Calorimetric investigation of relaxation processes in disordered semiconductors

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:527699

Budaguan, B G; Aivazov, A A; Sazonov, A Yu ^[1]

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1. Moscow Inst. of Electronic Technology (Russian Federation). Dept. of Microtechnology

The comparative study of relaxation processes in amorphous hydrogenated (a-Si:H) and porous silicon (PS) by use of differential scanning calorimetry (DSC) measurements is presented. Films of a-Si:H were deposited by RF glow discharge of two gas mixtures (10% SiH{sub 4} + 90% H{sub 2}) and (5% SiH{sub 4} + 95% He). PS films have been prepared by electrochemical etching of 1{Omega}{center_dot}cm (p- PS) and of 0.01{Omega}{center_dot}cm (p+ PS) p-type Si substrates. The DSC traces were recorded during the heating of samples at a constant rate of 10 C/min from 20 to 570 C in an Ar atmosphere. All investigated samples present a low temperature exothermic effect with a maxima within 120--280 V. At higher temperatures (T > 300 C) a second exothermic effect is observed for a-Si:H films prepared from both hydrogen and helium diluted silane mixtures while two endothermic effects are observed for PS samples. Analysis of the low temperature exothermic effects has been performed, and focused on the relaxation of weak Si-Si bonds which are the features of both amorphous hydrogenated and porous silicon. It was shown that the endothermic effect connected with hydrogen effusion from PS at higher temperatures is compensated by exothermic structural rearrangement in the case of a-Si:H.

• OSTI ID: 527699
• Report Number(s): CONF-960401--; ISBN 1-55899-323-1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALORIMETRY
CHEMICAL BONDS
CHEMICAL VAPOR DEPOSITION
EXPERIMENTAL DATA
HEAT FLUX
HEATING RATE
MICROSTRUCTURE
RELAXATION
SAMPLE PREPARATION
SILICON