Semiconductor device and manufacturing method thereof
View Patent ↗A method for improving productivity when manufacturing a semiconductor device. A lower electrode, insulating films, an upper electrode and insulating films are formed on a semiconductor substrate in a sensor region. A cavity is formed between the insulator films above the lower electrode. The lower electrode, insulating film, the cavity and insulating film, and an upper electrode form a variable capacity sensor. The cavity is formed by etching a sacrificial pattern between the insulation films by way of a hole formed in a pair of insulation films. Other than in the above sensor region, a dummy lower electrode and four insulating films are formed on the TEG region on the semiconductor substrate; and a dummy cavity is formed between a pair of insulation films above the lower electrode however no conductive layer on the same layer as the upper electrode is formed on the dummy cavity.
1. A semiconductor device whose main surface contains a sensor region where multiple sensor cells are formed, comprising:
a semiconductor substrate;
a first insulating film formed on the semiconductor substrate;
a second insulating film formed on the first insulating film;
a patterned first conducting layer formed on the second insulating film;
a third insulating film formed to cover the first conducting layer on the second insulating film; and
a fourth insulating film formed on the third insulating film,
wherein each of the multiple sensor cells in the sensor region includes:
a first cavity formed between the first insulating film and the second insulating film; and
a first electrode formed from the first conducting layer, above the first cavity,
wherein a first opening is formed on the second and the third insulating films to reach the first cavity by penetrating through the second and the third insulating films,
wherein the fourth insulating film blocks the first opening,
wherein a second cavity is formed between the first insulating film and the second insulating film, on a first region other than the sensor region on the main surface of the semiconductor device,
wherein a second opening is formed in the second and the third insulating films to reach the second cavity by penetrating through the second and the third insulating films,
wherein the fourth insulating film blocks the second opening, and
wherein among the second cavities, no first conducting layer is formed over the second cavity position farthest from the second opening.
2. A semiconductor device according to claim 1 , further comprising:
a patterned second conducting layer formed on the semiconductor substrate,
wherein the first insulating film is formed to cover the second conducting layer on the semiconductor substrate,
wherein each of the multiple sensor cells is formed from the second conducting layer on the sensor region, and
wherein the semiconductor device further comprises a second electrode formed below the first cavity.
3. A semiconductor device according to claim 2 , wherein a second conducting layer is formed below the second cavity.
4. A semiconductor device according to claim 2 , wherein each of the multiple sensor cells is a variable capacitive sensor including: a first electrode, a second electrode, a first insulating film between the first electrode and the second electrode, and a first cavity and the second insulating film.
5. A semiconductor device according to claim 1 , wherein no first conducting layer is formed over the second cavity.
6. A semiconductor device according to claim 1 , wherein the first cavity and the second cavity are the same thickness.
7. A semiconductor device according to claim 1 , wherein the second cavity is a cavity not utilized as a sensor.
8. A semiconductor device according to claim 1 , wherein the first cavity and the second cavity are the same flat shape.
9. A semiconductor device according to claim 8 , wherein the position of the first opening versus the first cavity, and the position of the second opening versus the second cavity are the same.
10. A semiconductor device according to claim 1 , wherein a second distance from a second position farthest from the second opening, to the second opening nearest the second position in the second cavity, is larger than a first distance from a first position farthest from the first opening, to the first opening nearest the first position in the first cavity.
11. A semiconductor device according to claim 10 , wherein the first cavity and the second cavity are similar flat shapes, and the second cavity is larger than the first cavity.
12. A semiconductor device according to claim 10 , wherein the flat shape of the second cavity extends in one direction, and the second opening is formed near the edge of that second cavity.
13. A semiconductor device according to claim 12 , further comprising a scaled pattern formed near the second cavity.
14. A semiconductor device according to claim 1 ,
wherein a first cavity pattern containing multiple connected first cavities formed in respective sensor cells, is formed in a sensor region,
wherein a second cavity pattern containing multiple connected second cavities and the same shape as the first cavity pattern is formed on a first region, and
wherein a position for a first opening on a first cavity pattern and, a position for a second opening on a second cavity pattern are the same.
15. A semiconductor device whose main surface contains a sensor region formed from multiple sensor cells, comprising:
a semiconductor substrate;
a patterned second conducting layer formed on the semiconductor substrate;
a first insulating film formed to cover the second conducting layer on the semiconductor substrate;
a second insulating film formed on the first insulating film;
a patterned first conducting layer formed on the second insulating film;
a third insulating film formed to cover the first conducting layer on the second insulating film; and
a fourth insulating film formed on the third insulating film,
wherein each of the multiple sensor cells in the sensor region includes:
a second electrode formed from the second conducting layer;
a first electrode formed from the first conducting layer to face the second electrode; and
a first cavity formed between the first electrode and the second electrode, and between the first insulating film and the second insulating film,
wherein a first opening is formed on the second and the third insulating films to reach the first cavity by penetrating through the second and the third insulating films,
wherein the fourth insulating film blocks the first opening,
wherein a second cavity is formed between the first insulating film and the second insulating film, on a first region other than the sensor region on the main surface of the semiconductor device,
wherein a second opening is formed in the second and the third insulating films to reach the second cavity by penetrating through the second and the third insulating films,
wherein the fourth insulating film blocks the second opening, and
wherein among the second cavities, no second conducting layer is formed below the second cavity position farthest from the second opening.
16. A semiconductor device according to claim 15 , wherein no second conducting layer is formed below the second cavity.
17. A semiconductor device according to claim 16 , wherein the semiconductor substrate is transparent to light.