SiC semiconductor device with insulating film and organic insulating layer
According to the present invention, a semiconductor device includes a first conductivity type SiC layer, an electrode that is selectively formed upon the SiC layer, and an insulator that is formed upon the SiC layer and that extends to a timing region that is set at an end part of the SiC layer. The insulator includes an electrode lower insulating film that is arranged below the electrode, and an organic insulating layer that is arranged so as to cover the electrode lower insulating film. The length (A) of the interval wherein the organic insulating layer contacts the SiC layer is 40 μm or more, and the lateral direction distance (B) along the electrode lower insulating layer between the electrode and SiC layer is 40 μm or more.
1. A semiconductor device comprising:
a SiC layer of a first conductivity type;
an electrode selectively formed on the SiC layer; and
an insulator formed on the SiC layer, reaching a dicing region provided at an end portion of the SiC layer; wherein
the insulator includes an insulating film under electrode arranged under the electrode, an organic insulating layer arranged so as to cover the insulating film under electrode, and an end insulating film that is made of a film of the same layer as that of the insulating film under electrode, the end insulating film covering the dicing region while being partly overlapped by the organic insulating layer, wherein
a distance (A) of a section where the organic insulating layer is in contact with the SiC layer is 40 μm to 180 μm, and
a lateral distance (B) between the electrode on the insulating film under electrode and the SiC layer is 40 μm to 180 μm.
2. The semiconductor device according to claim 1 , further comprising a second conductivity type region formed in the dicing region.
3. The semiconductor device according to claim 1 , wherein
the organic insulating layer does not cover the dicing region, and
an overlapped width (C) where the organic insulating layer overlaps the end insulating film is 5 μm or more and less than 100 μm.
4. The semiconductor device according to claim 2 , wherein
the organic insulating layer overlaps the end insulating film so as to selectively cover the second conductivity type region across the end insulating film, wherein
an overlapped width (C) where the organic insulating layer overlaps the end insulating film is 5 μm or more and less than 100 μm.
5. The semiconductor device according to claim 3 , wherein the end insulating film has the same thickness as that of the insulating film under electrode.
6. The semiconductor device according to claim 1 , wherein the distance (A) is 45 μm to 180 μm.
7. The semiconductor device according to claim 1 , wherein the distance (B) is 45 μm to 180 μm.
8. The semiconductor device according to claim 1 , wherein the total of the distance (A) and the distance (B) is 180 μm or less.
9. The semiconductor device according to claim 1 , wherein a breakdown voltage value (BV) is 1000 V or greater.
10. The semiconductor device according to claim 1 , wherein
the impurity concentration of the first conductivity type of the SiC layer is 1×10 14 cm −3 to 1×10 16 cm −3 , and the thickness of the SiC layer is 5 μm to 100 μm.
11. The semiconductor device according to claim 2 , further comprising a termination structure of the second conductivity type that is composed of an impurity region formed outside the electrode in the SiC layer wherein a width (F) of the second conductivity type region is greater than or equal to the difference between a width (D) of the dicing region and a width which is twice as large as a width (E) of a depletion layer extending from the termination structure, and
the width (E) of the depletion layer is calculated by the following expression (1):
Width
(
E
)
=
W
(
μm
)
=
2
ɛ
s
V
bi
q
N
B
(
1
)
wherein ε s represents a dielectric constant of SiC; V bi represents a built-in potential in the pn junction between the termination structure and the SiC layer; q represents the absolute value of the charge; and N B represents the impurity concentration of the SiC layer.
12. The semiconductor device according to claim 1 , wherein the electrode is composed of a laminate structure represented by Ti/TiN/Al—Cu.
13. The semiconductor device according to claim 1 , wherein the insulating film under electrode is composed of a SiO 2 film having a thickness of 1 μm to 5 μm.
14. The semiconductor device according to claim 13 , wherein the SiO 2 film contains phosphorus (P).
15. The semiconductor device according to claim 13 , wherein the SiO 2 film contains boron (B).
16. The semiconductor device according to claim 1 , wherein the insulating film under electrode is composed of a SiN film having a thickness of 1 to 5 μm.
17. The semiconductor device according to claim 1 , wherein the organic insulating layer is composed of a polyimide-based material.
18. The semiconductor device according to claim 1 , wherein the organic insulating layer is composed of a polybenzoxazole-based material.
19. The semiconductor device according to claim 1 , wherein the organic insulating layer is composed of an acrylic-based material.
20. The semiconductor device according to claim 1 , wherein
a MOSFET is formed in the SiC layer as a semiconductor structure, and
the electrode includes a source electrode electrically connected to a source of the MOSFET.
21. The semiconductor device according to claim 20 , wherein the MOSFET has a planar-gate structure.
22. The semiconductor device according to claim 20 , wherein the MOSFET has a trench-gate structure.
23. The semiconductor device according to claim 1 , wherein a schottky-barrier diode is formed in the SiC layer as a semiconductor element structure, and the electrode includes a schottky electrode composing part of the schottky-barrier diode.
24. The semiconductor device according to claim 1 , wherein an IGBT is formed in the SiC layer as a semiconductor element structure, and the electrode includes a source electrode electrically connected to a source of the IGBT.