Comparative and integrative study of Langmuir probe and optical emission spectroscopy in a variable magnetic field electron cyclotron resonance chemical vapor deposition process used for depositing hydrogenated amorphous silicon thin films

Hu, Lei; Ruan, G.M.; Wei, Ta‐Chin; Wang, C.J.; Lin, Yu; Lee, Chien Chieh; Kawai, Yoshinobu; Li, Tomi T.

doi:10.1016/j.tsf.2014.05.063

Cited by 4 publications

(2 citation statements)

References 28 publications

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“…H β /H α is a more reliable index than Si/SiH for determining the trend of electron temperature; this result is consistent with that obtained in our previous study. 41 (3) Although the auxiliary magnetic coils in the process chamber provide opposite-direction magnetic fields and reduce the effect of the magnetic fields, the shadowing effect is the major cause of deviation on N i in our ECR-CVD system. The effect of magnetic fields on the LP measurement is more severe than the anticipated effect.…”

Section: Discussionmentioning

confidence: 99%

Investigation of Electron Cyclotron Resonance Chemical Vapor Deposition Process for a-Si:H Deposition, Film Characterization and In Situ Plasma Diagnostics

Wang

Lin

et al. 2015

ECS J. Solid State Sci. Technol.

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We present the application of quadrupole mass spectrometry (QMS) with threshold ionization mass spectrometry (TIMS), optical emission spectroscopy (OES) with an actinometry method, and Langmuir probe (LP) as an integrated technique for in situ plasma characterization of the electron cyclotron resonance chemical vapor deposition (ECR-CVD) of hydrogenated amorphous silicon (a-Si:H). The main aim of this study was to determine the relationship among the process parameters, plasma characteristics, and thin film properties, including the microstructure parameter (R * ), hydrogen content (C H ), and a-Si:H film growth rate. The physical properties of plasma, such as the electron density (N e ), electron energy (T e ), and sheath potential (V s ), were studied using an LP and OES. In addition to the general plasma properties, the ion density (N i ) and plasma electronegativity were examined. The results indicate the ECR plasma source has high potential for producing a high-quality a-Si:H film because of the availability of few high silanes (Si n H 2n+2, n > 2); furthermore, the results indicate an obvious difference in the QMS analysis results between plasma and gas. Therefore, the consumption of parent molecules must be considered. The TIMS method was applied to estimate the relative concentration of ground-state silane radicals (SiH x , x < 4) and consumption of SiH 4 . The results indicate that, in addition to the degree of ionization, the consumption of SiH 4 and V s are key factors affecting the thin film growth rate. When microwave power density increases, the values of N i , N e , and V s increase considerably, but the plasma electronegativity remains unchanged. Furthermore, we compared our results with the TIMS analysis reported by other authors and found that the ratio of SiH 2 to SiH 3 obtained using QMS and TIMS can be considered an indicator of film quality for R * in the ECR-CVD process. Over the past 30 years, numerous vapor deposition techniques have been developed and applied in hydrogenated amorphous silicon (a-Si:H) thin film deposition processes, such as RF-PECVD, 1 VHF-PECVD, 2,3 hotwire-CVD, 4 photo-CVD, 5 and electron cyclotron resonance chemical vapor deposition (ECR-CVD).6,7 Among these CVD processes, the ECR-CVD process was a vital technology in thin film manufacturing processes. The main advantages of this process are outlined as follows: (1) This process does not result in electrode contamination, (2) it is characterized by low ion bombardment effects, (3) it can be used to generate high-density plasma at low working pressure (i.e., less than 10 −2 Pa), (4) it can be used to control ion energy extensively and independently from the ion flux, and (5) it is characterized by high deposition rates of thin films. [8][9][10][11] Thus, this technique has great potential for preparing a high-quality a-Si:H film because it demonstrates fewer surface defects and less photocarrier loss in thin films or a heterojunction with intrinsic (HIT) structure solar cell.12 Compared with other high-density plasma ...

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Section: Discussionmentioning

confidence: 99%

Investigation of Electron Cyclotron Resonance Chemical Vapor Deposition Process for a-Si:H Deposition, Film Characterization and In Situ Plasma Diagnostics

Wang

Lin

et al. 2015

ECS J. Solid State Sci. Technol.

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“…The detail of ECR system is shown by:. 25 In our ECRCVD, the most stable plasma condition is observed by the main coil current of 55A. The other deposition parameters were as follows: the source gas supplied via an inlet valve upon the ECR region included Ar, H 2 and 10% GeH4 diluted with He; the flow rate ratio of H 2 /GeH 4 is 16; the microwave power is 800 W. The deposition rate and crystallization rate of the Ge films is observed (SE).…”

Section: Methodsmentioning

confidence: 99%

Strain-Controlled of Compressive/Tensile Ge Epilayers on Si by Electron Cyclotron Resonance Chemical Vapor Deposition

Kuo

Lin

Lee

et al. 2016

ECS J. Solid State Sci. Technol.

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In this study, we use electron cyclotron resonance chemical vapor deposition to investigate the strain behavior in Ge epilayers grown on silicon at a low temperature of 220°C. The strain in the Ge epilayers is transformed from compressive (−0.567%) to tensile (0.15%) as the process pressure decreases and main coil current increases. This tensile strain is due to intrinsic stress in the Ge epilayers at high process pressure and low main coil current. Besides, the Ge atoms have higher kinetic energy and shorter mean free path at low process pressure and high main coil current, which causes atomic bombardment effect on the Ge surfaces frequently. Thus, the intrinsic stress in Ge epilayers become compressive. The absorption coefficient of tensile and compressive strain in Ge films are measured using a UV–VIS-NIR spectrophotometer. The results show the absorption coefficients of the tensile strain Ge epilayer has a redshift condition on the absorption edge compare with compressive strain Ge epilayers. Finally, the structure information of the Ge epilayers is identified by atomic force microscopy and transmission electron microscopy. This strain control technology is modulated by film growth parameter, which can adjust the Ge bandgap for the device requirement.

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Magnetic Field Resonance and Pressure Effects on Epitaxial Thin Film Deposition and In Situ Plasma Diagnostics

Yang

Yeh

et al. 2017

Plasma Chem Plasma Process

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Comparative and integrative study of Langmuir probe and optical emission spectroscopy in a variable magnetic field electron cyclotron resonance chemical vapor deposition process used for depositing hydrogenated amorphous silicon thin films

Cited by 4 publications

References 28 publications

Investigation of Electron Cyclotron Resonance Chemical Vapor Deposition Process for a-Si:H Deposition, Film Characterization and In Situ Plasma Diagnostics

Investigation of Electron Cyclotron Resonance Chemical Vapor Deposition Process for a-Si:H Deposition, Film Characterization and In Situ Plasma Diagnostics

Strain-Controlled of Compressive/Tensile Ge Epilayers on Si by Electron Cyclotron Resonance Chemical Vapor Deposition

Magnetic Field Resonance and Pressure Effects on Epitaxial Thin Film Deposition and In Situ Plasma Diagnostics

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