Wide Spectrum Monitoring The Development Of Thin Film Growth System

Film thickness is one of the most important parameters during the process of film coating.The film coating technology is to study how to control each film thickness during the coating process.The film coating technology has been developed for more than one hundred years.Many thin film monitoring methods had been developed,for example,photo-electricity measurement,wavelength modulation,polarization analysis,quartz-crystal oscillation,single wavelength monitoring,and broadband optical monitoring(BOM),and so on.Broadband optical monitoring technique has become more and more popular due to its higher efficiency than other techniques and can precisely control film coating process at any thickness[1-12].The purpose of this paper is to study the broadband optical monitoring system applied to the film growth process.First of all,this paper gives a historic review of the film coating process,and introduces some techniques such as the film deposition and monitoring that are widely used in the academic and industry fields nowadays.Then,the theory and structure of BOM are presented in detail,including the data sampling,noise reduction,and software system control,and so on.An advanced spectrometer with high spectral resolution and fast acquisition time is used in the BOM system to measure in-situ the spectra of thin films during deposition process,and can also monitor the properties of the narrow band-pass filter used widely in modern communication field.The system control software has been developed based on VC++6.0 environment.Furthermore, the algorithms of noise reduction and deposition stop criteria also have been given in the paper.