Real-time monitoring and control during MBE growth of GaAs/AlGaAs Bragg reflectors using multiwave ellipsometry

Thomas Wagner; Blaine D. Johs; Craig M. Herzinger; Ping He; Shakil Pittal; John A. Woollam

doi:10.1117/12.271830

1 April 1997 Real-time monitoring and control during MBE growth of GaAs/AlGaAs Bragg reflectors using multiwave ellipsometry

Thomas Wagner, Blaine D. Johs, Craig M. Herzinger, Ping He, Shakil Pittal, John A. Woollam

Author Affiliations +

Proceedings Volume 3094, Polarimetry and Ellipsometry; (1997) https://doi.org/10.1117/12.271830
Event: Polarimetry and Ellipsometry, 1996, Kazimierz Dolny, Poland

Abstract

New multi-wavelength in-situ ellipsometer acquiring accurate ellipsometric data at 44 wavelength form 415 to 750 nm in less than 1s is directly mounted on a MBE growth system. Compared to single wavelength ellipsometers enough measured data are available to have access to layer thickness, composition, temperature and exact angle of incidence. In- situ monitoring and real time analysis was used to control the process of GaAs/AlGaAs Bragg reflectors with center wavelength of 1000 nm. The layer thickness is controlled very accurately even though ellipsometric data was acquired only every 3 seconds. The accuracy of shutter timing can be made very precisely even for slow ellipsometric acquisition rates and substrate wobble due to MBE substrate rotation. The control algorithm for two reflectors did not attempt to control the Al composition of an individual AlGaAs layer, but the measured composition was used to adjust the Al cell temperature for the next AlGaAs layer. In comparison for another reflector, the FastDyn fitting routine were used to simultaneously control the thickness and surface composition of the AlGaAs layers. An overview about the hardware and software integration on the MBE system will be given. The in-situ measurements during the growth control were later compared with ex-situ measurements made with spectroscopic ellipsometer system VASE.

Citation Download Citation

Thomas Wagner, Blaine D. Johs, Craig M. Herzinger, Ping He, Shakil Pittal, and John A. Woollam "Real-time monitoring and control during MBE growth of GaAs/AlGaAs Bragg reflectors using multiwave ellipsometry", Proc. SPIE 3094, Polarimetry and Ellipsometry, (1 April 1997); https://doi.org/10.1117/12.271830

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available