Browse Prior Art Database

Uniform Removal of Liquid HF Etchant From Patterned Wafers

IP.com Disclosure Number: IPCOM000102697D
Original Publication Date: 1990-Dec-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Agnello, PD: AUTHOR [+2]

Abstract

Disclosed is a process for removing HF containing etchant liquids uniformly and completely from oxide patterned Si wafers.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 70% of the total text.

Uniform Removal of Liquid HF Etchant From Patterned Wafers

       Disclosed is a process for removing HF containing etchant
liquids uniformly and completely from oxide patterned Si wafers.

      Bare Si wafers may be etched free of native oxide by dipping
into HF:Water = 1:10 solution just prior to epitaxial growth without
a water rinse step.  Omitting the final water rinse eliminates the
possibility of slight reoxidation.  This procedure has been exploited
to produce high-quality defect-free epitaxial layers grown at low
temperatures without the use of a high temperature in-situ reduction
step (1).

      Unfortunately, this procedure does not work well on wafers with
patterned oxides and nitrides because the patterned areas are
hydrophilic and the wafer retains droplets of etch solution on these
areas.  An etching technique using a spinner where a sequence of
ethanol, HF etch solution, and ethanol solution are sprayed onto the
wafer while spinning is reported in (2).  This procedure used a spin
speed of 12,000 rpm which removed most of the liquid but also
produced an airborne HF aerosol which is a safety and wafer
recontamination hazard.  The use of ethanol and methanol also leads
to rapid evaporation during spinning and to droplet formation at the
edges of the wafer.

      This article consists of adding a particular alcohol to the HF
solution under particular conditions to facilitate the wetting of
both bare Si and oxide or nitride areas.  The c...