Patent ID: 9716022
Date: 2017-07-25
CPC Classifications: G05B,H01L

Claim:
1. A method of determining thermal stability of an upper surface of a substrate support assembly in a plasma processing apparatus wherein the substrate support assembly includes an array of electrical heaters that form independently controllable heater zones of the substrate support assembly, and wherein the array of electrical heaters are operable to control the spatial and temporal temperature of the upper surface of the substrate support assembly, the method comprising: recording time resolved pre-process temperature data of the substrate support assembly before performing a plasma processing process while powering the array of electrical heaters to achieve a desired spatial and temporal temperature of the upper surface of the substrate support assembly, wherein the electrical heaters generate heat when powered; processing a substrate or a batch of substrates in the plasma processing apparatus while powering the array of electrical heaters to achieve a desired processing spatial and temporal temperature of the upper surface of the substrate support assembly; recording time resolved post-process temperature data of the substrate support assembly after processing the substrate or the batch of substrates while powering the array of electrical heaters to achieve the desired spatial and temporal temperature of the upper surface of the substrate support assembly; comparing the post-process temperature data to the pre-process temperature data; and determining if the post-process temperature data is within a desired tolerance range of the pre-process temperature data.