Applying Virtual Metrology of Advanced Process Control in Predicting Wavelength of LED Epitaxy Process
Lin, Hsien Hsiang
|關鍵字:||LED;磊晶;先進製程控制;虛擬量測;決策樹;類神經網路;最近鄰居法;LED;Epitaxy;APC;Virtual Metrology;Decision Tree;ANN;kNN|
The Epitaxy is the primary process of LED, in which the stability of Epitaxy may affect the quality of end production, capacity of factory and market share. The result of wavelength measurement is the criteria to make sure the Epitaxy process is successful or not. Once the measuring result is too far away from the target wavelength, it implies that process controlling ability of the Epitaxy tool needs to be tuned, or some human errors need to be corrected for increasing the stability of Epitaxy tool. Consequently, the wavelength measurement is important over the LED manufacturing process. Wavelength measurement is often interrupted because of human errors and the crashes of measurement tool, which leads to the decline of the tool utilization ratio. This research proposes to apply virtual metrology to predict wavelength of LED Epitaxy Process based the Advanced Process Control (APC) in semiconductor industry. This research compares three virtual metrology methods, including Decision Tree, ANN and kNN methods, and evaluates their effectiveness in predicting the wavelength of LED Epitaxy process. The proposed virtual metrology can shorten the waiting time of the batches for wavelength measurement, respond feedback information rapidly, raise utilization ratio of production and reduce manufacturing cost.
|Appears in Collections:||Thesis|