JP-2026514337-A - Real-time radical output monitoring using optical emission spectroscopy.

Abstract

A system for determining the concentration of radicals in a particle stream delivered into a semiconductor processing chamber comprises a plasma generator, a spectrometer optically coupled to the glow discharge region of the plasma generator, and a controller communicatively coupled to the spectrometer. The plasma source is operable to generate a glow discharge to excite radicals and diluent gases in the accepted effluent stream. The spectrometer is operable to output measurement data representing the intensity of light emitted by the excited radicals and diluent gases. The controller is operable to calculate the concentration of radicals in the effluent stream based on the measurement data. [Selection Diagram] Figure 1

Inventors

• ポキドブ，イリヤ
• ローゼンツヴァイク，ガイ
• ハロック，ロバート
• ロバーツ，マーク

Assignees

• エムケーエス インコーポレイテッド

Dates

Publication Date

20260511

Application Date

20240319

Priority Date

20230321

Claims (11)

1. A system for determining the concentration of radicals in a particle stream generated by plasma delivered into a semiconductor processing chamber, A plasma generator having an inlet configured to receive an outflow of a particle stream containing radicals and diluent gases, wherein the plasma source is operable to generate a glow discharge to excite the radicals and diluent gases in the received outflow. A spectrometer optically coupled to the internal glow discharge region of the plasma generator, the spectrometer being operable to output measurement data representing the intensity of light emitted by the radicals and the diluent gas, A controller that is communicatively coupled to the spectrometer and is operable to calculate the concentration of radicals in the outflow based on the measurement data, A system equipped with these features.
2. The system according to claim 1, wherein the plasma generator is externally operable outside the semiconductor processing chamber.
3. The system according to claim 1, wherein the plasma generator is an in-situ plasma generator capable of operating within the semiconductor processing chamber.
4. The system according to claim 1, wherein the spectrometer is a continuous-wavelength spectrometer.
5. The system according to claim 1, wherein the spectrometer is a discrete-wavelength spectrometer.
6. The system according to claim 1, wherein the controller is operable to generate one or more commands effective for controlling the operation of the particle flow source.
7. The system according to claim 1, further comprising a light-shielding feature coupled to the inlet of the plasma source, wherein the light-shielding feature is configured to transport the outflow but prevent light emitted by the remote plasma source from reaching the plasma generator.
8. The system according to claim 7, wherein the light-shielding feature includes at least one selected from the group consisting of a bent portion, a baffle, and a screen.
9. The system according to claim 1, further comprising a viewport coupled to the plasma source, wherein the viewport is configured to transmit light emitted by the excited radicals and diluent gas in the received outflow stream.
10. The system according to claim 1, further comprising a remote plasma source fluidically coupled to the inlet of the plasma generator, wherein the remote plasma source is operable to generate the outflow.
11. A particle flow delivery system used in conjunction with a semiconductor processing chamber, A remote plasma source capable of generating an outflow of particle streams containing radicals and diluent gases, A plasma generator having an inlet configured to receive the outflow and an outlet configured to be coupled to the semiconductor processing chamber, wherein the plasma source is operable to generate a glow discharge for exciting the radicals and diluent gas in the outflow and to transport the outflow to the semiconductor processing chamber, A light-shielding feature portion is disposed between the remote plasma source and the plasma generator, wherein the light-shielding feature portion transports the outflow but is configured to prevent light emitted from the remote plasma source from reaching the plasma generator, A spectrometer optically coupled to the internal glow discharge region of the plasma source, and capable of outputting measurement data representing the intensity of light emitted by the radicals and the diluent gas, A controller that is communicatively coupled to the spectrometer and is operable to calculate the concentration of radicals in the outflow based on the measurement data, A particle flow delivery system equipped with the following features.

Description

Background : Embodiments of the present invention broadly relate to optical emission spectroscopy (OES) radical detection systems and methods for radical detection using optical emission spectroscopy. More specifically, embodiments of the present invention relate to measuring the concentration of radical species in the effluent of a remote plasma source used in plasma-assisted semiconductor manufacturing processes, such as plasma-enhanced atomic layer deposition (PEALD), plasma-enhanced chemical vapor deposition (PECVD), or plasma etching. In semiconductor manufacturing processes, plasma sources are used to generate particles that can be used to facilitate etching and deposition processes, as well as to clean the internal surfaces of the semiconductor processing chamber. Radicals are often a significant component in particle streams due to their high reactivity caused by unpaired electrons. Remote plasma sources are often used to generate radical-containing particle streams at a location away from the semiconductor processing chamber. However, radicals may be destroyed while being transported to the semiconductor processing chamber. For example, a remote plasma source can generate atomic fluorine radicals by dissociating NF3 molecules (i.e., NF3 → N + 3F), but these fluorine radicals may recombine with molecular fluorine via gas-phase and surface reactions (e.g., F + F → F2 ). Therefore, it may be desirable to measure the concentration of radicals in the particle effluent stream generated by the remote plasma source and adjust the operation of the remote plasma source and/or other components of the semiconductor processing system to correct or compensate for the destruction of radicals generated by the remote plasma source. One known method for measuring radicals in particle streams is calorimetry, which measures the amount of thermal energy released as a result of radicals recombining with stable molecules. This method is unsuitable for use in semiconductor processing because it inevitably leads to the destruction (recombination) of the radicals being measured. The same applies to other known measurement methods, such as etching rate measurement and chemical titration. While it is possible to divert a small portion of the effluent and apply the above methods only to the diverted flow, the resulting measurements may suffer from reduced sensitivity due to the small sample size. In light of the above, there is a need for a robust and efficient system and method for detecting radical concentrations in particle streams generated for semiconductor processing. Outline: Embodiments of the present invention were devised and developed with the aim of providing solutions to the above-mentioned objective technical needs, as will be demonstrated in the following description. One embodiment can be generally characterized as a system for determining the concentration of radicals in a particle stream delivered into a semiconductor processing chamber. The system comprises a plasma generator having an inlet configured to receive an outflow of a particle stream containing radicals and diluent gases, wherein the plasma source is operable to generate a glow discharge for exciting radicals and diluent gases in the received outflow; a spectrometer optically coupled to the internal glow discharge region of the plasma generator and operable to output measurement data representing the intensity of light emitted by the radicals and diluent gases; and a controller communicatively coupled to the spectrometer and operable to calculate the concentration of radicals in the outflow based on the measurement data. Another embodiment can be generally characterized as a particle flow delivery system used with a semiconductor processing chamber, the system comprising: a remote plasma source operable to generate an outflow of particles containing radicals and diluent gases; a plasma generator having an inlet configured to receive the outflow and an outlet configured to be coupled to a semiconductor processing chamber, wherein the plasma source is operable to generate a glow discharge for exciting radicals and diluent gases in the outflow and to deliver the outflow to the semiconductor processing chamber; a light-shielding feature positioned between the remote plasma source and the plasma generator, the light-shielding feature configured to deliver the outflow but prevent light emitted from the remote plasma source from reaching the plasma generator; a spectrometer optically coupled to the internal glow discharge region of the plasma source and operable to output measurement data representing the intensity of light emitted by radicals and diluent gases; and a controller communicatively coupled to the spectrometer and operable to calculate the concentration of radicals in the outflow based on the measurement data. Brief Description of the Drawings The above and other aspects, features and advantages of the present invention will become more appar