New two-step growth of microcrystalline silicon thin films without incubation layer

A new two-step growth method was proposed to fabricate microcrystalline silicon (μc-Si:H) thin films by an electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD). An ultra thin Si film was first deposited and followed by H2 plasma treatment for few minutes, and then the μc-Si:H film was deposited on it. High-resolution transmission electron microscope (HRTEM) and Raman spectrometer were used to study the microstructures and the crystalline volume fraction of μc-Si:H films. The HRTEM results show that the amorphous silicon thin film with a thickness of 15 nm can be crystallized by H2 plasma treatment in 2 min, and then it serves as the seed layer for the subsequent growth of μc-Si:H films. By optimizing the deposition parameters, the μc-Si:H film without amorphous incubation layer can be fabricated by this new two-step method and a proper crystalline volume fraction of 50.6% can be obtained.