Out on the lithography floor, you know how it goes. A 0.1°C drift in bake temperature shifts the photoresist profile by nanometers, and that shift shows up on the yield sheet. We built our semiconductor laser diode heaters to hold the thermal line when the process window is measured in single-digit nanometers. What matters under the hood We use near-infrared (NIR) laser diode heating with closed-loop control, and the uniformity across the active area stays within ±0.1°C. Repeatability holds at ±0.2°C shot-to-shot, so soft bake and hard bake profiles don’t drift from the first lot to the hundredth. The platform runs clean—zero particle generation under Class 1–100 conditions—and it stays up 24/7 without unplanned downtime. Response is quick, so thermal lag between recipe steps is minimal, and you don’t burn extra thermal budget on sensitive films. Why this matters in photoresist processing Bake energy is what drives CD control, sidewall angle, and defect density. With these heaters, the substrate sits at the target setpoint with very little overshoot, so you get tighter CD distributions and fewer rework lots. The stability cuts scrap and rework, shortens changeover, and keeps energy use following the process curve. You get more predictable output in the same footprint, without chasing temperature excursions after tool shifts. Here’s what to expect on the install These heaters are designed to drop into existing coat/bake tracks, but you need matched interfaces and calibrated sensors to hold that ±0.1°C uniformity. Commissioning is quick—align the optical path and tune the control loop for your substrate stack. After that, it’s routine checks: verify sensor calibration and keep the optics clean, same as any other day in the cleanroom.