EP0244367A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mos type integrated semiconductor device with nonuniform thickness of gate oxide and process for fabricating it
Assignee: STMicroelectronics SRL
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Filing: 1987-03-25
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Granted: —
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Expires: 2007-03-25
Abstract
Abstract In an integrated MOS device, MOS transistors belonging to circuit sections destined to operate at different voltages are provided with an insulating layer of gate oxide of thickness suitably differentiated through a modification of known fabrication processes, increasing it in the case of transistors subject to higher supply voltages.
Inventors
- 👤 Paolo Picco
- 👤 Tiziana Cavioni
- 👤 Alfonso Maurelli
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 07:10
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0144; H10D84/02; H10D84/03; H10D84/038; H10D84/80; H10D84/82; H10D84/83; H10D84/8314
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
55 words
A MOS type integrated device comprising at least two MOS transistors wherein the insulating layer of oxide present under the gate electrode of at least one of said MOS transistors has a thickness substantially different from the thickness of the insulating layer of oxide present under the gate electrode of another of said MOS transistors.
Claim 2
Dependent Claim
55 words
A MOS type integrated device comprising at least two MOS transistors wherein the insulating layer of oxide present under the gate electrode of at least one of said MOS transistors has a thickness substantially different from the thickness of the insulating layer of oxide present under the gate electrode of another of said MOS transistors.
Claim 3
Dependent Claim
87 words
A device according to claim 1 comprising at least a circuit section containing a plurality of MOS transistors destined to operate with a first supply voltage and at least another circuit section containing a plurality of MOS transistors destined to operate with a second supply voltage greater that said first supply voltage; the MOS transistors belonging to said second circuit section having an insulating layer of oxide under the respective gate electrodes of thickness substantially greater than that of MOS transistors belonging to said first circuit section.
Claim 4
Dependent Claim
140 words
In a process for fabricating MOS type integrated semiconductor devices containing MOS transistors destined to operate with a first supply voltage and MOS transistors destined to operate with a second supply voltage higher than said first voltage, the improvement characterized in that the process comprises the following stages: a) forming a first layer of gate oxide over areas where said transistors will be formed; b) masking the layer of oxide formed during the previous stage in correspondence of areas where said MOS transistors destined to operate with said second supply voltage will be formed; c) removing the layer of oxide formed during the stage a) from areas unmasked by the mask set during the stage b); d) removing the residual masking material; and e) forming a second layer of gate oxide over the areas where said transistors will be formed.
Claim 5
Dependent Claim
140 words
In a process for fabricating MOS type integrated semiconductor devices containing MOS transistors destined to operate with a first supply voltage and MOS transistors destined to operate with a second supply voltage higher than said first voltage, the improvement characterized in that the process comprises the following stages: a) forming a first layer of gate oxide over areas where said transistors will be formed; b) masking the layer of oxide formed during the previous stage in correspondence of areas where said MOS transistors destined to operate with said second supply voltage will be formed; c) removing the layer of oxide formed during the stage a) from areas unmasked by the mask set during the stage b); d) removing the residual masking material; and e) forming a second layer of gate oxide over the areas where said transistors will be formed.
References Cited (Backward Citations)
No citation records indexed.
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