Dependence of the a-Si:H defect density of states on the magnetic field profile of an electron cyclotron resonance microwave plasma

1994 ◽  
Vol 240 (1-2) ◽  
pp. 152-156 ◽  
Author(s):  
F.S Pool ◽  
J.M Essick ◽  
Y.H Shing ◽  
R.T Mather
Keyword(s):  
Magnetic Field ◽  
Density Of States ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Defect Density ◽  
Field Profile ◽  
Magnetic Field Profile ◽  
The Magnetic Field ◽  
Resonance Microwave

Dependence of the a-Si:H Defect Density of States on the Magnetic Field Profile of an Electron Cyclotron Resonance Microwave Plasma

1992 ◽  
Vol 258 ◽  
Author(s):  
F.S. Pool ◽  
J.M. Essick ◽  
Y.H. Shing ◽  
R.T. Mather
Keyword(s):  
Magnetic Field ◽  
Density Of States ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Defect Density ◽  
Electron Cyclotron ◽  
Field Profile ◽  
Magnetic Field Profile ◽  
The Magnetic Field

ABSTRACTThe magnetic field profile of an electron cyclotron resonance (ECR) microwave plasma was systematically altered to determine subsequent effects on a-Si:H film quality. Films of a-Si:H were deposited at pressures of 0.7 mTorr and 5 mTorr with a H2/SiH4 ratio of approximately three. The mobility gap density of states ND, deposition rate and light to dark conductivity were determined for the a-Si:H films. This data was correlated to the magnetic field profile of the plasma, which was characterized by Langmuir probe measurements of the ion current density. By variation of the magnetic field profile ND could be altered by more than an order of magnitude, from 1×1016 to 1×1017 at 0.7 mTorr and 1×1016 to 5×1017 at 5 mTorr. Two deposition regimes were found to occur for the conditions of this study. Highly divergent magnetic fields resulted in poor quality a-Si:H, while for magnetic field profiles defining a more highly confined plasma, the a-Si:H was of device quality and relatively independent of the magnetic field configuration.

Characterization of Electron Cyclotron Resonance Plasma-Deposited Hydrogenated Amorphous Silicon and Related Alloy Films

1991 ◽  
Vol 219 ◽  
Author(s):  
J. M. Essick ◽  
F. S. Pool ◽  
Y. H. Shing ◽  
M. J. Holboke
Keyword(s):  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Defect Density ◽  
Growth Conditions ◽  
Electron Cyclotron ◽  
Dc Conductivity ◽  
Rf Plasma ◽  
Plasma Enhanced Cvd ◽  
Magnetic Field Profile

ABSTRACTWe characterized a-Si:H films deposited by the electron cyclotron resonance (ECR) microwave plasma-enhanced CVD technique with the purpose of comparing ECR film quality widi that of films deposited by the rf plasma-enhanced CVD method. These ECR films were deposited in the 1–10 mT pressure region under a variety of growth conditions. Our investigations reveal the following typical properties for intrinsic ECR-deposited a-Si:H: (1) high photosensitivity as indicated by a light-to-dark DC conductivity ratio of up to 2×106, (2) a Tauc gap in the range of 1.75–1.85 eV, (3) an Urbach slope of 45–60 meV as determined by CPM and (4) an integrated deep defect density of 0.5–2×1016 cm-3 with Ec - Ef = 0.74–0.87 eV as determined by drive level profiling and junction capacitance vs. temperature scans. Variations of these quantities with deposition temperature, hydrogen dilution and magnetic field profile are discussed. Our results indicate that ECR-deposited a-Si:H is of comparable quality to a-Si:H deposited by the rf plasma glow discharge technique. ECR deposition conditions for a highly conductive type of a-Si:H film also are discussed. This material, while only slightly photosensitive and possessing an Urbach slope of over 100 meV, has a light DC conductivity of 3×10-4 (Ωcm)-1. Boron doping of this material produces a conductivity of 5×10-2 (Ωcm)-1.

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