High Deposition Rate Pecvd Processes For Next Generation Tft-Lcds

1994 ◽  
Vol 345 ◽  
Author(s):  
J. F. M. Westendorp ◽  
H. Meiling ◽  
J. D. Pollock ◽  
D. W. Berrian ◽  
A. H. Laflamme ◽  
...  
Keyword(s):  
Glow Discharge ◽  
Deposition Rate ◽  
Rf Discharge ◽  
High Yield ◽  
High Deposition Rate ◽  
Very High Frequency ◽  
Doped Semiconductors ◽  
Deposition Rates ◽  
Powder Formation ◽  
High Production

AbstractThe demand for lower cost per panel in TFT-LCD production is driving the PECVD market to deposition systems that combine high throughput and uptime with high yield. Today it is generally believed that a multichamber system that combines a number of single-panel deposition chambers is the best way to achieve these goals.For these PECVD systems to be economical, the deposition rate of a-Si:H, SiNx and SiO2 has to be in the 1200–1500 Å/min range. In 13.56 MHz parallel-plate glow discharge systems SiNx and SiO2 deposition rates exceeding 1500 Å/min are commonly achieved, whereas the deposition rate of a-Si:H is limited to 100–200 Å/min due to powder formation. Over the last 5 years significant progress has been made to increase the deposition rate of a-Si:H. Methods include the use of very-high-frequency glow discharge (VHF-GD) and pulsing of the rf discharge. However, substrate sizes never exceeded 100mm×100mm.We have developed a multichamber PECVD system for TFT-LCD production where VHFGD is used to obtain uniform high deposition rates for (doped) semiconductors and insulators, such as a-Si:H, n+ a-Si:H, SiNx and SiO2 over areas as large as 470mm×370mm. Even at deposition rates well above 1200 Å/min hydrogen in a-Si:H is exclusively bound as monohydride. The optoelectronic properties of the films are at least as good as those of their 13.56 MHz counterparts and thus good-quality TFTs can be obtained. At the same time the number of added particles is low allowing for high production yields.

High Deposition Rate a-Si:H for the Flat Panel Display Industry

1996 ◽  
Vol 420 ◽  
Author(s):  
J. Hautala ◽  
Z. Saleh ◽  
J. F. M. Westendorp ◽  
H. Meiling ◽  
S. Sherman ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Defect Density ◽  
Dark Conductivity ◽  
Critical Conditions ◽  
Process Conditions ◽  
High Deposition Rate ◽  
Flat Panel Display ◽  
Deposition Rates ◽  
Powder Formation ◽  
And Control

AbstractHigh deposition rates and good quality electrical properties and thickness uniformities over large areas are required for all three films (SiNx, a-Si:H and n+a-Si:H) composing the thin film transistors (TFTs) for the AMLCD industry, while maintaining high tool up-time and low particle formation. Generally these conditions have been achieved for most single-panel multichamber PECVD systems; however, it has become increasingly apparent that a compromise is drawn between the TFT mobility and the deposition rate of the a-Si:H layer. Thus it becomes essential to clearly assess the industry requirements for both deposition rates as well as TFT performance for the different device structures used for AMLCDs, and to discover and control these underlying material properties.The TEL VHF (40/60 MHz) PECVD system produces high quality, low defect density a- Si:H at deposition rates exceeding 1500 Å/min when analyzed by FTIR, CPM, photo and dark conductivity. Even though the low deposition rate a-Si:H exhibits very similar bulk properties, higher mobility TFTs are produced with a-Si:H deposited at lower RF power. Having both a high ion flux and low ion energy in the SiH4 discharge are likely the most critical conditions for controlling the a-Si:H quality and thus the TFT mobility. Increasing the RF frequency enhances both of these effects, as well as provides a higher deposition rate for a given power density and a higher power threshold for particle/powder formation. For these reasons it is likely a 40/60 MHz plasma will produce better performing TFTs for a given deposition rate when compared with a conventional 13.56 MIHz system. Other process conditions such as diluting the SiH4 in H2 or Ar also seem to play an important role in the optoelectronic properties of the a-Si:H film and ultimately the TFT performance.

Preparation of a-Si:H and a-SiGe:H I-Layers for Nip Solar Cells at High Deposition Rates Using a Very High Frequency Technique

1998 ◽  
Vol 507 ◽  
Author(s):  
S.J. Jones ◽  
X. Deng ◽  
T. Liu ◽  
M. Izu
Keyword(s):  
Solar Cells ◽  
Deposition Rate ◽  
High Frequency ◽  
High Efficiency ◽  
High Deposition Rate ◽  
Very High Frequency ◽  
Deposition Rates ◽  
Single Junction ◽  
Layer Deposition ◽  
Very High

ABSTRACTThe 70 MHz Plasma Enhance Chemical Vapor Deposition (PECVD) technique has been tested as a high deposition rate (10 A/s) process for the fabrication of a-Si:H and a-SiGe:H alloy ilayers for high efficiency nip solar cells. As a prelude to multi-junction cell fabrication, the deposition conditions used to make single-junction a-Si:H and a-SiGe:H cells using this Very High Frequency (VHF) method have been varied to optimize the material quality and the cell efficiencies. It was found that the efficiencies and the light stability for a-Si:H single-junction cells can be made to remain relatively constant as the i-layer deposition rate is varied from 1 to 10 Å/s. Also these stable efficiencies are similar to those for cells made at low deposition rates (1 Å/s) using the standard 13.56 MHz PECVD technique. For the a-SiGe:H cells of the same i-layer thickness, use of the VHF technique leads to cells with higher currents and an ability to more easily current match triple-junction cells prepared at high deposition rates which should lead to higher multi-junction efficiencies. Thus, use of this VHF method in the production of large area a- Si:H based multi-junction solar modules will allow for higher i-layer deposition rates, higher manufacturing throughput and reduced module cost.

High Deposition Rate a-Si:H for the Flat Panel Display Industry

1996 ◽  
Vol 424 ◽  
Author(s):  
J. Hautala ◽  
Z. Saleh ◽  
J. F. M. Westendorp ◽  
H. Meiling ◽  
S. Sherman ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Defect Density ◽  
Dark Conductivity ◽  
Critical Conditions ◽  
Process Conditions ◽  
High Deposition Rate ◽  
Flat Panel Display ◽  
Deposition Rates ◽  
Powder Formation ◽  
And Control

AbstractHigh deposition rates and good quality electrical properties and thickness uniformities over large areas are required for all three films (SiNx, a-Si:H and n+ a-Si:H) composing the thin film transistors (TFTs) for the AMLCD industry, while maintaining high tool up-time and low particle formation. Generally these conditions have been achieved for most single-panel multichamber PECVD systems; however, it has become increasingly apparent that a compromise is drawn between the TFT mobility and the deposition rate of the a-Si:H layer. Thus it becomes essential to clearly assess the industry requirements for both deposition rates as well as TFT performance for the different device structures used for AMLCDs, and to discover and control these underlying material properties.The TEL VHF (40/60 MHz) PECVD system produces high quality, low defect density a- Si:H at deposition rates exceeding 1500 Å/min when analyzed by FTIR, CPM, photo and dark conductivity. Even though the low deposition rate a-Si:H exhibits very similar bulk properties, higher mobility TFTs are produced with a-Si:H deposited at lower RF power. Having both a high ion flux and low ion energy in the SiH4 discharge are likely the most critical conditions for controlling the a-Si:H quality and thus the TFT mobility. Increasing the RF frequency enhances both of these effects, as well as provides a higher deposition rate for a given power density and a higher power threshold for particle/powder formation. For these reasons it is likely a 40/60 MHz plasma will produce better performing TFTs for a given deposition rate when compared with a conventional 13.56 MHz system. Other process conditions such as diluting the SiH4 in H2 or Ar also seem to play an important role in the optoelectronic properties of the a-Si:H film and ultimately the TFT performance.

Impact of Deposition Rate on the Structural and Magnetic Properties of Sputtered Ni/Cu Multilayer Thin Films

2017 ◽  
Vol 73 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Ali Karpuz ◽  
Salih Colmekci ◽  
Hakan Kockar ◽  
Hilal Kuru ◽  
Mehmet Uckun
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Deposition Rate ◽  
High Rate ◽  
Cubic Phase ◽  
High Deposition Rate ◽  
Multilayer Thin Films ◽  
Face Centered Cubic ◽  
Deposition Rates ◽  
Cu Films

AbstractThe structural and corresponding magnetic properties of Ni/Cu films sputtered at low and high deposition rates were investigated as there is a limited number of related studies in this field. 5[Ni(10 nm)/Cu(30 nm)] multilayer thin films were deposited using two DC sputtering sources at low (0.02 nm/s) and high (0.10 nm/s) deposition rates of Ni layers. A face centered cubic phase was detected for both films. The surface of the film sputtered at the low deposition rate has a lot of micro-grains distributed uniformly and with sizes from 0.1 to 0.4 μm. Also, it has a vertical acicular morphology. At high deposition rate, the number of micro-grains considerably decreased, and some of their sizes increased up to 1 μm. The surface of the Ni/Cu multilayer deposited at the low rate has a relatively more grainy and rugged structure, whereas the surface of the film deposited at the high rate has a relatively larger lateral size of surface grains with a relatively fine morphology. Saturation magnetisation, Ms, values were 90 and 138 emu/cm3 for deposition rates of 0.02 and 0.10 nm/s, respectively. Remanence, Mr, values were also found to be 48 and 71 emu/cm3 for the low and high deposition rates, respectively. The coercivity, Hc, values were 46 and 65 Oe for the low and high Ni deposition rates, respectively. The changes in the film surfaces provoked the changes in the Hc values. The Ms, Mr, and Hc values of the 5[Ni(10 nm)/Cu(30 nm)] films can be adjusted considering the surface morphologies and film contents caused by the different Ni deposition rates.

Large Grain Size and High Deposition Rate for Microcrystalline Silicon Prepared by VHF-GD

1994 ◽  
Vol 358 ◽  
Author(s):  
P. Hapke ◽  
F. Finger ◽  
M. Luysberg ◽  
R. Carius ◽  
H. Wagner
Keyword(s):  
Grain Size ◽  
Deposition Rate ◽  
High Frequency ◽  
Excitation Frequency ◽  
Chemical Vapour ◽  
High Deposition Rate ◽  
Very High Frequency ◽  
Deposition Parameters ◽  
Plasma Excitation ◽  
Very High

ABSTRACTThe growth mechanism and material properties of -type µc-Si:H prepared with plasma enhanced chemical vapour deposition in the very high frequency range is investigated. By increasing the plasma excitation frequency the grain size, deposition rate and Hall mobility can be simultaneously increased without having to adjust other deposition parameters in particular the temperature. This effect is explained by an enhanced selective etching of amorphous tissue and grain boundary regions together with a sufficient supply of growth species at high frequency plasmas.

Electronic transport study of high deposition rate HWCVD a-Si:H by the microwavephotomixing technique

2001 ◽  
Vol 664 ◽  
Author(s):  
S.R. Sheng ◽  
R. Braunstein ◽  
B.P. Nelson ◽  
Y. Xu
Keyword(s):  
Substrate Temperature ◽  
Deposition Rate ◽  
Flow Rate ◽  
Electronic Transport ◽  
High Deposition Rate ◽  
Deposition Pressure ◽  
Film Properties ◽  
High Quality ◽  
Deposition Rates ◽  
Potential Fluctuations

ABSTRACTThe electronic transport properties of high deposition rate a-Si:H films prepared by HWCVD have been investigated in detail by employing the microwave photomixing technique. The high deposition rates (up to 1 µm/min.) were achieved by adding a second filament, increasing deposition pressure, silane flow rate, and decreasing filament-to-substrate distance. The effect of the deposition rate on the resultant film properties with respect to the substrate temperature, deposition pressure and silane flow rate was studied. It was found that the film transport properties do not change monotonically with increasing deposition rate. The photoconductivity peaks at ∼70-90 Å/s, where both the drift mobility and lifetime peak, consistent with the deposition rate dependence of the range and depth of the potential fluctuations. High quality, such as a photoconductivity-to-dark-conductivity ratio of ∼105 and nearly constant low charged defect density, can be maintained at deposition rates up to ∼150 Å/s, beyond which the film properties deteriorate rapidly as a result of an enhanced effect of the long-range potential fluctuations due to a considerable increase in the concentration of the charged defects. Our present results indicate that medium silane flow rate, low pressure, and higher substrate temperature are generally required to maintain high quality films at high deposition rates.

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