In-situ spatially resolved plasma monitoring by using optical emission spectroscopy

Patent metadata

Field	Value
Publication number	US-2017254755-A1
Application number	US-201615061769-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	Mar 4, 2016
Publication date	Sep 7, 2017
Grant date	—

Abstract

Implementations of the present disclosure relate to a plasma chamber having an optical device for measuring emission intensity of plasma species. In one implementation, the plasma chamber includes a chamber body defining a substrate processing region therein, the chamber body having a sidewall, a viewing window disposed in the sidewall, and a plasma monitoring device coupled to the viewing window. The plasma monitoring device includes an objective lens and an aperture member having a pinhole, wherein the aperture member is movable relative to the objective lens by an actuator to adjust the focal point in the plasma using principles of optics, allowing only the light rays from the focal point in the plasma to reach the pinhole. The plasma monitoring device therefore enables an existing OES (coupled to the plasma monitoring device through an optical fiber) to monitor emission intensity of the species at any specific locations of the plasma.

First claim

1 . A plasma chamber, comprising:
a chamber body defining a substrate processing region therein, the chamber body having a sidewall; a viewing window disposed in the sidewall; and a plasma monitoring device coupled to the viewing window, the plasma monitoring device comprising:
an objective lens; and
an aperture member, wherein the aperture member is movable relative to the objective lens by a first actuator.

2 . The plasma chamber of claim 1 , wherein the objective lens is a converging lens.

3 . The plasma chamber of claim 1 , wherein the aperture member has a pinhole, and the pinhole is coupled to an optical fiber.

4 . The plasma chamber of claim 1 , wherein the aperture member is coupled to an optical fiber, and the optical fiber has a pinhole integrated therein at one end.

5 . The plasma chamber of claim 3 or 4 , further comprising:
an optical emission spectrometer coupled to the plasma monitoring device through the optical fiber.

6 . The plasma chamber of claim 1 , wherein the objective lens is movable horizontally by a second actuator.

7 . The plasma chamber of claim 1 , wherein the aperture member is movable horizontally and vertically with respect to the objective lens.

8 . The plasma chamber of claim 1 , wherein the plasma monitoring device is pivotally movable about a central axis vertically passing through the chamber body by the first actuator.

9 . The plasma chamber of claim 8 , wherein a longitudinal axis of the plasma monitoring device forms an angle in the range of about ±60 degrees with respect to an imaginary diameter line of the chamber body passing through the viewing window.

10 . A plasma chamber, comprising:
a chamber body defining a substrate processing region therein, the chamber body having a sidewall; a viewing window disposed in the sidewall; and a plasma monitoring device coupled to the viewing window, the plasma monitoring device comprising:
an objective lens;
an aperture member having a pinhole, wherein the aperture member is movable relative to the objective lens by a first actuator; and
a first diaphragm disposed in the light path between the chamber body and the objective lens, the first diaphragm having a first adjustable aperture.

11 . The plasma chamber of claim 10 , wherein the first diaphragm is movable with respect to the objective lens.

12 . The plasma chamber of claim 10 , further comprising:
a second diaphragm disposed in the light path between the objective lens and the aperture member, wherein the second diaphragm has a second adjustable aperture.

13 . The plasma chamber of claim 12 , wherein the second diaphragm is movable with respect to the objective lens.

14 . The plasma chamber of claim 10 , wherein the objective lens is movable with respect to the aperture member by a second actuator, and the aperture member is movable horizontally and vertically with respect to the objective lens.

15 . A method for monitoring a plasma in a process chamber, comprising:
coupling a plasma monitoring device to a viewing window disposed in a sidewall of the process chamber, wherein the plasma monitoring device comprising:
an objective lens; and
an aperture member having a pinhole;
moving the aperture member with respect to the objective lens to change a focal point in the plasma and allow light emitted from the focal point to travel through the objective lens and impinge onto the pinhole; and analyzing characteristics of the light passing through the pinhole by an optical emission spectrometer.

16 . The method of claim 15 , further comprising:
moving the aperture member horizontally and vertically with respect to the objective lens to change a focal point to different heights in the plasma.

17 . The method of claim 15 , further comprising:
moving a first diaphragm disposed in a light path between the process chamber and the objective lens, the first diaphragm having a first aperture sized to block a portion of the light from outside a focal plane of the objective lens.

18 . The method of claim 17 , further comprising:
moving a second diaphragm disposed in a light path between the objective lens and the aperture member, the second diaphragm having a second aperture sized to block a portion of the light from inside the focal plane of the objective lens.

19 . The method of claim 15 , further comprising:
pivotally moving the plasma monitoring device about a central axis vertically passing through the process chamber.

20 . The method of claim 15 , further comprising:
determining a processing end-point based on the analyzed characteristics of the light from the optical emission spectrometer.

Assignees

• Applied Materials Inc

Inventors

• Cho Tae Seung
• Kim Junghoon
• Jung Soonwook
• Park Soonam
• Lubomirsky Dmitry

Classifications

• G01J2003/126

  Focal isolation type · CPC title

• H01J2237/103

  characterised by lens type · CPC title

• H01J37/32458

  Vessel · CPC title

• H01J2237/3341

  Reactive etching · CPC title

• G01N2201/068

  Optics, miscellaneous · CPC title