本研究開發一套晶圓製程參數量測系統，用於即時監控MOCVD製程中，晶圓表面溫度、薄膜沉積成長率與折射率。開發的系統整合了薄膜成長率量測模組與溫度量測模組，基於薄膜光學理論進行薄膜成長率量測，藉由薄膜反射率歷時曲線與開發演算法，計算出薄膜成長率與折射率；基於普朗克黑體輻射理論與克希荷夫定理進行溫度量測，藉由反射率補償發射率，修正量測溫度值。 設計空氣膜實驗與旋轉塗佈實驗，驗證本系統在薄膜成長率量測的能力。空氣膜實驗中，使用楔形稜鏡與壓電陶瓷位移平台模擬薄膜成長情形；旋轉塗佈實驗中，量測光阻附著於晶圓上的厚度變化量。將量測結果與商用膜厚儀進行比較，差量低於2%。 在溫度量測模組，設計在真空加熱腔體內進行實驗，驗證接收940 nm波段與400 nm波段的熱輻射訊號對於晶圓溫度量測的能力，並使用反射率變化，即時修正量測溫度。系統量測範圍於450 ℃以上，系統能穩定的量測到溫度。於低溫段450 ℃時，與商用量測系統溫度差量約為4 ℃；高溫段750 ℃以上時，與商用量測系統溫度差量約為0.5 ℃。 ;An in-situ monitoring system for Metal Organic Chemical Vapor Deposition (MOCVD) process is presented. The proposed monitoring system consisted of the modules of growth-rate and temperature, which is able to precisely measure the growth rate of thin film and the surface temperature of wafer in the MOCVD process. The principles of monitoring system are based on the thin film interference theorem and the blackbody radiation. In our system, the detector received the reflectance variation of thin film and the thermal radiation of wafer, while a lock-in amplifier was used to demodulate the reflected light of laser source and the thermal radiation signal. According to the thin film interference theorem and Kirchhoff’s law, the thin film growth rate and compensated temperature can be obtained. To demonstrate the feasibility of the growth-rate module, we designed an air layer that can change its thickness by using a piezoelectric (PZT) actuator. We also implemented the photoresist spin coating on a silicon wafer experiment to verify the measurement ability. To demonstrate the feasibility of the temperature measurement module, the 940 nm and 400 nm band of the thermal radiation resulting from the surface of the heated silicon wafer was received by the temperature module and used to determine the surface temperature of the wafer. The experimental results demonstrate that the growth rate, optical constants of the film, and temperature of wafer surface could be precisely determined in real time. Comparing the measurement results obtained using our proposed system with the ones obtained by the commercial metrology equipment (surface profiler and pyrometer), the relative differences are less than 2%.
