Thermocouple for semiconductor heater

Thu, 02 Jul 2026 03:50:01 +0800

On the fab floor, a 0.5°C drift in bake temperature will move critical dimensions and turn a whole lot of wafers into scrap. Semiconductor heating doesn’t forgive much. Photoresist soft bake and hard bake need repeatable setpoints—same across every slot, same every shift. We built our thermocouple for that reality. What matters under the hood We run a Type K thermocouple with a low-thermal-mass junction and an oxidation-resistant sheath. Response stays under 200 ms, and it holds steady at 500°C, continuous. The controller linearizes the output, and the probe geometry matches the heater profile so we’re measuring the wafer plane, not the heater block. Wafer-level uniformity lands within ±0.1°C, with low self-heating and negligible EMF drift. The assembly is rated for Class 1–100 cleanrooms, and the materials and joints don’t shed particles or outgas. Why this works where we work In lithography tracks and coat/bake modules, this thermocouple closes the thermal loop. You keep photoresist bake profiles on spec, cut rework, and tighten thermal budget control. The payoff is fewer excursions, stable CDs, and yield you can count on. Energy use drops because the heater hits the exact setpoint—no overshoot. Reliability stacks up over tens of thousands of thermal cycles, which translates into fewer maintenance calls and less unplanned downtime. The details that bite you if you ignore them Mounting tolerance is tight. The probe tip has to sit right in the designed thermal node if you want the stated uniformity. Swapping into legacy heater blocks usually needs a bit of controller tuning—thermal mass changes, so the loop responds differently. Keep the sheath intact. Bend it or over-torque the fitting, and you’ll drift calibration. Plan drift checks at your PM intervals. Even the best thermocouple ages, and in semiconductor, we plan for that.

Thermocouple on Warm IR Heating Equipment

Thermocouple for semiconductor heater