Hydrogen incorporation in silicon thin films deposited with a remote hydrogen plasma

Abstract

Results are presented on the effects of growth conditions on hydrogen incorporation in Si thin films deposited with a remote hydrogen plasma. Oxygen contamination of the films was significantly reduced by replacement of the quartz tube that is commonly used to contain the hydrogen plasma with an alumina tube, with a concomitant increase in the electrical conductivity of P-doped a-Si:H films. Hydrogen incorporation was examined with a remote deuterium plasma and downstream injection of SiH4. As the gas flow ratio D2:SiH4 increases, the ratio D:H in the film changes as a consequence of the increasing flux of D at the growing surface. High silane dilution also promotes the formation of microcrystalline silicon, which itself affects H incorporation.

Deposition of a-Ge:H in a Remote Plasma System

“…From the 1/Itr products the gap defect density can be estimated, giving values between lx101 7 and 2x10 1 8 cm-3 . Our findings for a-Ge:H is however quite different from a-Si:H remote deposition [2,5] in two aspects: There is no marked enhancement of the film quality at low Td, and purely amorphous Ge:H with the highest photoconductivity are obtained with H 2 as a carrier gas, which tends to give a mixed amorphous / microcrystalline phase for silicon deposition [3,4]. /Ic-phase has not been seen in a-Ge:H by Raman spectroscopy at H 2 /GeH 4 = 100/2.…”

“…A remote plasma reactor was designed providing deposition parameters similar to those described in the literature [2,3], at the same time facilitating spectroscopic observations.…”

“…In particular the remote deposition of a-Si:H has received considerable attention [2,3,4,5]. The technique proved to be quite promising since good material can be obtained at much lower deposition temperatures down to 1000C than in direct plasma CVD.…”

Studies of the Plasma Related Oxygen Contamination of Gallium Nitride Grown by Remote Plasma Enhanced Chemical Vapour Deposition

“…Fused alumina ia a potential alternative. Oxygen is more strongly bound for alumina than for quartz, Johnson et al [4] have observed a significant reduction in oxygen contamination of silicon films when using a remote hydrogen plasma contained in alumina rather than quartz.…”

Investigation of native oxide removing from HCPA ALD grown GaN thin films surface utilizing HF solutions

“…Additionally, this pollution can be addressed with gas purifiers, and by improving the vacuum system with the use of load locks, adequate attention to system leaks and having a good quality pumping system. Substituting alumina tubes for quartz can lead to some improvement [20]. Thus, our main goals is to understand: (1) how could we efficiently remove native oxide from the surface of III-nitride thin films grown using hollow cathode plasma assisted ALD; (2) how and for how long could we protect the film surfaces from oxidation for the next steps of device fabrication.…”