Unconsumed precursor monitoring

Inventors

Rinzan, Mohamed Buhary • Song, Chunhua • Lakeman, Steve James

Assignees

Inficon Inc

Abstract

A monitoring device for monitoring a fabrication process in a fabrication system. The monitored fabrication system includes a process chamber and a plurality of flow components. A quartz crystal microbalance (QCM) sensor monitors one flow component of the plurality of flow components of the fabrication system and is configured for exposure to a process chemistry in the one flow component during the fabrication process. A controller measures resonance frequency shifts of the QCM sensor due to interactions between the QCM sensor and the process chemistry in the one flow component during the fabrication process. The controller determines a parameter of the fabrication process in the process chamber as a function of the measured resonance frequency shifts of the QCM sensor within the one flow component.

Core Innovation

The patent describes a monitoring device for monitoring a fabrication process in a process chamber of a fabrication system that applies a first material to a substrate using a plurality of flow components. The monitoring device includes a quartz crystal microbalance (QCM) sensor configured for exposure to process chemistry in one flow component during the fabrication process, and the QCM sensor comprises a material layer including at least in part the first material accumulated on the QCM sensor in situ during the fabrication process in the process chamber.

A controller measures resonance frequency shifts of the QCM sensor due to interactions between the accumulated material layer on the QCM sensor and the process chemistry in the one flow component during the fabrication process. The controller determines a parameter of the fabrication process in the process chamber as a function of the measured resonance frequency shifts of the QCM sensor. The approach is extended to monitoring an exhaust line or a supply line of the plurality of flow components, where the resonance frequency shifts correspond to interactions with process chemistry including a precursor gas.

The document further characterizes embodiments in which the QCM sensor interacts with a material layer accumulated in situ and, in particular cases, uses a getter material layer. In such cases, the controller uses the resonance frequency shifts associated with changing mass of the getter material due to interactions with process chemistry to determine a process chamber condition such as an air leak. The patent also describes controlling or limiting QCM exposure, including use of an apparatus for limiting exposure and variants involving controlled temperature or differential multi-QCM checking.

Claims Coverage

The document provides three independent claim scopes, each based on measuring QCM resonance frequency shifts and determining a fabrication process parameter in the process chamber. The independent claims collectively specify three inventive features centered on the in situ accumulated material layer on the QCM sensor, the resonance frequency shift measurement due to interactions with process chemistry, and the derived process parameter or condition.

Across the independent claims, the common claim coverage centers on a QCM sensor with an in situ accumulated material layer exposed to process chemistry in a selected flow component, measuring QCM resonance frequency shifts caused by interactions with that accumulated material layer, and determining a parameter of the fabrication process in the process chamber based on the measured resonance frequency shifts.

Stated Advantages

Documented Applications