Semiconductor device and method of manufacturing the same
A semiconductor wafer has a main surface. A main chip region is formed on the main surface. A sub-chip region is smaller in area than the main chip region, and positioned on an edge side of the semiconductor wafer relative to the main chip region. The sub-chip region is identical to the main chip region in design pattern. Accordingly, a semiconductor device in which occurrence of a pattern failure at the edge of the wafer can be prevented when chips are arranged in the surface of the semiconductor wafer and a method of manufacturing the same can be obtained.
1. A semiconductor device comprising:
a semiconductor wafer having a main surface;
a plurality of first chip regions arranged in matrix form in said main surface;
a plurality of second chip regions arranged adjacent to said plurality of first chip regions in said main surface to surround a periphery of a region where said plurality of first chip regions are arranged; and
a blank region arranged in an outer region on the main surface of the semiconductor wafer so that neither the first chip regions nor the second chip regions reach a circumferential edge of the semiconductor wafer, wherein
said second chip regions are smaller in area than said first chip regions,
each of the plurality of first chip regions has a first pattern,
each of the plurality of second chip regions has a second pattern,
said second pattern is formed in an identical design pattern to said first pattern, and
each of said first chip regions and said second chip regions has a rectangular shape when viewed two-dimensionally.
2. The semiconductor device according to claim 1 , wherein
each of said first pattern and said second pattern is a stripe pattern in which a plurality of pattern portions run parallel to one another.
3. The semiconductor device according to claim 2 , wherein
a width of each of said pattern portions of said first pattern is equal to a width of each of said pattern portions of said second pattern, and an interval between said pattern portions adjacent to each other of said first pattern is equal to an interval between said pattern portions adjacent to each other of said second pattern.
4. The semiconductor device according to claim 1 , wherein
each of said first pattern and said second pattern includes a plurality of grooves, and a plurality of mesa regions, and is a stripe pattern in which said grooves and said mesa regions are alternately arranged.
5. The semiconductor device according to claim 4 , wherein
each of said mesa regions of said stripe pattern as said first pattern has a width of not more than 1.5 μm.
6. The semiconductor device according to claim 4 , wherein
each of said grooves of said stripe pattern as said first pattern has an aspect ratio of not less than 6.
7. The semiconductor device according to claim 1 , further comprising a power semiconductor element having a gate electrode formed in each of said grooves of said stripe pattern as said first pattern.
8. The semiconductor device according to claim 1 , wherein
each of said first pattern and said second pattern includes a plurality of contact holes, and
said semiconductor device further comprises
a lower conducting portion positioned under a contact hole of said stripe pattern as said first pattern, and
an upper conducting portion positioned on said contact hole of said stripe pattern as said first pattern, and
said lower conducting portion is connected to said upper conducting portion through said contact hole.
9. The semiconductor device according to claim 1 , further comprising a functional element formed in said second chip region.
10. The semiconductor device according to claim 1 , wherein a size of a side of said first chip region is an integral multiple of a size of a side of said second chip region.
11. The semiconductor device according to claim 10 , wherein the integral multiple is greater than 1.
12. A method of manufacturing a semiconductor device according to claim 1 , comprising the steps of:
forming a photosensitive material on a main surface of a semiconductor wafer;
exposing a first chip formation region in which said plurality of first chip regions shall be formed of said photosensitive material to light corresponding to said first pattern;
exposing a second chip formation region in which said plurality of second chip regions shall be formed of said photosensitive material to light corresponding to said second pattern;
developing said photosensitive material having been exposed to lights corresponding to said first and second patterns, to pattern said photosensitive material; and
selectively removing a portion to be etched of said semiconductor wafer by etching with patterned said photosensitive material as a mask, to transfer said first pattern to said plurality of first chip regions corresponding to said first chip formation region in said portion to be etched, and transfer said second pattern to said plurality of second chip regions corresponding to said second chip formation region in said portion to be etched.
13. The semiconductor device according to claim 1 , wherein the blank region is interposed between the second chip regions and the circumferential edge of the semiconductor wafer.
14. The semiconductor device according to claim 1 , wherein the blank region is interposed between all of the plurality second chip regions of the semiconductor wafer and the circumferential edge of the semiconductor wafer.