Browse Prior Art Database

Passivation Patterning Technique

IP.com Disclosure Number: IPCOM000046539D
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Van Vechten, JA: AUTHOR

Abstract

Electron beam patterning of silicon oxide may be carried out without lithographic steps by condensing a layer of oxygen molecules on a silicon wafer cooled to 55ŒK or below and activating localized low temperature oxidation by means of an electronically positioned electron beam. Oxidation of Si proceeds by migration of oxygen ions, O- or O-2 or O-2, or neutral O atoms or molecules through the oxide which has already formed. In thermal oxidation this migration is thermal diffusion. High temperatures required for appreciable rates and the difference in thermal coefficients of expansion between Si and SiO2 (aSi > aSiO2) are sources of defects in device fabrication. It is known that rates of oxidation can be greatly accelerated by the application of high electric field (107 V/an), as in plasma 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 58% of the total text.

Page 1 of 2

Passivation Patterning Technique

Electron beam patterning of silicon oxide may be carried out without lithographic steps by condensing a layer of oxygen molecules on a silicon wafer cooled to 55OEK or below and activating localized low temperature oxidation by means of an electronically positioned electron beam. Oxidation of Si proceeds by migration of oxygen ions, O- or O-2 or O-2, or neutral O atoms or molecules through the oxide which has already formed. In thermal oxidation this migration is thermal diffusion. High temperatures required for appreciable rates and the difference in thermal coefficients of expansion between Si and SiO2 (aSi > aSiO2) are sources of defects in device fabrication.

It is known that rates of oxidation can be greatly accelerated by the application of high electric field (107 V/an), as in plasma oxidation. This enhances the migration of negative oxygen ions (O-).

Still, temperatures of the order 600OEC are employed, and oxide quality and silicon damage remain problems. Thermal excitation remains responsible for most of the jumps in the ion migration process, i.e., most of the WHm still comes from lattice heat. This technique uses an electron beam directly on liquid O2 on the sample to define an oxidized area and to cause migration required for oxidation. Thermal migration is not required. The oxygen ions (atoms also) are driven through the interstitial channels of the oxide already present by impact from the low energy electron beam in...