JPH11145064A - Plasma chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give plasma resistance to corrosive gas, without the inner face of a chamber being roughened, even if a worker performs plasma cleaning, using nitrogen trifluoride as cleaning gas, by applying immobilization treatment to the inner surface of a plasma chamber. SOLUTION: An immobilization film is made in the thickness of about 100 Åat the inner wall face of a plasma chamber by charging the plasma chamber made of SUS 316L arranged in a semiconductor manufacture device, and leaving it for about 48 hours. For ozone gas in high concentration, the one where the ozone gas is condensed to the concentration of about 60-100 vol.% by passing the oxygen gas lead out of an oxygen supply source 1 such a liquid oxygen gas, etc., through an ozone generator 2 thereby producing ozone gas of 5-10 vol.% and supplying ozone gas produced in an ozone condenser 3 using an absorbent such as silica gel or the like to it is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma chamber used for forming a thin film in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art In a plasma chamber used for forming a thin film in a semiconductor manufacturing process, polysilicon or amorphous silicon adheres to the inner surface of the chamber during the manufacturing process. Polysilicon and amorphous silicon adhering to the inner surface of the chamber affect the accuracy of the product, so that the adhering matter is removed by a cleaning gas such as nitrogen trifluoride.

[0003]

However, since the conventional plasma chamber has only a mirror-finished stainless steel, it is attacked with a cleaning gas at the time of cleaning. In particular, the plasma is formed using nitrogen trifluoride. At the time of vertical cleaning, there is a problem that the inner surface of the plasma chamber is corroded by fluorine and the surface is severely roughened.

The present invention has been made in view of such a point, and an object of the present invention is to provide a plasma chamber having plasma resistance to corrosive gas.

[0005]

In order to achieve the above object, the present invention according to claim 1 is characterized in that the inner surface of the plasma chamber is subjected to a passivation treatment, and is described in claim 2. According to the invention, a passivation treatment is performed by enclosing a high-concentration ozone gas in a plasma chamber.

[0006]

According to the present invention, since the inner surface of the plasma chamber is passivated, the inner surface of the chamber is not roughened even if plasma cleaning is performed using nitrogen trifluoride as a cleaning gas.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A high concentration ozone gas (60 VOL%) is sealed at room temperature in a SUS316L plasma chamber arranged in a semiconductor manufacturing apparatus and left for 48 hours, so that the inner wall surface of the plasma chamber becomes improper. A dynamic film is formed to a thickness of about 100 °.

As shown in FIG. 1, the high-concentration ozone gas supplied to the plasma chamber is supplied with an oxygen gas derived from an oxygen supply source (1) such as liquefied oxygen gas through an ozone generator (2). Ozone concentrator that generates ozone gas of about VOL% remaining oxygen and uses an adsorbent such as silica gel
By supplying the generated ozone gas to (3), an ozone gas concentrated to a concentration of about 60 to 100 VOL% is used.

FIG. 2 shows SUS316L before and after ozone treatment.
FIG. 2A shows a GDS profile before ozone treatment, and FIG. 2B shows a GD after ozone treatment.
It is an S profile, and it can be seen from these both that a passivation film was formed on the chamber surface by the treatment with ozone gas.

[0010] Nitrogen trifluoride gas diluted to 37.5% with argon was introduced into the plasma chamber whose inner surface was passivated by the ozone gas and the plasma chamber not subjected to the passivation process. 280 ° C, 0.5
The inner surface of the plasma chamber after generating plasma for 5 minutes under the conditions of Torr and 0.42 w / cm ² was visually and SEM-observed.

In the chamber not subjected to the ozone passivation treatment, the whole was changed to yellow-brown and partially purple by plasma irradiation, whereas the chamber not subjected to the ozone passivation treatment did not. There was no visible change before and after the plasma irradiation.

According to the electron micrograph of FIG. 3, it can be confirmed that the inner surface (3A) of the chamber not subjected to the passivation treatment is severely roughened by the nitrogen trifluoride plasma. (3B)
It can be confirmed that there is almost no difference from the original inner surface (3C) even after the irradiation with the nitrogen trifluoride plasma.

Further, when the fluorine concentration was analyzed by X-ray photoelectron spectroscopy at a depth of several hundred angstroms on the inner surface of the chamber, the surface without passivation was compared with the surface without passivation. About 5 times as much fluorine was detected.

[0014]

According to the present invention, since the inner surface of the plasma chamber is passivated, plasma cleaning using nitrogen trifluoride as a cleaning gas can be performed.
A plasma chamber having plasma resistance to corrosive gas without roughening the inner surface of the chamber can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a high-concentration ozone generator.

2A and 2B show GDS profiles before and after ozone treatment, FIG. 2A shows a profile before ozone treatment, and FIG. 2B shows a profile after ozone treatment.

3 is an electron micrograph when plasma irradiation is performed using nitrogen trifluoride. FIG. 3A is an electron micrograph without passivation, and FIG. 3B is an electron when passivation. A micrograph, FIG. 3C is an electron micrograph before plasma irradiation.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/31 H01L 21/31 C

Claims (2)

[Claims] 1. A plasma chamber used in semiconductor manufacturing, wherein a passivation treatment is applied to an inner surface of the chamber. 2. A plasma chamber used in semiconductor manufacturing, wherein a high-concentration ozone gas is sealed in the plasma chamber to passivate the inner surface of the plasma chamber.