METHOD AND DEVICE FOR ETCHING SILICON OR SILICON OXIDE AND METHOD AND DEVICE FOR PREPARING SAMPLE FOR ANALYZING IMPURITY

Japanese Patent JP3415273

B2

PURPOSE: To obtain a method for etching silicon without causing a large amount of industrial waste and environmental contamination by performing etching and collecting by generating silicofluoride hydrogen acid from silicon or silicon oxide using hydrofluoric acid and reproducing and collecting hydrofluoric acid by cracking silicofluoride hydrogen acid by applying plasma or high-energy light under oxidation atmosphere along with water.
CONSTITUTION: The surface of a silicon wafer 1 is oxidized and converted to silicofluoride hydrogen acid for dissolution by hydrofluoric acid gas supplied from a hydrofluoric acid solution 9, thus obtaining liquid silicofluoride hydrogen acid. The liquid silicofluoride hydrogen acid is decomposed along with water by plasma decomposition to react with steam, thus generating silicon dioxide solid and silicofluoride hydrofluoric gas. Hydrogen fluoride generated by decomposition, non-decomposed silicofluoride hydrogen acid, and silicon tetrafluoride are liquefied into solution along with steam. A solution containing hydrogen fluoride and silicofluoric hydrogen acid is accumulated in a pool 16, thus breaking an etching chamber 3 and a second condenser 6. A solution overflowed from the pool 16 is added to hydrogen fluoride solution in the etching chamber 3, becoming a supply source of hydrogen fluoride for etching a wafer.

Hideyuki Sasaki
Miyuki Takenaka
Masahiko Yoshiki
Hiroshi Yamaguchi

JP15075994A

June 09, 2003

July 01, 1994

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Toshiba Corporation

C01B33/02; C01B7/19; G01N1/28; H01L21/306; H01L21/308; (IPC1-7): H01L21/306; C01B7/19

JP3108333A
JP781902A
JP817810A

Hidekazu Miyoshi (3 outside)

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