This Utility Patent Application claims priority to German Patent Application No. DE 10 2007 015 283.5 filed on Mar. 29, 2007, which is incorporated herein by reference.
Aspects relate to a test device for semiconductor devices and to a pertinent semiconductor device and a pertinent wafer, to a system with a test device and with a semiconductor device or wafer, and to a method for testing semiconductor devices.
Semiconductor devices, e.g., integrated (e.g., analog or digital and/or mixed-signal) circuits, semiconductor memory devices such as, for instance, functional memory devices (PLAs, PALs, etc.) and table memory devices (e.g., ROMs and RAMs, for example, SRAMs and DRAMs), etc. are subject to comprehensive tests, e.g., in the semi-finished and/or finished state, at a plurality of test stations.
For testing the semiconductor devices, a semiconductor device test device may be present at the respective test station which generates the test signals required for testing the semiconductor devices.
For instance, at a first test station, the signals required for testing the semiconductor devices that are still available on the wafer may, for instance, be generated by a test device that is connected with a semiconductor device test card (“probe card”), and may be input in the respective contact fields of the semiconductor devices using needle-shaped connections (“contact needles”) provided at the test card.
The signals output by the semiconductor devices at contact fields in reaction to the input test signals are tapped by corresponding, needle-shaped connections (“contact needles” or “test needles”) of the probe card, and (e.g., via a signal line that connects the probe card with the test device) transmitted to the test device where an evaluation of the signals can take place.
After the sawing apart of the wafer, the devices, that are then available individually, can each be loaded individually in carriers (i.e. a package) and be transported further to a further test station.
At the further test station, the carriers are inserted in adapters or sockets, that are connected with a (further) test device, and then the device that is available in the respective carrier is subject to (further) test methods.
For testing the semiconductor devices available in the carriers, the test signals output by the test device are transmitted to the contact fields of the respective semiconductor device via the adapter and the carrier (or connections of the carrier, respectively).
The signals output by the semiconductor devices at contact fields in reaction to the input test signals are tapped by carrier connections and transmitted, via the adapter (and a signal line connecting the adapter with the test device), to the test device where an evaluation of the signals can take place.
Similarly, the semiconductor devices may, for instance, also be tested after their final incorporation in device packages (e.g., plug or surface-mountable packages), and/or after the incorporation of the packages, provided with semiconductor devices, in corresponding, electronic modules, etc.
Probe cards have to be manufactured with very high precision, so that they properly contact all the contact fields or pads during the contacting of the wafer. This has to be ensured under any usual specified conditions such as, for instance, for the entire active face of the probe card, and under the specified temperatures. This demands a very high manufacturing accuracy which partly also has an influence on the design of the chips or semiconductor devices. In addition, a high technical effort in the wafer prober is required for equipping the probe cards. Errors will result in a lower yield, e.g., by using contact field edge damages, contact problems, and damage to the contact fields by too deep penetration of the needle tip. For these and other reasons, there exists a need for the present invention.
The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise.
One aspect provides a possibility for the simplified contacting of contact fields of semiconductor devices by appropriate test devices, which is, moreover, sufficiently precise, reliable, and gentle.
One embodiment includes a test device for semiconductor devices, for example, a probe card, including at least one contact test body for contacting a semiconductor device, wherein the probe card includes self-alignment device and/or a penetration restriction device, or parts thereof.
In one embodiment, at least one contact test body is a test needle.
In one embodiment, a contact test body is designed sufficiently elastically and/or suspended flexibly, e.g., by using a cardan suspension, a spring element, or an elastic, in one embodiment soft elastic, suspension.
In one embodiment, the contact test body includes at its tip at least one guide edge that is, in a particularly favorable manner, arranged at the outer edge region of the tip. In one embodiment, the guide edge is designed to be annularly circumferential, in one embodiment in the shape of a truncated cone.
In one embodiment, the contact test body includes at least one magnetic element, in one embodiment a permanent magnet and/or a switchable electromagnet. Then, the contact test body is suspended flexibly by using a cardan suspension or a spring element.
For restricting the depth of penetration and for the vertical positioning of the contact test body, it includes brim that is at least partially circumferential. Favorably, the brim is arranged at a side of the contact test body in the vicinity of a tip of the contact test body.
In one embodiment, the test device includes at least one guide element for aligning the test device at the wafer. This guide element is a pin that is aligned in one embodiment in approaching direction of the test device.
The above features may be implemented alone or in any combinations. The guide element may also include some or all features which the contact test body includes, e.g., guide edges, magnets, and/or brim(s).
A semiconductor device including at least one contact field that is adapted to be contacted by contact test bodies of a test device includes, in the region of the contact field, self-alignment device and/or a penetration restriction device, or parts thereof, for the contact test body.
The contact field is positioned in a depression of the semiconductor device, in one embodiment if the depression tapers in a funnel-shaped manner toward the contact field.
In one embodiment, a semiconductor device (chip or wafer) includes at least one magnetic element in the region of the contact field.
In one embodiment, the magnetic element is positioned directly at the contact field, in one embodiment at a side facing away from the contacting of the contact field. In another embodiment, the contact field is positioned in a depression of the semiconductor device, and at least one magnetic element is positioned at the semiconductor device at a side wall of the depression. Combinations as well as other or further positions of the magnetic elements are possible. One embodiment provides a semiconductor device in which the magnetic element includes at least one permanent magnet and/or electromagnet.
One embodiment provides a semiconductor device in which the contact field is positioned in a depression of the semiconductor device, wherein at least an aperture diameter of the depression is smaller than a pertinent diameter of a brim of a pertinent test body. One embodiment provides a semiconductor device in which the depression tapers in a funnel-shaped manner toward the contact field.
One embodiment provides a semiconductor device that includes a guide receptacle for receiving a guide element of the test device, in one embodiment a groove.
The object is also solved by a wafer with at least one chip, including at least one semiconductor device with at least one contact field that is adapted to be contacted by contact test bodies of a test device, wherein the wafer includes at least one guide receptacle for receiving a guide element of the test device, in one embodiment a groove. Of particular advantage is a design in which every chip or every semiconductor device to be individualized includes at least one guide receptacle, in one embodiment a groove. A groove or a plurality of grooves may also be provided externally of the chip, e.g., in edge regions of the wafer.
The object is also solved by systems of at least one of the above-mentioned test devices and at least one semiconductor device to be tested as described above, which are coordinated, i.e. include in one embodiment devices and counter devices for self-alignment and/or prevention of penetration, or are equipped for cooperation with same.
The object is also solved by a method for testing semiconductor devices by using a test device, in one embodiment a probe card, wherein at least one contact test body of the test device is contacted with a contact field of a semiconductor device. The method includes:
approaching the contact field by the test device; and
lateral aligning of the contact test body and/or the test device with respect to the semiconductor device by using self-alignment devices device at the contact test body and/or at the test device, at the semiconductor device or partially at the contact test body and partially at the semiconductor device and/or at the test device;
and/or the following:
approaching the contact field by the contact test body; and
putting the contact test body on the semiconductor device after contacting the contact field with a predetermined depth of penetration.
One embodiment is a method in which the process of the lateral aligning of the contact test body includes a mechanical centering of the contact test body at the semiconductor device during the introduction in a depression of the semiconductor device, wherein the contact field is positioned in the depression.
One embodiment is a method in which the process of the lateral aligning of the contact test body includes a centering of the contact test body by the interaction of electromagnetic fields, in one embodiment of magnetic fields, of the contact test body and the semiconductor device.
One embodiment is a method in which the centering of the contact test body includes an elastic deformation of the contact test body and/or a flexible deflection of the contact test body at the test device.
One embodiment is a method in which the process of the lateral aligning of the test device includes an introduction of at least one guide element, in one embodiment a guide pin, of the test device in a pertinent guide receptacle in the wafer, in one embodiment in a semiconductor device of the wafer.
The semiconductor devices to be tested which are still available on the wafer 8 (e.g., of silicon or another suitable semiconductor material such as GaAs) may, for instance, be integrated (analog, digital, and/or mixed-signal) circuits or single semiconductors, and/or semiconductor memory devices such as, for instance, functional memory devices (PLAs, PALs, etc.), or table memory devices (e.g., ROMs or RAMS), in one embodiment SRAMs or DRAMs, e.g., semiconductor devices using a clock frequency higher than 500 MHz, in one embodiment higher than 1 GHz (here e.g., DRAMs (Dynamic Random Access Memories or dynamic read-write memories) with double data rate (DDR−DRAMs=Double Data Rate, DRAMs)). The invention is, however, not restricted to a particular kind of semiconductors.
The test signals required for testing the semiconductor devices that are still available on the wafer 8 are transmitted by a test device 3 (here: a digital ATE test device) via one or a plurality of signal lines (“driver channels” 6a, 6b, 6c) to a semiconductor device test card or probe card 1 and, via contact needles 5a, 5b, 5c, 5d, 5e provided at the probe card, to contact fields (“pads”) provided on the semiconductor devices.
As results from
The signals output in reaction to the input test signals at semiconductor device connections or contact fields are, correspondingly inversely as described above, tapped by contact needles 5a, 5b, 5c, 5d, 5e of the probe card 1 and supplied, via one or a plurality of signal lines (“comparator channels” 7a, 7b, 7c) to the test device 3 where an evaluation of the signals can then take place. The driver channels and comparator channels may also be comprehended in joint input/output channels.
As results from
The semiconductor device 9 includes in the region of the contact field 12 a depression 17 in the semiconductor device with respect to a surface 29 of same, at the bottom of which the contact field 12 is positioned. The depression 17 tapers in a funnel-shaped manner from a depression aperture at the level of the edges 18 at the surface 29 of the semiconductor device 9 toward the contact field 12. The side walls of the depression 17 and the guide edge 16 thus have a similar shape in the form of a funnel or a truncated cone, in which, however, the angle of aperture of the funnel may, for instance, be different. The diameter of aperture of the depression 17, which depends on an angular position in a plane perpendicular to the z-axis, is smaller than the outer diameter of the guide edge 16.
The guide edge 16 of the test needle tip 14 forms, along with the depression 17 or its aperture edge 18, respectively, self-alignment devices, as will be explained in more detail in the following by using
Prior to approaching the contact test body 11 to the contact field (“pad”) 12, as is indicated in
On approaching the contact test body 11 to the contact field 12 in z-direction, the left region of the guide edge 16 as illustrated in
The semiconductor device 9 or the wafer including the semiconductor device 9, respectively, is of similar design as compared to the embodiment of
Already by just one of the magnets 21, 22, self-alignment devices would be provided if the opposite test needle 19 or the contact field includes paramagnetic materials such that a sufficient force can be generated for a lateral shifting of the test needle 19 toward the contact field 12. As illustrated in
In one embodiment, any other suitable flexible linking may be used instead of the cardan suspension 20, e.g., a spring or another elastic element, e.g., an elastic plastic solid body or a thin metallic interface.
Mixed forms of self-alignment devices are also possible: thus, the test tip 14 may be designed as illustrated in
Mixed forms of the semiconductor device of a combination of the embodiments according to
In
On approaching the semiconductor device 9 or the wafer, respectively, along the z-axis, the inclined test needle 24 first of all contacts the surface 29 of the semiconductor device 9 with the edge that is at the left in
By using the brim it is thus possible to firstly achieve the vertical positioning and thus the alignment of the test needle tip 26 with respect to the contact field 12. Additionally, it is possible to adjust the depth of penetration of the test needle tip 26 in the contact field 12 and to thus prevent that it penetrates too deeply and damages the contact field. The depth of penetration may be adjusted or modified by a variation of the shape of the brim and/or the shape of the depression, as well as by a suitable choice of material, e.g., a passivation.
The probe card 30 is spaced apart from the wafer 33 in z-direction. For testing the wafer 33, the probe card 30 is moved on the wafer 33 in z-direction, wherein the test needles should contact the pertinent contact fields. The wafer 33 includes a plurality of guide receptacles in the form of grooves 34 which are suited to receive one of the guide elements 32. Every chip (not illustrated) includes one of the—elliptically drawn, grooves 34. By the arrangement of grooves 34 on every chip it is possible to contact in a variable manner.
The respective guide elements 32 and guide receptacles 34 may, for simplified and precise alignment, include the same or similar features as the test needles or depressions in
Of course, the invention is not restricted to the above embodiments, but may, for instance, include different modifications and combinations.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
Number | Date | Country | Kind |
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10 2007 015 283.5 | Mar 2007 | DE | national |