Title :
Photoreflectance characterization of graded emitter InAlGaAs/InGaAs HBTs
Author :
Wojtowicz, Mike ; Block, T. ; Pascua, D. ; Han, A.C. ; Streit, D.
Author_Institution :
Electron. & Technol. Div., TRW Inc., Redondo Beach, CA, USA
Abstract :
We have measured the photoreflectance spectra from the emitter region of In0.53(AlxGa1-x)0.47 As (0.3<x<1.0) graded emitter InGaAs/InAlGaAs HBTs grown by MBE on InP substrates. From the Franz-Keldysh oscillations we have determined the built-in dc electric fields and energy gaps which were then compared to modeled results. Features were identified corresponding to the uniform InAlAs layer as well as the graded layer and good agreement between the modeled and experimental results was obtained. A feature originating in the graded emitter region has been identified and correlated to base dopant diffusion into the emitter
Keywords :
III-V semiconductors; aluminium compounds; energy gap; gallium arsenide; heterojunction bipolar transistors; indium compounds; photoreflectance; reflectivity; Franz-Keldysh oscillations; InAlGaAs-InGaAs; InP substrate; MBE; base dopant diffusion; built-in DC electric field; energy gap; graded emitter InAlGaAs/InGaAs HBT; photoreflectance spectra; Electrostatics; Heterojunction bipolar transistors; Indium compounds; Indium gallium arsenide; Indium phosphide; Molecular beam epitaxial growth; Monitoring; Photonic band gap; Semiconductor process modeling; Substrates;
Conference_Titel :
Indium Phosphide and Related Materials, 1996. IPRM '96., Eighth International Conference on
Conference_Location :
Schwabisch-Gmund
Print_ISBN :
0-7803-3283-0
DOI :
10.1109/ICIPRM.1996.492313
