Connection between hydrogen plasma treatment and etching of amorphous phase in the layer-by-layer technique with very high frequency plasma excitation

Vetterl, O.; Hapke, P.; Houben, Lothar; Finger, F.; Carius, R.; Wagner, H.

doi:10.1063/1.369616

Cited by 10 publications

(6 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Briefly, the method is based on a short H 2 plasma treatment step during which the gas phase density of SiH 4 ͑i.e., the main etch product released from the film surface͒ is detected. Atomic hydrogen preferentially inserts into strained Si-Si bonds 11,12 resulting in a higher etch rate of a-Si: H relative to c-Si: H. 13,14 The SiH 4 density in the plasma is observed directly by infrared absorption spectroscopy 15 or, alternatively, indirectly by OES. In the latter method, the SiH * emission is detected as originating from SiH 4 etch product dissociation by electron impact, as also reported by Westlake and Heintze.…”

mentioning

confidence: 99%

“…Subsequently, after a pump down to Ͻ0.1 Torr, a H 2 plasma treatment of the silicon film was carried out using the same H 2 flow, pressure, plasma power, and substrate temperature as applied under deposition ͑note that these conditions were kept constant within a deposition series͒. The H 2 plasma treatment time was set at Ͻ60 s to diminish H-induced material modification 11,14,18 and the influence of redeposition. 19,20 The time averaged baseline corrected SiH * emission at 414.3 nm proved to scale with the SiH 4 density 13,21 and is used here as a measure for the abundance of etch products during H 2 plasma treatment.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Probing the phase composition of silicon films in situ by etch product detection

Dingemans

Donker

Gordijn

et al. 2007

Applied Physics Letters

View full text Add to dashboard Cite

Exploiting the higher etch probability for amorphous silicon relative to crystalline silicon, the transiently evolving phase composition of silicon films in the microcrystalline growth regime was probed in situ by monitoring the etch product (SiH4) gas density during a short H2 plasma treatment step. Etch product detection took place by the easy-to-implement techniques of optical emission spectroscopy and infrared absorption spectroscopy. The phase composition of the films was probed as a function of the SiH4 concentration during deposition and as a function of the film thickness. The in situ results were corroborated by Raman spectroscopy and solar cell analysis.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Probing the phase composition of silicon films in situ by etch product detection

Dingemans

Donker

Gordijn

et al. 2007

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…In general, the effect of hydrogen dilution on the growth of nc-Si is interpreted in terms of several growth models, including the hydrogen etching model, the surface mobility model, and the chemical annealing model. [6,9,20,21] In our case, the decreased deposition rate and the improved crystalline fraction with increasing hydrogen dilution ratio indicates that hydrogen etching is important in the formation of nc-Si. It is also found that the crystalline fraction of the ultrathin films is apparently lower than that of the thick film under the same hydrogen dilution ratio.…”

Section: Resultsmentioning

confidence: 52%

Growth characteristics of amorphous-layer-free nanocrystalline silicon films fabricated by very high frequency PECVD at 250°C

Guo¹,

Rui²,

Song³

et al. 2012

Chinese Phys. B

View full text Add to dashboard Cite

Amorphous-layer-free nanocrystalline silicon films were prepared by a very high frequency plasma enhanced chemical vapor deposition (PECVD) technique using hydrogen-diluted SiH 4 at 250 • C. The dependence of the crystallinity of the film on the hydrogen dilution ratio and the film thickness was investigated. Raman spectra show that the thickness of the initial amorphous incubation layer on silicon oxide gradually decreases with increasing hydrogen dilution ratio. High-resolution transmission electron microscopy reveals that the initial amorphous incubation layer can be completely eliminated at a hydrogen dilution ratio of 98%, which is lower than that needed for the growth of amorphous-layer-free nanocrystalline silicon using an excitation frequency of 13.56 MHz. More studies on the microstructure evolution of the initial amorphous incubation layer with hydrogen dilution ratios were performed using Fourier-transform infrared spectroscopy. It is suggested that the high hydrogen dilution, as well as the higher plasma excitation frequency, plays an important role in the formation of amorphous-layer-free nanocrystalline silicon films.

show abstract

“…Finally, it is interesting to note that the PF‐PECVD process also bears similarity with reports on the layer‐by‐layer deposition of microcrystalline silicon. In the latter case, the deposition of an ultrathin amorphous silicon film (H 2 /SiH 4 plasma) was alternated by H 2 plasma treatment to crystallize the material 55…”

Section: Resultsmentioning

confidence: 99%

Plasma‐enhanced Chemical Vapor Deposition of Aluminum Oxide Using Ultrashort Precursor Injection Pulses

Dingemans

Sanden

Kessels

2012

Plasma Processes & Polymers

View full text Add to dashboard Cite

An alternative plasma‐enhanced chemical vapor deposition (PECVD) method is developed and applied for the deposition of high‐quality aluminum oxide (AlOx) films. The PECVD method combines a continuous plasma with ultrashort precursor injection pulses. We demonstrate that the modulation of the precursor flow in the reactor leads to enhanced control over plasma‐surface interactions. By variation of the time interval between the sequential Al(CH3)3 precursor injection pulses (10–50 ms) into the O2 plasma, the deposition rate (>30 nm · min−1) and material properties can be tailored. In situ diagnostics revealed that the deposition process is governed by fast precursor depletion and film growth directly after the precursor pulse. Subsequently, in the remainder of the interval between the precursor pulses, densification of the layer takes place under influence of the O2 plasma. The resulting AlOx films exhibit a low impurity content and refractive index >1.6 for optimized process settings. The films can be applied for effective surface passivation of Si as indicated by ultralow surface recombination velocities <1 cm · s−1. The structural properties and interface quality are quite similar as obtained for atomic layer deposited films. We anticipate that pulsed‐flow PECVD processes may also prove beneficial for the synthesis of other functional thin films.

show abstract

Connection between hydrogen plasma treatment and etching of amorphous phase in the layer-by-layer technique with very high frequency plasma excitation

Cited by 10 publications

References 11 publications

Probing the phase composition of silicon films in situ by etch product detection

Probing the phase composition of silicon films in situ by etch product detection

Growth characteristics of amorphous-layer-free nanocrystalline silicon films fabricated by very high frequency PECVD at 250°C

Plasma‐enhanced Chemical Vapor Deposition of Aluminum Oxide Using Ultrashort Precursor Injection Pulses

Contact Info

Product

Resources

About