Title :
Real-time Optical Thickness Monitor for thin film growth
Author :
Zeller, R.M. ; Walker, J.D. ; Wieland, K.A. ; Compaan, A.D.
Author_Institution :
Dept. of Phys. & Astron., Univ. of Toledo, Toledo, OH, USA
Abstract :
In order to achieve maximum efficiency and performance in a photovoltaic solar cell module, the precise thickness of the semiconductor layers must be controlled. An Optical Thickness Monitor (OTM) based on optical interference can be used to better understand and to monitor the deposition process in real time. The OTM utilizes laser light either in transmission mode or in reflection mode which is detected with a photodiode. By measuring the interference fringes produced, the OTM displays real-time film thickness and material growth rate. Predicted film thicknesses are in good agreement with measured values.
Keywords :
II-VI semiconductors; cadmium compounds; laser modes; light interference; light interferometry; measurement by laser beam; moire fringes; semiconductor growth; semiconductor thin films; sputter deposition; thickness measurement; CdS; CdTe; OTM; deposition process; interference fringes; laser light; material growth rate; optical interference; photodiode; photovoltaic solar cell module; real-time film thickness; real-time optical thickness monitor; reflection mode; rf magnetron sputtering; semiconductor layers; transmission mode; Interference; Monitoring; Optical control; Optical films; Photovoltaic cells; Photovoltaic systems; Semiconductor thin films; Solar power generation; Thickness control; Thickness measurement;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2009 34th IEEE
Conference_Location :
Philadelphia, PA
Print_ISBN :
978-1-4244-2949-3
Electronic_ISBN :
0160-8371
DOI :
10.1109/PVSC.2009.5411297
