Browse Prior Art Database

Sidewall Passivation and Insulation Using a Silicon Dioxide Silicon Nitride Barrier

IP.com Disclosure Number: IPCOM000048165D
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Domenicucci, AG: AUTHOR [+3]

Abstract

In any double polysilicon process it is essential that there be a sufficient amount of silicon dioxide to insulate between the polysilicon lands. There are two cases to consider: 1. the silicon dioxide that lies directly on top of the first polysilicon layer, which consists of, for example, a low pressure chemical vapor deposited (LPCVD) oxide and thermally deposited oxide 11, and 2. the silicon dioxide that must cover the side of the This oxide is grown during the Gate II oxidation.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 96% of the total text.

Page 1 of 2

Sidewall Passivation and Insulation Using a Silicon Dioxide Silicon Nitride Barrier

In any double polysilicon process it is essential that there be a sufficient amount of silicon dioxide to insulate between the polysilicon lands. There are two cases to consider: 1. the silicon dioxide that lies directly on top of the

first polysilicon layer, which consists of, for example,

a low pressure chemical vapor deposited (LPCVD) oxide

and thermally deposited oxide 11, and

2. the silicon dioxide that must cover the side of the

This oxide is grown during the Gate II oxidation.

The first case can easily be controlled by the LPCVD process. The second case is dependent on the Gate II oxidation and the oxidation rate of the Poly I (which is dependent on temperature and doping concentration). There is the possibility that the oxide grown on the side of the Poly I may be thinned even further due to the "lifting" of the poly at its edges. Therefore, it is desirable to improve the sidewall oxide integrity. This can be accomplished by the deposition of a thin layer 10 of silicon nitride over the silicon dioxide layer 11 after the growth of Gate II gate silicon dioxide dielectric layer 9. The silicon nitride also is deposited upon the side of the Poly due to the nature of the low pressure chemical vapor deposition process used. Since the dielectric strength of silicon nitride is higher than that of silicon dioxide, the silicon nitride will improve the overall sidewall integrity.

1

Pa...