Semiconductor apparatus including photodiode unit and method of inspection of the same
View Patent ↗A semiconductor apparatus has a light-receiving element. The light-receiving element has a photodiode unit having a shield film for removing noise, at least two test pads, and a shield film pseudo pattern which is formed by the same membranous type as the shield film and connected to the two test pads. The photodiode unit and the shield film pseudo pattern are integrated in one semiconductor chip. A resistance value of the shield film pseudo pattern is measured using the test pads connected to the shield film pseudo pattern. CMR of a photocoupler can be evaluated according to the correlation relationship between the measurement result and the sheet resistance of the shield film.
1. A semiconductor apparatus comprising:
a photodiode unit having a shield film that removes electric noise;
at least two test pads; and
a shield film pseudo pattern, spaced apart from the photodiode lode unit, formed by a same membranous type as the shield film, the shield film pseudo pattern being connected to the two test pads,
wherein the photodiode unit and the shield film pseudo pattern are integrated in one semiconductor chip.
2. The semiconductor apparatus according to claim 1 , wherein the shield film pseudo pattern is formed in a same layer as the shield film included in the photodiode unit.
3. The semiconductor apparatus according to claim 1 , wherein the shield film pseudo pattern is connected to a ground, and
wherein the shield film pseudo pattern has a same pattern of a sheet resistance as the shield film included in the photodiode unit.
4. The semiconductor apparatus according to claim 2 , wherein the shield film pseudo pattern is connected to a ground, and
wherein the shield film pseudo pattern has a same pattern of a sheet resistance as the shield film included in the photodiode unit.
5. The semiconductor apparatus according to claim 1 , wherein the shield film pseudo pattern is formed between the two test pads.
6. The semiconductor apparatus according to claim 2 , wherein the shield film pseudo pattern is formed between the two test pads.
7. The semiconductor apparatus according to claim 3 , wherein the shield film pseudo pattern is formed between the two test pads.
8. The semiconductor apparatus according to claim 4 , wherein the shield film pseudo pattern is formed between the two test pads.
9. A method of inspecting the semiconductor apparatus of claim 1 , the method comprising:
measuring a correlation relationship between a sheet resistance of the shield film and a common mode rejection beforehand;
measuring a resistance value of the shield film pseudo pattern; and
evaluating a common mode rejection of a photocoupler using the measured resistance value and the correlation relationship.
10. The method according to claim 9 , wherein the shield film pseudo pattern is formed in a same layer as the shield film included in the photodiode unit.
11. The method according to claim 9 , wherein the shield film pseudo pattern is connected to a ground, and
wherein the shield film pseudo pattern has a same pattern of a sheet resistance as the shield film included in the photodiode unit.
12. The method according to claim 9 wherein the shield film pseudo pattern is formed between the two test pads.
13. The method according to claim 9 , wherein one of the test pads connected to the shield film pseudo pattern is placed to a ground, and
a voltage is applied from another test pad to the semiconductor apparatus.
14. The method according to claim 10 , wherein one of the test pads connected to the shield film pseudo pattern is placed to a ground, and
a voltage is applied from another test pad to the semiconductor apparatus.
15. The method according to claim 11 , wherein one of the test pads connected to the shield film pseudo pattern is placed to a ground, and
a voltage is applied from another test pad to the semiconductor apparatus.
16. The method according to claim 12 , wherein one of the test pads connected to the shield film pseudo pattern is placed to a ground, and
a voltage is applied from another test pad to the semiconductor apparatus.
17. The semiconductor apparatus according to claim 1 , wherein a resistance value of the shield film and the shield film pseudo pattern are proportional to each other according to a size of the shield film and the shield film pseudo pattern.
18. The semiconductor apparatus according to claim 1 , wherein the shield film pseudo pattern comprises:
a shield film;
an aluminum film disposed above the shield film; and
a via hole connecting the shield film to the aluminum film.
19. The semiconductor apparatus according to claim 1 , wherein the shield film pseudo pattern comprises:
a shield film;
a plurality of aluminum films disposed above the shield film; and
a plurality of via holes connecting the shield film to the aluminum films.
20. The semiconductor apparatus according to claim 19 , wherein a first aluminum film of the plurality of aluminum films is connected to a ground and a voltage is applied through a second aluminum film of the plurality of aluminum films.