Patent EP0308814A2 successfully refreshed from Google Patents.
EP0308814A2
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EP
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Modification of interfacial fields between dielectrics and semiconductors
Assignee: National Semiconductor Corp
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Filing: 1988-09-15
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Granted: —
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Expires: 2008-09-15
Abstract
Abstract Reduction in the net charge at the interface of a dielectric and a semiconductor material is achieved by placing atomic species in the dielectric near the interface. Preferably, these species are selected from the group of alkaline earth metals. The presence of these atoms results in a redistribution of the electronic density near the interface. The placement of the atoms is effected by ion implantation followed by multiple annealing steps at alternating low and high temperatures.
Inventors
- 👤 Sheldon Aronowitz
- 👤 Kranti Anand
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 18:01
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/01346; H10D64/60; H10D64/66; H10D64/68; H10D64/691; H10P; H10P30/00; H10P30/40; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/024; Y10S148/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
54 words
A method for modifying the electrical field at the interface of a dielectric material and a semiconductor material in a monolithic circuit structure, comprising the steps of placing atoms of an alkaline earth metal in the dielectric material near the vicinity of said interface with a concentration between about 10¹²cm⁻² and about 10¹⁴cm ⁻².
Claim 2
Independent Claim
54 words
A method for modifying the electrical field at the interface of a dielectric material and a semiconductor material in a monolithic circuit structure, comprising the steps of placing atoms of an alkaline earth metal in the dielectric material near the vicinity of said interface with a concentration between about 10¹²cm⁻² and about 10¹⁴cm ⁻².
Claim 3
Dependent Claim
18 words
The method of claim 1 further including the step of annealing said structure in a non-oxidizing ambient atmosphere.
Claim 4
Dependent Claim
33 words
The method of claim 2 wherein said annealing step includes the two-step process of annealing the structure at a first temperature followed by an anneal of the structure at a second, higher temperature.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein said first temperature is less than about 600°C and said second temperature is greater than about 600°C.
Claim 6
Dependent Claim
17 words
The method of claim 3 wherein said two-step process is repeated plural times during said annealing step.
Claim 7
Dependent Claim
23 words
The method of claim 5 wherein said first temperature is less than about 600°C and said second temperature is greater than about 600°C.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein said alkaline earth metal is calcium.
Claim 9
Dependent Claim
17 words
The method of claim 1 wherein said dielectric material is SiO₂ and said semiconductor material is silicon.
Claim 10
Dependent Claim
19 words
The method of claim 1 wherein said atoms are placed in said dielectric material by means of ion implantation.
Claim 11
Dependent Claim
21 words
The method of claim 1 wherein said atoms are placed in said dielectric material by means of an ion cluster beam.
Claim 12
Dependent Claim
21 words
The method of claim 1 or 8 wherein said atoms are placed at least 2 atomic layers away from said interface.
Claim 13
Dependent Claim
20 words
The method of claim 11 wherein said atoms are placed in a range from 2-20 atomic layers from said interface.
Claim 14
Dependent Claim
21 words
The method of claim 11 wherein the presence of said atoms results in a non-positive net effective change at said interface.
Claim 15
Dependent Claim
55 words
An MOS structure having a semiconductor channel region and a gate insulator comprising an oxide of said semiconductor which forms an interface with said channel region, said gate insulator further including atoms of an alkaline earth metal distributed in said oxide in the vicinity of said interface to reduce the interfacial field of said structure.
Claim 16
Dependent Claim
55 words
An MOS structure having a semiconductor channel region and a gate insulator comprising an oxide of said semiconductor which forms an interface with said channel region, said gate insulator further including atoms of an alkaline earth metal distributed in said oxide in the vicinity of said interface to reduce the interfacial field of said structure.
Claim 17
Dependent Claim
12 words
The structure of claim 14 wherein said alkaline earth metal is calcium.
Claim 18
Dependent Claim
29 words
The structure of claim 15 wherein said calcium has a concentration of about 10¹² to 10¹⁴cm⁻³ in said oxide within a distance of 2-20 atomic layers from said interface.
References Cited (Backward Citations)
No citation records indexed.
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