PARAMETERS CONTROLLING THE DEPOSITION OF AMORPHOUS AND MICROCRYSTALLINE SILICON IN Si/H DISCHARGE PLASMAS (original) (raw)

Plasma deposition of amorphous silicon films: an overview on some open questions

Pure and Applied Chemistry, 2000

Results on amorphous silicon deposition by SiH SiF and Sic1 glow discharges are discussed so as to better understand the plasma phase processes leading to the growth precursors, the plasma/surface interaction and the microscopic parameters affecting the material properties. In particular, the chemical activity of both silicon radicals, hydrogen and halogen atoms, as well as charged particles in the gas phase and on the surface is examined.

From Amorphous to Microcrystalline Silicon: Moving From One to the Other by Halogenated Silicon Plasma Chemistry

Philosophical …, 2009

Amorphous and microcrystalline silicon thin films have been deposited on a large variety of substrates including crystalline silicon, Corning glass and polyimide exploiting SiF 4-H 2-He radiofrequency (13.56 MHz) plasma enhanced chemical vapor deposition. Spectroscopic ellipsometry has been mainly applied to investigate the optical and structural characteristics of the deposited films and to investigate the microstructure depending on the experimental parameters, including the H 2 and He dilution of plasmas, the deposition temperature, and the substrate plasma treatment prior to deposition. The film growth dynamics has also been investigated by analyzing films with different thickness. The peculiarities of the SiF 4 chemistry involved in heterogeneous processes during film deposition and responsible for the amorphous to micro-crystalline transition are presented. It is demonstrated that the SiF 4-H 2 chemistry leads to tailoring of film microstructure from amorphous to fully and dense microcrystalline silicon films without any amorphous incubation layer also at temperature as low as 100°C on any substrate, including Corning glass 7059 and polyimide, independently of film thickness. These results and peculiarities of SiF 4-based plasmas are discussed in the frame of the literature debate on SiH 4 vs SiF 4 as silicon precursor.

The mechanism of plasma-induced deposition of amorphous silicon from silane

Plasma Chemistry and Plasma Processing, 1990

Time-resolved mass spectrometric data show that the concentration of di-and trisilane, which are formed from monosilane under discharge conditions typical for the deposition of high electronic quality amorphous silicon, correlate with the measured deposition rate of a-Si. The data can be quantitatively and self-consistently described by a simple set o.f consecutive reactions:

Glow discharge deposition of amorphous silicon films: Role of SiF4/SiH4 gas ratio and of plasma modulation

Amorphous sllicon fi-lrns have been obtained under noduLatlon condltlons from siF4-H2 mlxtures and with slF4 addition to siH4-H2 mlxtures. The effect of these condltlons is to lncrease the film hornogenelty and to control the H content and lts bondtng conflguratlon. Under mo-ilulatlon conditions (Ml{) the H content j-s alwayJ higher than under continuous wave (cw) and the mlcrostructure parameter (R) exhlblts a more complex behavlour in dependence on duty cycle (D. c.) and period (p). The siFi addltion, ar high s1F4/s1Ha rarlo, causes changes ln the plasma. by increaslng the dlscharge-sl4nmetry and 1n the naterlal, by lncreaslng the dark conductlvlty and by inducing structural changes,

Amorphous, Polymorphous, and Microcrystalline Silicon Thin Films Deposited by Plasma at Low Temperatures

Crystalline and Non-crystalline Solids, 2016

The present chapter is devoted to the study of amorphous (a-Si:H), polymorphous (pm-Si:H), and microcrystalline (μc-Si:H) silicon, deposited by the plasma-enhanced chemical vapor deposition (PECVD) technique at low temperatures. We have studied the main deposition parameters that have strong influence on the optical, electrical, and structural properties of the polymorphous and microcrystalline materials. Our results reveal the key deposition conditions for obtained films with optical and electrical characteristics, which are suitable for applications on thin-film solar cells and semiconductor devices.

From amorphous to microcrystalline silicon deposition in SiF4–H2–He plasmas: in situ control by optical emission spectroscopy

Thin Solid Films, 2001

. Pure hydrogenated microcrystalline silicon c-SirH films were deposited by SiF ᎐H ᎐He plasmas at temperatures as low as 4 2 120ЊC and frequencies of 13.56 and 75 MHz. The plasma diagnostics by optical emission spectroscopy has allowed us to control the growth of c-SirH films. The silicon structure can be changed from pure amorphous to pure microcrystalline under the controlled variation of the densities of F atoms, H atoms and SiF radicals in the plasma phase. ᮊ 2001 Elsevier Science B.V. All n rights reserved.

Plasma deposition of thin film silicon: kinetics monitored by optical emission spectroscopy

Solar energy materials …, 2002

The optical emission spectroscopy technique is used to characterise the temporal behaviour of a pure silane plasma in the first 90 s after ignition of a static closed-chamber very high frequency glow discharge. Special interest is drawn to the formation of microcrystalline silicon (mc-Si:H) in absence of any hydrogen feedstock gas dilution. The kinetics of the emission lines of SiH n and H a is reported. The deposited films are characterised by photothermal deflection spectroscopy, Fourier transform infra red (FT-IR) absorption and show typical microcrystalline fingerprints; for the first time, such material is used as absorber layer in n-i-p type solar cell devices.