Chamber cleaning method using F2 and a process for manufacture of F2 for this method

Patent metadata

Field	Value
Publication number	US-9757775-B2
Application number	US-201314426510-A
Country	US
Kind code	B2
Filing date	Sep 6, 2013
Priority date	Sep 10, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

Elemental fluorine is often manufactured electrochemically from a solution of KF in hydrogen fluoride and contains varying amounts of HF as impurity. The present invention provides a method for chamber cleaning using F 2 which contains more than 0.1% by weight and equal to or less than 10% by weight of HF. Surprisingly, such an F 2 is very well suited for the purpose of chamber cleaning. In a preferred embodiment, the F 2 which contains more than 0.1% by weight and less than 2.5% by weight of HF is electrolytically produced, cleaned, delivered and used on site, without any pressurizing treatment. Omitting cleaning steps and process and using process conditions leaving a relatively high HF content in the F 2 allows at the same time to omit pressurizing steps. The advantage is that less cleaning steps.

First claim

The invention claimed is:

1. A method for the cleaning of chambers, the method comprising using F 2 which contains more than 0.01% by weight and less than 0.5% by weight of HF;
wherein the applied F 2 is obtained in a process comprising the following steps (I) and (II):
A step (I) comprising:
A) at least one step of electrolytically producing raw F 2 from HF in the presence of KF
B) at least one step of removing particles entrained in the raw F 2 obtained in step A)
C) at least one step of filtering any remaining particles out of the F 2 leaving step B) by passing the F 2 through a filter
and
D) a step of providing the F 2 to a buffer tank or a storage tank;

and
A step (II) wherein F 2 is withdrawn from the buffer tank or storage tank and delivered to the chamber to perform at least one step of chamber cleaning;

wherein the steps A) to D) are performed on the site of chamber cleaning;
wherein step A) is performed in an electrolyzer, step B) is performed in a static scrubber, step C) is performed using a metallic filter, step D) is performed in a buffer tank or storage tank, and the F 2 leaving step D) is delivered to at least one chamber and used in the chamber in a chamber cleaning step (II), wherein the electrolyzer, the static scrubber, the metallic filter, the buffer tank or storage tank, and the at least one chamber are operably connected; and
wherein the pressure of the F 2 in step B) is lower than the pressure of F 2 in step A), the pressure of the F 2 in step C) is lower than the pressure of F 2 in step B), the pressure of the F 2 in step D) is lower than the pressure of F 2 in step C), and the pressure of the F 2 in step (II) is lower than the pressure of F 2 in step D).

2. The method of claim 1 wherein the chamber is a CVD chamber.

3. The method of claim 1 wherein the chamber is used during the manufacture of a semiconductor, a micro-electromechanical system, TFT (flat panel display) or a solar cell for depositing at least one layer.

4. The method of claim 1 wherein the filter of step C) comprises pores having a diameter between 0.01 and 20 μm.

5. The method of claim 1 wherein the F 2 pressure in step A) is equal to or lower than 1.1 bar (abs).

6. The method of claim 1 wherein the F 2 is delivered to the chamber in step (II) at a pressure from equal to or greater than 0.2 bar (abs) to equal to or lower than 0.55 bar (abs).

7. The method of claim 1 wherein the F 2 is not subjected to a pressurizing treatment.

8. The method of claim 1 wherein the filter used in step C) is cleaned with liquid HF.

9. The method according to claim 8 wherein the liquid HF is recovered and fed to a step of electrolytically producing F 2 .

Assignees

• Solvay

Inventors

• Diana Oliviero

Classifications

• C25B1/245

  Fluorine; Compounds thereof · CPC title

• B08B5/00 Primary

  Cleaning by methods involving the use of air flow or gas flow (cleaning hollow articles by methods or apparatus specially adapted thereto B08B9/00) · CPC title

• C23C16/4405 Primary

  Cleaning of reactor or parts inside the reactor by using reactive gases · CPC title

• C25B15/08

  Supplying or removing reactants or electrolytes; Regeneration of electrolytes · CPC title

• Y02P20/123

  Cross-Sectional Technologies · mapped topic