Title :
New regime of RF PECVD for the growth of a-Si:H and its alloys with improved electronic properties
Author :
Middya, A.R. ; Hazra, S. ; Ray, S. ; Longeaud, C. ; Kleider, J.P.
Author_Institution :
Thin Film Div., Solarex Corp., Newtown, PA, USA
fDate :
29 Sep-3 Oct 1997
Abstract :
a-Si:H and its alloy developed under a `new regime´ (α-γ´ transition zone) of discharge of RFPECVD and using strong helium dilution show lots of new characteristics. The value of μτ of the resulting films is enhanced by a factor of 10 to 100 (independent of Fermi level position) and concomitantly the DOS above Fermi level of a-Si:H and a-SiGe:H ([Ge]⩽0.20) is much lower than that of standard samples. The carrier mobility measured by time resolved microwave conductivity (TRMC) is increased by a factor of 2 to 3. HRTEM micrograph shows the region of ordered structure (nanocrystal) embedded in an amorphous matrix. The reproducibility of this type of materials in different reactors has been confirmed. Thus, inclusion of ordered network structure in the amorphous matrix could be the new way to improve electronic properties of a-Si:H and its alloys
Keywords :
Ge-Si alloys; amorphous semiconductors; carrier mobility; electronic density of states; elemental semiconductors; high-frequency effects; hydrogen; plasma CVD coatings; semiconductor growth; semiconductor thin films; silicon; α-γ´ transition zone; μτ values; HRTEM micrograph; RF PECVD; Si:H; SiGe:H; a-Si:H growth; a-SiGe:H; amorphous matrix; carrier mobility measurement; density of states; electronic properties; nanocrystal; ordered structure; strong helium dilution; time resolved microwave conductivity; Amorphous materials; Conducting materials; Conductivity measurement; Helium; Inductors; Microwave measurements; Nanocrystals; Radio frequency; Reproducibility of results; Time measurement;
Conference_Titel :
Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE
Conference_Location :
Anaheim, CA
Print_ISBN :
0-7803-3767-0
DOI :
10.1109/PVSC.1997.654174
