Browse Prior Art Database

Reducing Interlevel Shorts in Sputtered Insulators

IP.com Disclosure Number: IPCOM000088428D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Bialko, JA: AUTHOR [+2]

Abstract

Many interlevel shorts in sputtered SiO(2) atop semiconductor substrates are due to metallic protrusions, such as aluminum, and organic residue, such as photoresist. In particular, highly resputtered SiO(2) is especially susceptible to these types of unwanted particles on the substrate after the formation of the metal pattern. The number of interlevel shorts can be reduced by the following method.

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 74% of the total text.

Page 1 of 2

Reducing Interlevel Shorts in Sputtered Insulators

Many interlevel shorts in sputtered SiO(2) atop semiconductor substrates are due to metallic protrusions, such as aluminum, and organic residue, such as photoresist. In particular, highly resputtered SiO(2) is especially susceptible to these types of unwanted particles on the substrate after the formation of the metal pattern. The number of interlevel shorts can be reduced by the following method.

First, the glass is deposited by sputterring to a thickness sufficient to cover the metal pattern. Next, the wafers are reactively-ion-etched in a mixture of an inert gas, such as argon, and a reactive gas, such as CCl(4). During this step, the aluminum protrusions and organic residue extending up through the glass are reactively etched. Non-reactive etching of the glass by the inert gas removes a few hundred angstroms of SiO(2). This further exposes those particles which are marginally covered with glass, allowing the reactive gas to etch these particles as well. Finally, a second layer of glass is deposited to cover voids in the first glass layer which were formed after the particles were reactively etched. This two-step structure is depicted in the figure.

To avoid a discontinuous step in the glass at the interface when a via hole is etched, the second layer of glass is deposited initially (first 10 minutes) in the "zero deposition" mode. This occurs when deposition is equal to the rate of removal so that no net depo...