material may be accessed and removed after the structure is formed and so that conductive paths exist so that each conductive element found on a layer may act as an initiation point for electrodeposition operations and for the spreading out of the depositions. Of course in alternative embodiments it may not be necessary for all sacrificial material to be interconnected in this manner.
Such structures may, for example, take the form of that shown in
After all layers are deposited, the sacrificial metal lattice may be etched to remove the metal lattice, leaving the dielectric lattice filled with air (e.g., for a low-K application). Or, if desired, the lattice can be infiltrated with the same or a different dielectric.
In some lattice based embodiments, the lattice need not take on a rectangular box-like structure as shown in
The process of
From block 332 the process moves forward to block 334 which calls for the blanket deposition of a conductive sacrificial material to regions of the substrate or previously formed layer not covered by the conductive structural material laid down during operation 332. The height of deposition is preferably at least equal to LT+δ.
From block 334 the process moves forward to block 336 which calls for the optional planarization of the deposits to a thickness of LT+δ.
From block 336 the process moves forward to block 338 which calls for the using of a mask of either the contact or adhered type for the selective etching into the sacrificial conductive material so as to form a pattern of voids corresponding to the locations where dielectric material is to be located.
After operation 338 is completed the process moves forward to block 340 which calls for the deposition of the dielectric material into at least the voids formed in the sacrificial material and to a height of at least the layer thickness plus an incremental amount. The deposition of dielectric material into the voids may also result in the deposition of dielectric material above the previously deposited materials. The deposition of the dielectric material may occur in a number of different ways. For example, the deposition may occur by electrophoretic means. As another example it may occur by dipping the structure into a desired liquid dielectric so as to overfill the voids and then spinning or wiping excess liquid from the surface of the structure and thereafter wiping or spinning the excess material away. Alternatively the liquid dielectric may be applied and hardened without removing any excess material and allowing a subsequent planarization operation to remove the excess material.
In still other alternatives the dielectric material may be applied by spraying, by sputtering, by stamping, and/or by ink jet dispensing. The deposited dielectric material may, for example, be of a ceramic type, thermal polymer type, thermoset polymer type, or photocurable polymer type. Still other types of dielectrics and deposition techniques will be understood by those of skill in the art upon review of the teachings herein.
After completion of the operation of block 340 the process moves forward to block 342 which calls for the planarization of the deposited materials to a thickness equal to that of the layer thickness. The repeating, releasing and optional post processing operations of blocks 344, 346 and 348 are similar to those discussed herein previously with regard to blocks 186, 188 and 190 of
The process of
Next the process of
After the deposition of block 354 the process continues through blocks 336, 340, 342, 344, 346 and 348 in the same manner as was previously described with regard to
In alternative embodiments the voids may be filled in with a temporary material so that planarization may occur with reduced risk of edge damage to portions of the deposited materials. Where, after the planarization operation is completed, the temporary material would be removed in any appropriate manner (e.g. by selective etching, development, melting, ablation with or without assistance of vacuum techniques or spraying or the like).
Those of skill in the art will understand that, modified embodiments for working with dielectric and sacrificial material grids are possible. It will be understood that different orders of deposition are possible, other orders of etching and filling are possible, working with additional materials of the conductive sacrificial or structural types are possible and working with dielectric sacrificial materials and/or additional dielectric structural materials is possible.
An eleventh embodiment of the invention provides a method for forming a multilayer structure on a dielectric substrate wherein the structure once formed will include a contact or bonding pad formed from a material forming a transition layer of a seed layer initially applied to the substrate. The process forms a multilayer structure on a dielectric substrate using a conductive structural material, a conductive sacrificial material, use of a first seed layer material combination, and use of a second seed layer material combination. The process includes the following operations:
A twelfth embodiment of the invention provides a method for incorporating both a dielectric and an externally fabricated device or structure (i.e. a non-electrochemically fabricated structure) into an electrochemical fabrication process.
After removal of sacrificial metal, optional infiltration of the dielectric lattice is possible. In some embodiments, infiltration may occur via capillary forces drawing a curable liquid dielectric into the pores of the lattice. Additionally, and/or in other embodiments, infiltration may be performed in vacuum.
Some embodiments may employ mask based selective etching operations in conjunction with blanket deposition operations. Some embodiments may form structures on a layer-by-layer base but deviate from a strict planar layer on planar layer build up process in favor of a process that interlacing material between the layers. Such alternating build processes are disclosed in U.S. application Ser. No. 10/434,519, filed on May 7, 2003, entitled Methods of and Apparatus for Electrochemically Fabricating Structures Via Interlaced Layers or Via Selective Etching and Filling of Voids which is herein incorporated by reference as if set forth in full.
Some embodiments may employ diffusion bonding or the like to enhance adhesion between successive layers of material. Various teachings concerning the use of diffusion bonding in electrochemical fabrication process is set forth in U.S. patent application Ser. No. 60/534,204, filed Dec. 31, 2003 by Cohen et al. which is entitled “Method for Fabricating Three-Dimensional Structures Including Surface Treatment of a First Material in Preparation for Deposition of a Second Material” and which is hereby incorporated herein by reference as if set forth in full.
Further teachings about planarizing layers and setting layers thicknesses and the like are set forth in the following US Patent Applications which were filed on Dec. 31, 2003: (1) U.S. patent application Ser. No. 60/534,159 by Cohen et al. and which is entitled “Electrochemical Fabrication Methods for Producing Multilayer Structures Including the use of Diamond Machining in the Planarization of Deposits of Material” and (2) U.S. patent application Ser. No. 60/534,183 by Cohen et al. and which is entitled “Method and Apparatus for Maintaining Parallelism of Layers and/or Achieving Desired Thicknesses of Layers During the Electrochemical Fabrication of Structures”. Still further teachings are found in concurrently U.S. patent application Ser. No. 11/029,220 (Docket No. P-US132-A-MF), filed Jan. 3, 2005 by Cohen et al. and which is entitled “Method and Apparatus for Maintaining Parallelism of Layers and/or Achieving Desired Thicknesses of Layers During the Electrochemical Fabrication of Structures”. These patent filings are each hereby incorporated herein by reference as if set forth in full herein.
Additional teachings concerning the formation of structures on dielectric substrates and/or the formation of structures that incorporate dielectric materials into the formation process and possibility into the final structures as formed are set forth in a number of patent applications: (1) U.S. patent application Ser. No. 60/534,184, by Cohen, which as filed on Dec. 31, 2003, and which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials and/or Using Dielectric Substrates”; (2) U.S. patent application Ser. No. 60/533,932, by Cohen, which was filed on Dec. 31, 2003, and which is entitled “Electrochemical Fabrication Methods Using Dielectric Substrates”; (3) U.S. patent application Ser. No. 60/534,157, by Lockard et al., which was filed on Dec. 31, 2004, and which is entitled “Electrochemical Fabrication Methods Incorporating Dielectric Materials”; (4) U.S. patent application Ser. No. 60/574,733, by Lockard et al., which was filed on May 26, 2004, and which is entitled “Methods for Electrochemically Fabricating Structures Using Adhered Masks, Incorporating Dielectric Sheets, and/or Seed Layers that are Partially Removed Via Planarization”; and U.S. patent application Ser. No. 60/533,895, by Lembrikov et al., which was filed on Dec. 31, 2003, and which is entitled “Electrochemical Fabrication Method for Producing Multi-layer Three-Dimensional Structures on a Porous Dielectric”. These patent filings are each hereby incorporated herein by reference as if set forth in full herein.
Various other embodiments of the present invention exist. Some of these embodiments may be based on a combination of the teachings herein with various teachings incorporated herein by reference. Some embodiments may not use any blanket deposition process and/or they may not use a planarization process. Some embodiments may involve the selective deposition of a plurality of different materials on a single layer or on different layers. Some embodiments may use selective deposition processes or blanket deposition processes on some layers that are not electrodeposition processes. Some embodiments may use nickel as a structural material while other embodiments may use different materials. Some embodiments may use copper as the structural material with or without a sacrificial material. Some embodiments may remove a sacrificial material while other embodiments may not. In some embodiments the anode (used during electrodeposition) may be different from a conformable contact mask support and the support may be a porous structure or other perforated structure. Some embodiments may use multiple conformable contact masks with different patterns so as to deposit different selective patterns of material on different layers and/or on different portions of a single layer.
Many other alternative embodiments will be apparent to those of skill in the art upon reviewing the teachings herein. Further embodiments may be formed from a combination of the various teachings explicitly set forth in the body of this application. Even further embodiments may be formed by combining the teachings set forth explicitly herein with teachings set forth in the various applications and patents referenced herein, each of which is incorporated herein by reference.
In view of the teachings herein, many further embodiments, alternatives in design and uses of the instant invention will be apparent to those of skill in the art. As such, it is not intended that the invention be limited to the particular illustrative embodiments, alternatives, and uses described above but instead that it be solely limited by the claims presented hereafter.
This application is continuation of U.S. patent application Ser. No. 11/029,181 (Microfabrica Docket No. P-US126-A-SC), filed Jan. 3, 2005, which in turn claims benefit of U.S. Provisional Application No. 60/533,890, filed Dec. 31, 2003 and is a continuation-in-part of U.S. patent application Ser. No. 10/309,521 (Docket No. P-US044-A-MG), filed Dec. 3, 2002. The 10/309,521 application claims benefit of U.S. Provisional Patent Application Nos.: 60/338,638 filed on Dec. 3, 2001; 60/340,372 filed on Dec. 6, 2001; 60/379,133 filed on May 7, 2002; 60/379,182 filed on May 7, 2002; 60/379,184 filed on May 7, 2002; 60/415,374 filed on Oct. 1, 2002; 60/379,130 filed on May 7, 2002 and 60/392,531 filed on Jun. 27, 2002. Each of these applications is hereby incorporated herein by reference as if set forth in full.
A portion of the inventions disclosed and potentially claimed herein were made with Government support under Grant Numbers DABT63-97-C-0051 and DABT63-99-C-0042 awarded by DARPA. The Government has certain rights. Not all inventions disclosed herein were developed or conceived with government funding and it is not intended that the government attain rights in such inventions.
| Number | Date | Country | |
|---|---|---|---|
| 60533890 | Dec 2003 | US | |
| 60338638 | Dec 2001 | US | |
| 60340372 | Dec 2001 | US | |
| 60379133 | May 2002 | US | |
| 60379182 | May 2002 | US | |
| 60379184 | May 2002 | US | |
| 60415374 | Oct 2002 | US | |
| 60379130 | May 2002 | US | |
| 60392531 | Jun 2002 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11029181 | Jan 2005 | US |
| Child | 12233142 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10309521 | Dec 2002 | US |
| Child | 11029181 | US |
