This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-027290, filed on Feb. 24, 2021; the entire contents of which are incorporated herein by reference.
Embodiments relate to a semiconductor device manufacturing jig and a method for manufacturing the same.
There is a method in which the decrease of mechanical strength when polishing the back surface of a semiconductor substrate is suppressed by polishing only an inner part of the back surface without polishing an outer perimeter of the back surface. Also, there is a method in which a jig is used to form a metal film by electroplating the back surface of such a semiconductor substrate. In such a method for manufacturing a semiconductor device, it is desirable to suppress manufacturing process defects such as substrate cracks, chipping, etc.
According to one embodiment, a semiconductor device manufacturing jig for electroplating a substrate includes a conductive member. The substrate includes an inner part including a first surface, and an outer rim part surrounding the inner part. The outer rim part has a ring shape that protrudes further than the first surface in a direction perpendicular to the first surface. The conductive member causes a current to flow in the inner part by contacting a portion of the first surface of the inner part without contacting the outer rim part.
Various embodiments are described below with reference to the accompanying drawings.
The drawings are schematic and conceptual; and the relationships between the thickness and width of portions, the proportions of sizes among portions, etc., are not necessarily the same as the actual values. The dimensions and proportions may be illustrated differently among drawings, even for identical portions.
In the specification and drawings, components similar to those described previously or illustrated in an antecedent drawing are marked with like reference numerals, and a detailed description is omitted as appropriate.
The semiconductor device manufacturing jig 100 is a jig for forming a metal film on a substrate by electroplating a semiconductor substrate when manufacturing the semiconductor device. The semiconductor device manufacturing jig 100 includes the conductive member 10 illustrated in
The conductive member 10 is a ring-shaped member. More specifically, the conductive member 10 includes a first part 11 that is ring-shaped when viewed along a direction D10 shown in
The tip in the direction D10 of the second part 12 is a contact part 12c that contacts the substrate to be processed in the plating process. The contact part 12c protrudes in the direction D10 with respect to the second part 12 and is located along the outer perimeter of the second part 12. The contact part 12c has a constant height and width, and has a continuous ring shape around the entire perimeter of the second part 12. In the plating process, a current flows from the conductive member 10 into the substrate to be processed via the contact part 12c. As illustrated in
In the example, a groove 13g is formed in the end surface in the direction D10 of the third part 13. The groove 13g is continuous around the entire perimeter of the third part 13. As described below, the groove 13g is provided so that the conductive member 10 and the cover member 20 can engage. However, according to the embodiment, the groove 13g may not always be provided.
For example, the conductive member 10 (the first part 11, the second part 12, and the third part 13) are formed of a metal. The conductive member 10 includes, for example, at least one of iron, chrome, nickel, copper, or aluminum. The conductive member 10 may include, for example, stainless steel. The first part 11, the second part 12, and the third part 13 are, for example, a metal member that is formed to have a continuous body.
The ring part 21 is ring-shaped when viewed along a direction D20. The protrusion 22 protrudes from the ring part 21 in the direction D20. The protrusion 22 has a continuous ring shape around the entire perimeter of the ring part 21. The protrusion 22 corresponds to the groove 13g of the conductive member 10. However, according to the embodiment, the protrusion 22 may not always be provided. For example, an insulator such as a resin or the like is used as the material of the cover member 20.
A portion of a semiconductor element is formed at the front surface 30a side. In the example of
The front surface 30a is, for example, a plane. On the other hand, the back surface 30b includes a larger unevenness than the front surface 30a. Specifically, the substrate 30 includes an inner part 31 (a membrane) that is recessed, and an outer rim part 32 (a rim) that is a protrusion. As illustrated in
The outer rim part 32 has a ring shape that surrounds the outer perimeter of the inner part 31. The outer rim part 32 protrudes further than the first surface 31f in the direction D30. A thickness T32 (the length along the direction D30) of the outer rim part 32 is greater than a thickness T31 of the inner part 31.
In other words, the back surface 30b includes a protrusion region 30p that is the surface of the outer rim part 32, and a recess region 30q that is the surface of the inner part 31. A sloped surface 30s is located between the protrusion region 30p and the recess region 30q of the back surface 30b. The sloped surface 30s connects the protrusion region 30p and the recess region 30q. For example, the protrusion region 30p and the recess region 30q are perpendicular to the direction D30; and the sloped surface 30s is tilted with respect to the protrusion region 30p and the recess region 30q. Thus, a step (an elevation difference) is formed between the inner part 31 and the outer rim part 32. The sloped surface 30s may be a side surface that is substantially perpendicular to the protrusion region 30p.
As illustrated in
The semiconductor part 34 and the outer rim part 32 include, for example, silicon, silicon carbide, gallium nitride, or gallium arsenide as a semiconductor material. For example, a semiconductor element such as a MOSFET or the like is formed by ion-implanting an n-type impurity and a p-type impurity into the semiconductor material. Arsenic, phosphorus, or antimony can be used as the n-type impurity. Boron can be used as the p-type impurity. The gate electrode of the semiconductor element includes, for example, a conductive material such as polysilicon doped with an impurity, etc. The source electrode of the semiconductor element includes, for example, a metal such as aluminum, copper, silver, titanium, tungsten, etc. A protective layer of the semiconductor element includes, for example, an insulating material such as polyimide, etc. The conductive layer 33 includes, for example, at least one of titanium, aluminum, nickel, copper, silver, or tungsten.
In the plating process as illustrated in
In the plating process as illustrated in
More specifically, the conductive layer 33 includes an outer perimeter portion 33a that contacts the contact part 12c, and a central portion 33b that is surrounded with the outer perimeter portion 33a. The outer perimeter portion 33a includes the end portion of the conductive layer 33 and has a ring shape that surrounds the central portion 33b. In other words, the contact part 12c has a ring shape that contacts the outer perimeter portion 33a of the conductive layer 33. In the plating process, the contact part 12c contacts the surface of the outer perimeter portion 33a of the conductive layer 33 (i.e., a portion of the first surface 31f) and causes a current to flow in the conductive layer 33.
In the plating process, only the contact part 12c of the conductive member 10 contacts the substrate 30. The conductive member 10 does not contact the outer rim part 32 (the sloped surface 30s and the protrusion region 30p).
A protective tape 43 is adhered on the front surface 30a of the substrate 30. The cover member 20 contacts the protective tape 43 and supports the front surface 30a side of the substrate 30 via the protective tape 43. The cover member 20 (the ring part 21) overlaps the contact part 12c in the direction D30 and clamps the inner part 31 of the substrate 30 with the contact part 12c.
A width W12 (the length in a direction D31 that is perpendicular to the direction D30) of the second part 12 is, for example, not less than 1.0 mm and not more than 3.0 mm. A length W14 in the direction D31 between the second part 12 and the third part 13 is greater than a width W32 (the length along the direction D31) of the outer rim part 32. The length W14 is, for example, not less than 2.5 mm and not more than 4.5 mm. A height H12 of the second part 12 (the length of the protrusion from the first part 11) is greater than a difference H32 between the thickness of the outer rim part 32 and the thickness of the inner part 31. The height H12 is, for example, not less than 0.7 mm and not more than 1.0 mm. A difference H14 between the height of the second part 12 and the height of the third part 13 is substantially equal to the sum of the thickness of the inner part 31 and the thickness of the protective tape 43.
An inner diameter 10D of the conductive member 10 (referring to
The conductive member 10 and the cover member 20 are fixed by being clamped by a clip 44 that is made of, for example, a resin in a state in which the conductive member 10 and the cover member 20 clamp the substrate 30.
As illustrated in
As illustrated in
As illustrated in
The backgrinding tape 61 is peeled as illustrated in
As illustrated in
As illustrated in
As illustrated in
As illustrated in
In a plane perpendicular to the direction D30, the cut position P1 is the position of a portion (i.e., the outer perimeter portion 33a) of the inner part 31 contacted by the contact part 12c of the conductive member 10 in the plating process. The cut position P1 is circular when viewed along the direction D30.
Effects according to the embodiment will now be described.
Conversely, according to the embodiment as described with reference to
The conductive member 10 does not contact the outer rim part 32 in the plating process. Thereby, the formation of the metal film 50 at the outer rim part 32 and at the end portion of the outer rim part 32 is suppressed because the flow of the current in the outer rim part 32 and in the end portion of the outer rim part 32 is suppressed.
The conductive layer 33 is located only at the inner part 31. The contact part 12c has a ring shape that contacts the outer perimeter portion 33a of the conductive layer 33. Thereby, for example, the metal film 50 can be formed only on the central portion 33b of the conductive layer 33 (the portion other than the outer perimeter portion 33a of the conductive layer 33); and the formation of the metal film 50 at the outer perimeter portion 33a and at the outer side of the outer perimeter portion 33a can be suppressed. In other words, the formation of the metal film 50 at the outer rim part 32 and at the end portion of the outer rim part 32 can be suppressed.
In the plating process, the cover member 20 overlaps the contact part 12c in the direction D30 and clamps the substrate 30. By fixing the conductive member 10 and such a cover member 20 by clamping by the clip 44, the substrate 30 can be stably supported, the contact part 12c and the first surface 31f can be closely adhered, and the metal film 50 can be stably formed.
As described with reference to
For example, when the semiconductor element that is provided in the substrate 30 is a vertical MOSFET, the metal film 50 performs the role of a drain electrode. For example, when the semiconductor device is a shared-drain-electrode MOSFET, a current flows between two MOSFETs via the drain electrode (the metal film 50). In such a case, it is desirable for the metal film 50 to be thick. The resistance of the drain electrode can be reduced thereby, and the on-resistance of the semiconductor elements can be reduced. On the other hand, when the metal film 50 is thick, the stress that the metal film 50 applies to the substrate 30 may increase. In such a case as well, according to the embodiment, the formation of the metal film 50 at the outer rim part 32 and at the end portion of the outer rim part 32 can be suppressed; therefore, substrate cracks can be suppressed.
When the metal film that is cut by the dicing blade is thick, there is a risk that clogging of the dicing blade and chipping may easily occur. Conversely, according to the embodiment, for example, the metal film 50 is not formed at the cut position P1 in the cutting process; therefore, chipping can be suppressed even when the metal film 50 is thick.
For example, when the semiconductor element that is provided in the substrate 30 is a vertical MOSFET, the on-resistance can be reduced by thinning the inner part 31. On the other hand, when the inner part 31 is thinned, there is a risk that the strength of the substrate may decrease. Conversely, according to the embodiment, the chipping in the cutting process can be suppressed as described above; therefore, the inner part 31 is easily thinned.
According to the embodiment as described above, manufacturing process defects such as substrate cracks, chipping, etc., can be suppressed.
In the example as illustrated in
As illustrated in
In a plane perpendicular to the direction D30, the cut position P2 is the position of a portion of the inner part 31 (i.e., the outer perimeter portion 33a) that is contacted by the contact part 12c of the conductive member 10 in the plating process. The cut position P2 is circular when viewed along the direction D30.
Thus, the substrate 30 may be cut from the front surface 30a side by adhering a dicing tape to the back surface 30b side of the substrate 30. In such a case, a tape transfer process such as that described with reference to
On the other hand, as described with reference to
According to embodiments, a semiconductor device manufacturing jig and a method for manufacturing a semiconductor device can be provided in which manufacturing process defects can be suppressed.
In the specification of the application, “perpendicular” refers to not only strictly perpendicular but also include, for example, the fluctuation due to manufacturing processes, etc. It is sufficient to be substantially perpendicular.
Hereinabove, exemplary embodiments of the invention are described with reference to specific examples. However, the embodiments of the invention are not limited to these specific examples. For example, one skilled in the art may similarly practice the invention by appropriately selecting specific configurations of components included in semiconductor device manufacturing jigs from known art. Such practice is included in the scope of the invention to the extent that similar effects thereto are obtained.
Further, any two or more components of the specific examples may be combined within the extent of technical feasibility and are included in the scope of the invention to the extent that the purport of the invention is included.
Moreover, all semiconductor device manufacturing jigs, and methods for manufacturing semiconductor devices practicable by an appropriate design modification by one skilled in the art based on the semiconductor device manufacturing jigs, and the methods for manufacturing semiconductor devices described above as embodiments of the invention also are within the scope of the invention to the extent that the purport of the invention is included.
Various other variations and modifications can be conceived by those skilled in the art within the spirit of the invention, and it is understood that such variations and modifications are also encompassed within the scope of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
Number | Date | Country | Kind |
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2021-027290 | Feb 2021 | JP | national |
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20220267920 A1 | Aug 2022 | US |