Browse Prior Art Database

Etching of SiO(2) in Gaseous HF/H(2)O

IP.com Disclosure Number: IPCOM000087079D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Beyer, KD: AUTHOR [+2]

Abstract

A batch-etching system using gaseous HF/H(2)O does not cause any contamination problem on the surface of the silicon wafer because the SiO(2) is removed in the presence of gaseous HF/H(2)O mixtures, which do not contain any impurities, such as gold, copper, iron, nickel and carbon. An HF/H(2)O vapor batch-etching system for the removal of SiO(2) covering silicon wafers is shown in Fig. 1 for vertical wafer deposition and in Fig. 2 for flat wafer deposition.

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Etching of SiO(2) in Gaseous HF/H(2)O

A batch-etching system using gaseous HF/H(2)O does not cause any contamination problem on the surface of the silicon wafer because the SiO(2) is removed in the presence of gaseous HF/H(2)O mixtures, which do not contain any impurities, such as gold, copper, iron, nickel and carbon. An HF/H(2)O vapor batch-etching system for the removal of SiO(2) covering silicon wafers is shown in Fig. 1 for vertical wafer deposition and in Fig. 2 for flat wafer deposition.

After the silicon wafers are exposed to gaseous HF/H(2)O mixtures (SiO(2) removal rate for a silicon wafer placed two inches above a 49% HF-solution:. approx. 2000 Angstroms/min), the etched wafers are rinsed in DI-water.

In order to remove any copper at the silicon surface, which had accumulated prior to HF/H(2)O vapor etching,the wafers are then dipped into a nitric acid (HNO(3), 70%) solution, which dissolves the copper present at the silicon surface.

This sequence of HF/H(2)O vapor etching, DI-water rinse and nitric acid dip can be repeated as long as there is copper at the silicon surface. Following the last sequence repetition, the following cleaning process is used: Dip into heated NH(4)OH/H(2)O solution, DI-water rinse, dip into heated HCL/H(2)O(2) solution and DI-water rinse.

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