Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon. Dozens or hundreds of integrated circuits are typically manufactured on a single semiconductor wafer. The individual dies are singulated by sawing the integrated circuits along a scribe line. The individual dies are then packaged separately, in multi-chip modules, or in other types of packaging, for example.
The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. These smaller electronic components such as integrated circuit dies may also require smaller and reliable packages that utilize less area than packages of the past, in some applications.
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
Other features and processes may also be included. For example, testing structures may be included to aid in the verification testing of the 3D packaging or 3DIC devices. The testing structures may include, for example, test pads formed in a redistribution layer or on a substrate that allows the testing of the 3D packaging or 3DIC, the use of probes and/or probe cards, and the like. The verification testing may be performed on intermediate structures as well as the final structure. Additionally, the structures and methods disclosed herein may be used in conjunction with testing methodologies that incorporate intermediate verification of known good dies to increase the yield and decrease costs.
Referring to
The through substrate vias 102b may be formed by forming recesses in the substrate 102a by, for example, etching, milling, laser techniques, a combination thereof, and/or the like. A thin barrier layer may be conformally deposited over the front side of the substrate 102a and in the openings, such as by chemical vapor deposition (CVD), atomic layer deposition (ALD), physical vapor deposition (PVD), thermal oxidation, a combination thereof, and/or the like. The barrier layer may include a nitride or an oxynitride, such as titanium nitride, titanium oxynitride, tantalum nitride, tantalum oxynitride, tungsten nitride, a combination thereof, and/or the like. A conductive material is deposited over the thin barrier layer and in the openings. The conductive material may be formed by an electro-chemical plating process, CVD, ALD, PVD, a combination thereof, and/or the like. Examples of conductive materials are copper, tungsten, aluminum, silver, gold, a combination thereof, and/or the like. Excess conductive material and barrier layer may be removed from the front side of the substrate 102a by, for example, chemical mechanical polishing (CMP). Thus, in some embodiments, the through substrate vias 102b may include a conductive material and a thin barrier layer between the conductive material and the substrate 102a. In some embodiments, the through substrate vias 102b may extend through one or more layers of the interconnect structure 102b and protrude into the substrate 102a. The through substrate vias 102b may be buried in the substrate 102a and the interconnect structure 102c of the semiconductor wafer 102. The through substrate vias 102b are not revealed from a back surface of the substrate 102a at this stage.
The interconnect structure 102c may include one or more dielectric layers (for example, one or more interlayer dielectric (ILD) layers, intermetal dielectric (IMD) layers, or the like) and interconnect wirings embedded in the one or more dielectric layers, and the interconnect wirings are electrically connected to the semiconductor devices (e.g., FinFETs) formed in the substrate 102a. The material of the one or more dielectric layers may include silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material. The interconnect wirings may include metallic wirings. For example, the interconnect wirings include copper wirings, copper pads, aluminum pads or combinations thereof.
The bonding structure 102d may include a bonding dielectric layer 102d1 and bonding conductors 102d2 embedded in the bonding dielectric layer 102d1. The material of the bonding dielectric layer 102d1 may be silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material, and the bonding conductors 102d2 may be conductive vias (e.g., copper vias), conductive pads (e.g., copper pads) or combinations thereof. The bonding structure 102d may be formed by depositing a dielectric material through a chemical vapor deposition (CVD) process (e.g., a plasma enhanced CVD process or other suitable process); patterning the dielectric material to form the bonding dielectric layer 102d1 including openings or through holes; and filling conductive material in the openings or through holes defined in the bonding dielectric layer 102d1 to form the bonding conductors 102d2 embedded in the bonding dielectric layer 102d1.
In some other embodiments, the semiconductor wafer 102 includes a semiconductor interposer, such as a silicon interposer or other suitable semiconductor interposer. In some alternative embodiments, the semiconductor wafer 102 includes a reconstructed wafer, and the reconstructed wafer may include semiconductor chips arranged in side-by-side manner and laterally encapsulated by an insulating encapsulant.
As illustrated in
Referring to
Each of the semiconductor dies 104 may include a substrate 104a (e.g., a semiconductor substrate), an interconnect structure 104b disposed on the substrate 104a, and a bonding structure 104c disposed on the interconnect structure 104b. The substrate 104a of each of the semiconductor dies 104 may include a crystalline silicon wafer. The substrate 104a may include various doped regions depending on design requirements (e.g., p-type substrate or n-type substrate). In some embodiments, the doped regions may be doped with p-type or n-type dopants. The doped regions may be doped with p-type dopants, such as boron or BF2; n-type dopants, such as phosphorus or arsenic; and/or combinations thereof. The doped regions may be configured for n-type Fin-type Field Effect Transistors (FinFETs) and/or p-type FinFETs. In some alternative embodiments, the substrate 104a may be made of some other suitable elemental semiconductor, such as diamond or germanium; a suitable compound semiconductor, such as gallium arsenide, silicon carbide, indium arsenide, or indium phosphide; or a suitable alloy semiconductor, such as silicon germanium carbide, gallium arsenic phosphide, or gallium indium phosphide.
The interconnect structure 104b may include one or more dielectric layers (for example, one or more interlayer dielectric (ILD) layers, intermetal dielectric (IMD) layers, or the like) and interconnect wirings embedded in the one or more dielectric layers, and the interconnect wirings are electrically connected to the semiconductor devices (e.g., FinFETs) formed in the substrate 104a. The material of the one or more dielectric layers may include silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material. The interconnect wirings may include metallic wirings. For example, the interconnect wirings include copper wirings, copper pads, aluminum pads or combinations thereof.
The bonding structure 104c may include a bonding dielectric layer 104cl and bonding conductors 104c2 embedded in the bonding dielectric layer 104c1. The material of the bonding dielectric layer 104cl may be silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material, and the bonding conductors 104c2 may be conductive vias (e.g., copper vias), conductive pads (e.g., copper pads) or combinations thereof. The bonding structure 104c may be formed by depositing a dielectric material through a chemical vapor deposition (CVD) process (e.g., a plasma enhanced CVD process or other suitable process); patterning the dielectric material to form the bonding dielectric layer 104cl including openings or through holes; and filling conductive material in the openings or through holes defined in the bonding dielectric layer 104cl to form the bonding conductors 104c2 embedded in the bonding dielectric layer 104c1.
Referring to
After installation of the edge support 120, a hard plate 130 and a buffer layer 140 carried by the hard plate 130 are provided over the semiconductor dies 104 as well as the semiconductor wafer 102 carried by the wafer chuck 110. The material of the hard plate 130 may be or include polyetheretherketone (PEEK), polyimide or other suitable plastic materials. The buffer layer 140 may be or include a release film or other flexible and buffer film. The buffer layer 140 is provided on a bottom surface 130a of the hard plate 130. After the buffer layer 140 is provided on the bottom surface 130a of the hard plate 130, the buffer layer 140 is provided between the hard plate 130 and the semiconductor dies 104. The buffer layer 140 may be applied or fed by a group of rollers 150 such that the buffer layer 140 can be fed onto the bottom surface 130a of the hard plate 130. The buffer layer 140 is capable of minimizing the Total Thickness Variation (TTV) issue of the semiconductor dies 104 during the subsequently performed Chip-to-Wafer (CoW) bonding process. The group of rollers 150 are capable of driving the movement of the buffer layer 140 such that different regions of the buffer layer 140 can be utilized to minimize the TTV issue of the semiconductor dies 104 during the subsequently performed Chip-to-Wafer (CoW) bonding process.
Referring to
After the buffer layer 140 is pressed onto the top surface of the edge support 120 and the surfaces (e.g., the back surfaces) of the semiconductor dies 104, an annealing process is performed such that the bonding structures 104c of the semiconductor dies 104 are in contact with and bonded to the bonding structure 102d of the semiconductor wafer 102. After performing the annealing process, a chip-to-wafer (CoW) bonding process of the semiconductor dies 104 and the semiconductor wafer 102 is accomplished.
After performing the above-mentioned chip-to-wafer (CoW) bonding process, a dielectric-to-dielectric bonding interface is formed between the bonding dielectric layer 104cl and the bonding dielectric layer 102d1, and metal-to-metal bonding interfaces are formed between the bonding conductors 104c2 and bonding conductors 102d2.
After the semiconductor dies 104 are bonded to the semiconductor wafer 102, a chip probing process may be performed to increase yields.
As illustrated in
Referring to
The through substrate vias 102b may be formed by forming recesses in the substrate 102a by, for example, etching, milling, laser techniques, a combination thereof, and/or the like. A thin barrier layer may be conformally deposited over the front side of the substrate 102a and in the openings, such as by chemical vapor deposition (CVD), atomic layer deposition (ALD), physical vapor deposition (PVD), thermal oxidation, a combination thereof, and/or the like. The barrier layer may include a nitride or an oxynitride, such as titanium nitride, titanium oxynitride, tantalum nitride, tantalum oxynitride, tungsten nitride, a combination thereof, and/or the like. A conductive material is deposited over the thin barrier layer and in the openings. The conductive material may be formed by an electro-chemical plating process, CVD, ALD, PVD, a combination thereof, and/or the like. Examples of conductive materials are copper, tungsten, aluminum, silver, gold, a combination thereof, and/or the like. Excess conductive material and barrier layer may be removed from the front side of the substrate 102a by, for example, chemical mechanical polishing (CMP). Thus, in some embodiments, the through substrate vias 102b may include a conductive material and a thin barrier layer between the conductive material and the substrate 102a. In some embodiments, the through substrate vias 102b may extend through one or more layers of the interconnect structure 102b and protrude into the substrate 102a. The through substrate vias 102b may be buried in the substrate 102a and the interconnect structure 102c of the semiconductor wafer 102. The through substrate vias 102b are not revealed from a back surface of the substrate 102a at this stage.
The interconnect structure 102c may include one or more dielectric layers (for example, one or more interlayer dielectric (ILD) layers, intermetal dielectric (IMD) layers, or the like) and interconnect wirings embedded in the one or more dielectric layers, and the interconnect wirings are electrically connected to the semiconductor devices (e.g., FinFETs) formed in the substrate 102a. The material of the one or more dielectric layers may include silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material. The interconnect wirings may include metallic wirings. For example, the interconnect wirings include copper wirings, copper pads, aluminum pads or combinations thereof.
The bonding structure 102d may include a bonding dielectric layer 102d1 and bonding conductors 102d2 embedded in the bonding dielectric layer 102d1. The material of the bonding dielectric layer 102d1 may be silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material, and the bonding conductors 102d2 may be conductive vias (e.g., copper vias), conductive pads (e.g., copper pads) or combinations thereof. The bonding structure 102d may be formed by depositing a dielectric material through a chemical vapor deposition (CVD) process (e.g., a plasma enhanced CVD process or other suitable process); patterning the dielectric material to form the bonding dielectric layer 102d1 including openings or through holes; and filling conductive material in the openings or through holes defined in the bonding dielectric layer 102d1 to form the bonding conductors 102d2 embedded in the bonding dielectric layer 102d1.
In some other embodiments, the semiconductor wafer 102 includes a semiconductor interposer, such as a silicon interposer or other suitable semiconductor interposer. In some alternative embodiments, the semiconductor wafer 102 includes a reconstructed wafer, and the reconstructed wafer may include semiconductor chips arranged in side-by-side manner and laterally encapsulated by an insulating encapsulant.
As illustrated in
Referring to
Each of the semiconductor dies 104 may include a substrate 104a (e.g., a semiconductor substrate), an interconnect structure 104b disposed on the substrate 104a, and a bonding structure 104c disposed on the interconnect structure 104b. The substrate 104a of each of the semiconductor dies 104 may include a crystalline silicon wafer. The substrate 104a may include various doped regions depending on design requirements (e.g., p-type substrate or n-type substrate). In some embodiments, the doped regions may be doped with p-type or n-type dopants. The doped regions may be doped with p-type dopants, such as boron or BF2; n-type dopants, such as phosphorus or arsenic; and/or combinations thereof. The doped regions may be configured for n-type Fin-type Field Effect Transistors (FinFETs) and/or p-type FinFETs. In some alternative embodiments, the substrate 104a may be made of some other suitable elemental semiconductor, such as diamond or germanium; a suitable compound semiconductor, such as gallium arsenide, silicon carbide, indium arsenide, or indium phosphide; or a suitable alloy semiconductor, such as silicon germanium carbide, gallium arsenic phosphide, or gallium indium phosphide.
The interconnect structure 104b may include one or more dielectric layers (for example, one or more interlayer dielectric (ILD) layers, intermetal dielectric (IMD) layers, or the like) and interconnect wirings embedded in the one or more dielectric layers, and the interconnect wirings are electrically connected to the semiconductor devices (e.g., FinFETs) formed in the substrate 104a. The material of the one or more dielectric layers may include silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material. The interconnect wirings may include metallic wirings. For example, the interconnect wirings include copper wirings, copper pads, aluminum pads or combinations thereof.
The bonding structure 104c may include a bonding dielectric layer 104cl and bonding conductors 104c2 embedded in the bonding dielectric layer 104c1. The material of the bonding dielectric layer 104cl may be silicon oxide (SiOx, where x>0), silicon nitride (SiNx, where x>0), silicon oxynitride (SiOxNy, where x>0 and y>0) or other suitable dielectric material, and the bonding conductors 104c2 may be conductive vias (e.g., copper vias), conductive pads (e.g., copper pads) or combinations thereof. The bonding structure 104c may be formed by depositing a dielectric material through a chemical vapor deposition (CVD) process (e.g., a plasma enhanced CVD process or other suitable process); patterning the dielectric material to form the bonding dielectric layer 104cl including openings or through holes; and filling conductive material in the openings or through holes defined in the bonding dielectric layer 104cl to form the bonding conductors 104c2 embedded in the bonding dielectric layer 104c1.
Referring to
In some embodiments, the edge support 220 is fastened on the bottom surface 230a of the hard plate 230 through, for example, screws or other suitable fastening elements such that the bottom surface 220a of the edge support 220 is vertically spaced apart from the semiconductor wafer 102. In some embodiments, the edge support 220 includes a ring-shaped support structure, and the edge support 220 is laterally as well as vertically spaced apart from the semiconductor dies 104. As illustrated in
The material of the hard plate 230 may be or include polyetheretherketone (PEEK), polyimide or other suitable plastic materials. The buffer layer 240 may be or include a release film or other flexible and buffer film. The buffer layer 240 is provided between the hard plate 230 and the semiconductor dies 104. At this stage, the buffer layer 240 is vertically spaced apart from the hard plate 230 and the semiconductor dies 104. The buffer layer 240 may be applied or fed by a group of rollers 250 such that the buffer layer 240 can be fed between the hard plate 230 and the semiconductor dies 104. The buffer layer 240 is capable of minimizing the Total Thickness Variation (TTV) issue of the semiconductor dies 104 during the subsequently performed Chip-to-Wafer (CoW) bonding process. The group of rollers 250 are capable of driving the movement of the buffer layer 240 such that different regions of the buffer layer 240 can be utilized to minimize the TTV issue of the semiconductor dies 104 during the subsequently performed Chip-to-Wafer (CoW) bonding process.
Referring to
After the buffer layer 240 is pressed onto the surfaces (e.g., the back surfaces) of the semiconductor dies 104, an annealing process is performed such that the bonding structures 104c of the semiconductor dies 104 are in contact with and bonded to the bonding structure 102d of the semiconductor wafer 102. After performing the annealing process, a chip-to-wafer (CoW) bonding process of the semiconductor dies 104 and the semiconductor wafer 102 is accomplished.
After performing the above-mentioned chip-to-wafer (CoW) bonding process, a dielectric-to-dielectric bonding interface is formed between the bonding dielectric layer 104cl and the bonding dielectric layer 102d1, and metal-to-metal bonding interfaces are formed between the bonding conductors 104c2 and bonding conductors 102d2.
After the semiconductor dies 104 are bonded to the semiconductor wafer 102, a chip probing process may be performed to increase yields.
Referring to
In the above-mentioned bonding tool 100 or 200, the bonding force is vertically applied onto the semiconductor dies 104 and there is no lateral bonding force applied to the semiconductor dies 104. Accordingly, non-bonding issue occurred at corner regions of the semiconductor dies 104 may be minimized, and yields of the Chip-on-Wafer (CoW) bonding process of the semiconductor dies 104 and the semiconductor wafer 102 may increase.
In accordance with some embodiments of the disclosure, a bonding tool for bonding semiconductor dies to a semiconductor wafer is provided. The bonding tool includes a wafer chuck, an edge support, a hard plate, and a buffer layer. The wafer chuck carries the semiconductor wafer and the semiconductor dies placed on the semiconductor wafer. The edge support is disposed on the wafer chuck, the semiconductor wafer and the semiconductor dies are laterally surrounded by the edge support, and a top surface of the edge support substantially levels with surfaces of the semiconductor dies. The hard plate is movably disposed over the semiconductor dies, the edge support and the wafer chuck. The buffer layer is disposed on a bottom surface of the hard plate, and the buffer layer is in contact with the top surface of the edge support and the semiconductor dies when the hard plate moves towards the edge support. In some embodiments, the wafer chuck includes a circular-shaped chuck, and the hard plate includes a circular-shaped hard plate. In some embodiments, the edge support includes a ring-shaped support structure, and the edge support is laterally spaced apart from the semiconductor wafer. In some embodiments, the wafer chuck includes a circular-shaped chuck, and a diameter of the ring-shaped support structure is smaller than a diameter of the circular-shaped chuck. In some embodiments, the hard plate includes a circular-shaped hard plate, and a diameter of the ring-shaped support structure is smaller than a diameter of the circular-shaped hard plate. In some embodiments, a material of the hard plate includes polyetheretherketone (PEEK) or polyimide. In some embodiments, the buffer layer includes a release film. In some embodiments, the bonding tool further includes a group of rollers for feeding the buffer layer onto the bottom surface of the hard plate.
In accordance with some alternative embodiments of the disclosure, a bonding tool for bonding semiconductor dies to a semiconductor wafer is provided. The bonding tool includes a hard plate, an edge support, and a buffer layer. The hard plate is movably disposed over the semiconductor dies. The edge support is disposed on a bottom surface of the hard plate, and the edge support includes a feed-in channel and a feed-out channel. The buffer layer penetrates through the feed-in channel and the feed-out channel such that the buffer layer is fed between the hard plate and the semiconductor dies, wherein the buffer layer is in contact with the semiconductor dies and the hard plate when the hard plate and the edge support move towards the semiconductor wafer. In some embodiments, the bonding tool further includes a wafer chuck, wherein the wafer chuck carries the semiconductor wafer and the semiconductor dies placed on the semiconductor wafer. In some embodiments, the wafer chuck includes a circular-shaped chuck, and the hard plate includes a circular-shaped hard plate. In some embodiments, the edge support is disposed between the hard plate and the semiconductor wafer. In some embodiments, the edge support is in contact with the semiconductor wafer when the hard plate and the edge support move towards the semiconductor wafer. In some embodiments, the edge support includes a ring-shaped support structure, and the hard plate includes a circular-shaped hard plate. In some embodiments, a diameter of the ring-shaped support structure is smaller than a diameter of the circular-shaped hard plate. In some embodiments, the bonding tool further includes a group of rollers for feeding the buffer layer between the hard plate and the semiconductor dies.
In accordance with some other embodiments of the disclosure, a bonding process is provided. Semiconductor dies are placed onto a semiconductor wafer. A buffer layer is provided between a hard plate and the semiconductor dies. The hard plate is moved towards the semiconductor dies to press the buffer layer onto the semiconductor dies, wherein after the buffer layer is pressed onto the semiconductor dies, a gap between the hard plate and the semiconductor wafer is maintained by an edge support disposed under the hard plate. After the buffer layer is pressed onto the semiconductor dies, an annealing process is performed to bond the semiconductor dies onto the semiconductor wafer. In some embodiments, the gap between the hard plate and the semiconductor wafer is maintained by the edge support disposed on the semiconductor wafer after the buffer layer is pressed onto the semiconductor dies. In some embodiments, the semiconductor wafer is carried by a wafer chuck. In some embodiments, the gap between the hard plate and the semiconductor wafer is maintained by the edge support disposed on the wafer chuck after the buffer layer is pressed onto the semiconductor dies.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.