Gas flow process control system and method using crystal microbalance(s)

Abstract

The invention relates to a gas flow process control system and a method using crystal microbalance(s). Disclosed are process control systems and methods incorporating a crystal microbalance (CM) (e.g., a quartz crystal microbalance (QCM)) into gas flow line(s) entering and / or exiting a processing chamber. A CM measures the resonance of a quartz crystal sensor contained therein as gas flows over that crystal sensor and can, thereby be used to accurately monitor, in real time, the mass flow rate of the gas. The mass flow rate may indicate that gas contamination has occurred and, in response, a controller can cause the gas flow to stop. Additionally, the mass flow rate may indicate the desired result will not be achieved within the processing chamber and, in response, advanced process control(APC) can be performed (e.g., the controller can adjust the gas flow). CM(s) incorporated into gas flow lines entering and / or exiting a processing chamber can provide precise measurements for processmonitoring at minimal cost.

Description

technical field [0001] The present invention relates to process control systems and methods, and more particularly to gas flow process control systems and methods. Background technique [0002] In integrated circuit (IC) manufacturing and other industries, processes requiring the use of one or more gases within a process chamber are typically very sensitive to variations in gas properties including composition and / or concentration. For example, atomic layer deposition (ALD) and atomic layer etching (ALE) processes use process chambers to deposit atomic layers of materials onto and etch away atomic layers of materials from semiconductor wafers, respectively. During processing (ie, during ALD or ALE), a first gas and a second gas (also referred to as a precursor) are sequentially pulsed into the processing chamber and purged from the processing chamber between each of the pulses. By repeatedly exposing the surface of the semiconductor wafer within the processing chamber to th...

AI Technical Summary

Problems solved by technology

However, current APC techniques may not be sufficiently precise and / or may not be cost-effective

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