Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
261 words
A process for producing a semiconductor device provided with a bipolar transistor and a gate-insulated transistor comprising the steps of: (a) forming a first semiconductor layer region of a first conductivity type on a semiconductor substrate; (b) forming a second semiconductor layer region of a second conductivity type, opposite from the first conductivity type, for providing a base region of the bipolar transistor on the semiconductor substrate; (c) forming an insulating layer on the first and second semiconductor layer regions; (d) selectively removing the insulating layer to form an aperture in an area, at least, on the second semiconductor layer region; (e) forming a first polysilicon layer on the insulating layer on the first semiconductor layer region, and a second polysilicon layer on the aperture, the first and second polysilicon layers having a first impurity of the first conductivity type; (f) implanting ions having a second impurity of the second conductivity type, utilizing the first polysilicon layer as a mask; (g) effecting thermal treatment to diffuse the first impurity of the first conductivity type from the second polysilicon layer of the aperture into the second semiconductor layer region for forming an emitter region of the first conductivity type, and to form thermal oxide layers at least on the upper and lateral faces of the first polysilicon layer for forming a gate electrode of the gate-insulated transistor; (h) implanting ions having the second impurity of the second conductivity type, utilizing the gate electrode and the thermal oxide layers as masks, so as to form source and drain regions of the gate-insulated transistor.
Claim 2
Dependent Claim
261 words
A process for producing a semiconductor device provided with a bipolar transistor and a gate-insulated transistor comprising the steps of: (a) forming a first semiconductor layer region of a first conductivity type on a semiconductor substrate; (b) forming a second semiconductor layer region of a second conductivity type, opposite from the first conductivity type, for providing a base region of the bipolar transistor on the semiconductor substrate; (c) forming an insulating layer on the first and second semiconductor layer regions; (d) selectively removing the insulating layer to form an aperture in an area, at least, on the second semiconductor layer region; (e) forming a first polysilicon layer on the insulating layer on the first semiconductor layer region, and a second polysilicon layer on the aperture, the first and second polysilicon layers having a first impurity of the first conductivity type; (f) implanting ions having a second impurity of the second conductivity type, utilizing the first polysilicon layer as a mask; (g) effecting thermal treatment to diffuse the first impurity of the first conductivity type from the second polysilicon layer of the aperture into the second semiconductor layer region for forming an emitter region of the first conductivity type, and to form thermal oxide layers at least on the upper and lateral faces of the first polysilicon layer for forming a gate electrode of the gate-insulated transistor; (h) implanting ions having the second impurity of the second conductivity type, utilizing the gate electrode and the thermal oxide layers as masks, so as to form source and drain regions of the gate-insulated transistor.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein before formation of said first semiconductor layer region, a buried layer is formed on the substrate.
Claim 4
Dependent Claim
25 words
A process according to claim 1, wherein the bipolar transistor comprises a NPN type transistor, and wherein the insulated-gate transistor comprises a P-MOS type transistor.
Claim 5
Dependent Claim
26 words
A process according to claim 3, wherein the P-MOS transistor is formed so that source and drain regions thereof comprise two regions having different impurity concentrations.
Claim 6
Dependent Claim
52 words
A process for producing a semiconductor device according to claim 1, wherein the first polysilicon layer constituting the gate electrode is so formed by etching as to have slanted lateral walls, and the thermal oxide layers are formed on the lateral faces to serve as a mask in said ion implantation step.
Claim 7
Dependent Claim
64 words
A process for producing a semiconductor device according to claim 1, wherein said thermal oxidation step is conducted by means of a wet oxidation process, and a thickness of the thermal oxide layer on the upper face of the first polysilicon layer constituting the gate electrode and a thickness of the oxide layers formed in said oxide forming step are practically equal for etching.
Claim 8
Dependent Claim
13 words
A process according to claim 1, wherein the semiconductor device comprises a diode.