Browse Prior Art Database

Etchant for Cleaning Silicon Surfaces

IP.com Disclosure Number: IPCOM000080980D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Briska, M: AUTHOR [+2]

Abstract

A solution containing Hl is used to remove even traces of noble metals, such as Au and Cu, from Si surfaces.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Etchant for Cleaning Silicon Surfaces

A solution containing Hl is used to remove even traces of noble metals, such as Au and Cu, from Si surfaces.

For producing Si devices, it is necessary to immerse the Si parts several times in etchants and cleaning agents. These agents contain at least traces of metals which are nobler than Si, and which are readily absorbed on the Si surfaces. It is possible to remove these metals from the silicon surfaces by conventional etchants. But the very moment the metals are dissolved, they are reabsorbed on the Si surface, which makes their absorption more or less irreversible.

A mixture containing; 20 parts of HCl

10 parts of HI

10 parts of H(2)O

0.5 parts of HF overcomes this problem and permanently and effectively removes even traces of noble metals from the Si surfaces, without degrading the latter.

It is believed that, for example, Cu ++ ions dissolved in the mixture react according to the equations Cu/++/+ 2I/-/ -> CuI(2).

CuI(2) ---> CuI+I and that the resulting Cu + ion, due to its relatively negative electrode potential, is not reabsorbed but remains dissolved.

1