Precision Thermocouple Amplifier for Substrate Temperature Monitoring in an ECR-PE Nano-Film Deposition System

The measurement of high temperature beyond 200deg C are usually carried out by optical pyrometer, but for laboratory applications thermocouples are widely used. Various types of thermocouples are available for different temperature ranges. Their sensitivities are below 100 micro Volt/deg C. The precision low noise amplifiers are essential for the inputs of the microcontrollers. In this study a thermocouple amplifier has been developed based on LTC2053, zero drift, rail to rail, instrumentation amplifier. The zero drift characteristics of the developed amplifier provides better accuracy and reliability. The rail to rail feature expands the working range for a given supply voltage. This amplifier circuit is used to precisely monitor the temperature of a substrate placed inside a 2.45 GHz high vacuum Electron Cyclotron Resonance Plasma Enhanced (ECR-PE) nano film deposition system.