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US 6,475,862 B1Granted
Semiconductor device having gate insulating layers different in thickness and material and process for fabrication thereof
AssigneeNEC Corporation
InventorKoichi Ando
Life of this patent
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Abstract
Field effect transistors of an integrated circuit are fabricated on a silicon substrate, and require gate insulating layers appropriate for the purpose of individual component circuits, the active areas assigned the field effect transistors are sequentially exposed to source gas varied in the ratio between oxygen and nitrogen for growing silicon oxide and/or silicon oxynitride thereon, and the nitrogen serves as a diffusion inhibitor against the oxygen so as to form the gate insulating layers different in thickness of the order of several angstroms.
Claims11
A process for fabricating a semiconductor device, comprising the steps of:
- a) preparing a substrate formed of semiconductor material and having plural portions selectively assigned to plural circuit components of an integrated circuit;
- b) growing a first insulating layer formed of a first kind of insulating material containing an oxidizing agent diffused therethrough and reactive with said semiconductor material and a diffusion inhibitor against the diffusion of said oxidizing agent on one of said plural portions of said substrate, a first amount of said diffusion inhibitor being at a first ratio to a first amount of said oxidizing agent;
- c) growing a second insulating layer formed of a second kind of insulating material containing said oxidizing agent and said diffusion inhibitor on another portion of said substrate so as to form a first dielectric layer having at least said first insulating layer and a second dielectric layer different in thickness from said first dielectric layer and having at least said second insulating layer for one of said plural circuit components and another of said plural circuit components, respectively, a second amount of said diffusion inhibitor in said second insulating layer being at a second ratio to a second amount of said oxidizing agent in said second insulating layer;
- and
- d) forming a gate electrode on each of said first dielectric layer and said second dielectric layer.
2 more elements
A process for fabricating a semiconductor device, comprising the steps of:
- a) preparing a substrate formed of semiconductor material and having plural portions selectively assigned to plural circuit components of an integrated circuit;
- b) growing a first insulating layer formed of a first kind of insulating material containing an oxidizing agent diffused therethrough and reactive with said semiconductor material and a diffusion inhibitor against the diffusion of said oxidizing agent on one of said plural portions of said substrate;
- c) growing a second insulating layer formed of a second kind of insulating material containing said oxidizing agent on said one of said plural portions and another portion of said substrate so as to form a first dielectric layer having at least said first and second insulating layers and a second dielectric layer different in thickness from said first dielectric layer and having said second insulating layer for one of said plural circuit components and another of said plural circuit components, respectively;
- and
- d) forming a gate electrode on each of said first dielectric layer and said second dielectric layer;
- and
- further comprising the step of e) growing third insulating layers formed of a third kind of insulating material containing said oxidizing agent and said diffusion inhibitor different in ratio from that of said first kind of insulating material on said one of said plural portions and yet another portion of said substrate between said step b) and said step c) so that said first dielectric layer further has said third insulating layer, and said yet another portion is covered with a third dielectric layer different in thickness from said first and second dielectric layers and having said second and third insulating layers in said step c).
4 more elements
A process for fabricating a semiconductor device, comprising the steps of:
- a) preparing a substrate formed of semiconductor material and having plural portions selectively assigned to plural circuit components of an integrated circuit;
- b) growing a first insulating layer formed of a first kind of insulating material containing an oxidizing agent diffused therethrough and reactive with said semiconductor material and a diffusion inhibitor against the diffusion of said oxidizing agent on one of said plural portions of said substrate;
- c) growing a second insulating layer formed of a second kind of insulating material containing said oxidizing agent on said one of said plural portions and another portion of said substrate so as to form a first dielectric layer having at least said first and second insulating layers and a second dielectric layer different in thickness from said first dielectric layer and having said second insulating layer for one of said plural circuit components and another of said plural circuit components, respectively;
- and
- d) forming a gate electrode on each of said first dielectric layer and said second dielectric layer;
- and
- further comprising the step of e) growing third insulating layers formed of a third kind of insulating material containing said oxidizing agent and said diffusion inhibitor smaller in ratio than said first kind of insulating material on said one of said plural portions and yet another portion of said substrate between said step b) and said step c).
4 more elements
Dependencies are inferred from the claim text.