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采用常规 PECVD工艺 ,以高纯 H2 稀释的 Si H4 作为反应气体源 ,以 PH3作为 P原子的掺杂剂 ,在 P型 ( 1 0 0 )单晶硅 ( c- Si)衬底上 ,成功地生长了掺 P的纳米硅膜 ( nc- Si( P)∶ H)膜 .通过对膜层结构的 Raman谱分析和高分辨率电子显微镜 ( HREM)观测指出 :与本征 nc- Si∶H膜相比 ,nc- Si( P)∶ H膜中的 Si微晶粒尺寸更小 (～ 3nm) ,其排布更有秩序 ,呈现出类自组织生长的一些特点 .膜层电学特性的研究证实 ,nc- Si( P)∶ H膜具有比本征 nc- Si∶ H膜约高两个数量级的电导率 ,其 σ值可高达 1 0 - 1～ 1 0 - 1Ω- 1· cm- 1.这种高电导率来源于 nc- Si( P)∶H膜中有效电子浓度 ne的增加、Si微晶粒尺寸的减小和电导激活能 ΔE的降低 .采用 nc- Si( P)∶H膜和 P型 c- Si制备了异质结二极管 ,其反向击穿电压值可高达 75V,而反向漏电流却仅有几个 n A,呈现出良好的反向击穿特性
Using a conventional PECVD process, Si H4 diluted with high-purity H2 as a source of reaction gas and PH3 as a dopant of P-atom were successfully deposited on a P-type (100) single-crystal silicon (Nc-Si (P): H) films doped with P were grown by Raman spectroscopy and high resolution electron microscopy (HREM) In contrast, the Si microcrystalline grains in the nc-Si (P): H film are smaller in size (~3 nm) and their arrangement is more orderly and show some characteristics of self-organized growth. Studies on the electrical properties of the film confirmed The nc-Si (P): H film has an electrical conductivity about two orders of magnitude higher than that of the intrinsic nc-Si: H film, with σ values as high as 10 -1 to 10 Ω -1 cm -1. This high electrical conductivity is derived from the increase of the effective electron concentration ne in the nc-Si (P): H film, the decrease of Si microcrystalline size and the decrease of the conductance activation energy ΔE. And P-type c-Si heterojunction diodes were prepared, the reverse breakdown voltage can be as high as 75V, while the reverse leakage current is only a few nA, showing good reverse breakdown characteristics