The role of hydrogen in the formation of microcrystalline silicon

Abstract

Abstract:The growth mechanisms of microcrystalline films at low temperatures (100-250°C) by plasma CVD are still a matter of debate. We have shown that µc-Si:H formation proceeds through four phases (incubation, nucleation, growth and steady state) and that hydrogen plays a key role in this process, particularly during the incubation phase in which hydrogen modifies the amorphous silicon network and forms a highly porous phase where nucleation takes place. In this study we combine in-situ ellipsometry and dark conductivity measurements with ex-situ high resolution transmission electron microscopy to improve our understanding on microcrystalline silicon formation.

Nanocrystalline silicon TFT process using silane diluted in argon–hydrogen mixtures

“…3(a). As expected [13], the 25 nm thin films reveal a dominant amorphous structure with a weakly crystallized phase (F c % 48%). When the growth process is performed with pure H 2 -diluted SiH 4 plasma, the crystalline fraction F c increases progressively with the film thickness up to a steady state of F c = 70%.…”

Undoped and arsenic-doped low temperature (∼165°C) microcrystalline silicon for electronic devices process

“…2. As expected [5], with only highly H 2 -diluted SiH 4 plasma, the 20 nm thin films reveal a dominant amorphous structure with a weakly crystallized phase. Not well-defined lc-Si grains with irregular shapes are poorly distributed, leading to an heterogeneous morphology of the deposited layers.…”

Gallium assisted plasma enhanced chemical vapor deposition of silicon nanowires

“…In (b) the plasma was stopped for 10 min, while in (c) there was no interruption between plasma annealing and growth. diluted silane plasmas lead to the formation of microcrystalline silicon or thin films with nanocrystalline inclusions [42,43]. Thin film grown under the plasma conditions used in this paper would lead to a growth rate of 1.3 nm min −1 .…”