Structural and Electrical Properties of Undoped Microcrystalline Silicon Grown by 70 MHz and 13.56 MHz PECVD

ABSTRACTMicrocrystalline silicon films deposited by plasma methods have an optical absorption for photon energies above 2.0 eV lower than a-Si:H films and can be efficiently doped with boron or phosphorus. The most widely used deposition technique is the 13.56 MHz PECVD. However quite recently µc-Si:H films were grown at high deposition rates by the 70 MHz PECVD. In this work the authors report on a comparison between µc-Si:H films deposited by both 70 MHz and 13.56 MHz techniques. Particular attention has been devoted to differences and similarities between structural, compositional and electrical properties of the films deposited with the two systems.