Correlation of Performance and Hot Carrier Stress Reliability of Polycrystalline Silicon Thin-Film Transistors With Substrates and Substrate Coating

1998 ◽  
Vol 508 ◽  
Author(s):  
Y. Z. Wang ◽  
O. O. Awadelkarim
Keyword(s):  
Coating Thickness ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Silicon Thin Film ◽  
Hot Carrier ◽  
Coated Glass ◽  
Glass Substrates ◽  
Hot Carrier Stress ◽  
Pressure Chemical ◽  
The Impact

AbstractWe report on the performance and hot carrier stress (HCS) reliability of n-channel poly-Si TFTs fabricated on bare or SiO2-coated low-alkali glass, or fused silica substrates. Low-pressure chemical vapor deposited (LPCVD) SiO2 films with different thicknesses are used as impurity diffusion barrier layers. We have found that the performance and HCS reliability of n-TFTs on the SiO2-coated glass are superior to those of n-TFTs on bare glass, and comparable to those of TFTs on fused silica. We also explore the impact of the SiO2 coating thickness on the performance and HCS reliability of the TFTs. The HCS reliability of the TFTs on SiO2-coated glass substrates is observed to depend on the SiO2 coating thickness. This is explained in terms of a phenomenological model which involves impurity and grain boundary traps.

Investigation of the off-current in amorphous silicon thin film transistors for SiO2 and SiNx. gate insulators

1996 ◽  
Vol 424 ◽  
Author(s):  
Jeong Hyun Kim ◽  
Woong Sik Choi ◽  
Chan Hee Hong ◽  
Hoe Sup Soh
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Chemical Vapor ◽  
Interface State ◽  
State Density ◽  
Gate Insulator ◽  
Defect States ◽  
Silicon Thin Film ◽  
Pressure Chemical

AbstractThe off current behavior of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs) with an atmospheric pressure chemical vapor deposition (APCVD) silicon dioxide (SiO2) gate insulator were investigated at negative gate voltages. The a-Si:H TFT with SiO2 gate insulator has small off currents and large activation energy (Ea) of the off current compared to the a-Si:H TFT with SiNx gate insulator. The holes induced in the channel by negative gate voltage seem to be trapped in the defect states near the a-Si:H/SiO2 interface. The interface state density in the lower half of the band gap of a-Si:H/SiO2 appears to be much higher than that for a-Si:H/SiNx.

Impact of In Situ NH3 pre-treatment of LPCVD SiN passivation on GaN HEMT performance

2022 ◽  
Author(s):  
Ding-Yuan Chen ◽  
Axel R Persson ◽  
Kai Hsin Wen ◽  
Daniel Sommer ◽  
Jan Gruenenpuett ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Untreated Sample ◽  
Pressure Chemical ◽  
Gan Hemts ◽  
Pre Treatment ◽  
The Impact

Abstract The impact on the performance of GaN HEMTs of in situ ammonia (NH3) pre-treatment prior to the deposition of silicon nitride (SiN) passivation with low-pressure chemical vapor deposition is investigated. Three different NH3 pre-treatment durations (0, 3, and 10 minutes) were compared in terms of interface properties and device performance. A reduction of oxygen at the interface between SiN and epi-structure is detected by Scanning Transmission Electron Microscopy-Electron Energy Loss Spectroscopy measurements in the sample subjected to 10 minutes of pre-treatment. The samples subjected to NH3 pre-treatment show a reduced surface-related current dispersion of 9 % (compared to 16% for the untreated sample), which is attributed to the reduction of oxygen at the SiN/epi interface. Furthermore, NH3 pre-treatment for 10 minutes significantly improves the current dispersion uniformity from 14.5 % to 1.9 %. The reduced trapping effects result in a high output power of 3.4 W/mm at 3 GHz (compared to 2.6 W/mm for the untreated sample). These results demonstrate that the in situ NH3 pre-treatment before low-pressure chemical vapor deposition of SiN passivation is critical and can effectively improves the large-signal microwave performance of GaN HEMTs.

Variable Angle Spectroscopic Ellipsometric Characterization of Polycrystalline Silicon thin Film Multilayer Structures

1991 ◽  
Vol 238 ◽  
Author(s):  
Paul G. Snyder ◽  
Yi-Ming Xiong ◽  
John A. Woollam ◽  
Eric R. Krosche
Keyword(s):  
Polycrystalline Silicon ◽  
Composite Layer ◽  
Chemical Vapor ◽  
Silicon Thin Film ◽  
Cross Sectional ◽  
Additional Information ◽  
Variable Angle ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Annealing Effects

ABSTRACTVariable angle spectroscopie ellipsometry (VASE), a nondestructive optical technique, was used to characterize two different multilayer samples, each having a low-pressure chemical vapor deposited polycrystalline silicon (poly-Si) layer. Analysis of these samples by cross-sectional transmission electron microscopy (XTEM) revealed large changes in grain size, between the undoped, as-deposited, and doped, annealed poly-Si layers. Roughness at the top of the poly-Si layers was also observed by XTEM. These features, together with the other structure parameters (thickness and composition), were analyzed ellipsometrically by fitting the measured VASE spectra with appropriate multilayer models. Each composite layer (surface overlayer, interfacial layer, and poly-Si layer) was modeled as a physical mixture, using the Bruggeman effective medium approximation. The ellipsometrically determined thicknesses were in very good agreement with the corresponding results measured by XTEM. Furthermore, VASE analysis provided additional information about the relative fractions of the constituent materials in the different composite layers. Thus, it quantitatively characterized the surface and interracial properties, and also the doping and annealing effects on the microstructure of poly-Si layers.

Growth of Antimony Thin Films Using Perbenzylated Organometallic Precursors

1998 ◽  
Vol 547 ◽  
Author(s):  
Michael P. Remington ◽  
Smuruthi Kamepalli ◽  
Philip Boudjouk ◽  
Bryan R. Jarabek ◽  
Dean G. Grier ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Carbon ◽  
Design Strategies ◽  
Glass Substrates ◽  
Pressure Chemical ◽  
Organometallic Precursors

AbstractThe low temperature (ca. 300°C) deposition of antimony films by low-pressure chemical vapor deposition (LPCVD) on glass substrates from tribenzylantimony, Bn3Sb, is described. The facile elimination of the benzyl ligands results in preferentially oriented antimony films with low carbon content. The pyrolysis, decomposition mechanism and precursor design strategies are discussed. In addition, the deposition of bismuth from tribenzylbismuth, Bn3Bi, is presented. The potential for alloy growth using these precursors is discussed. Resulting films were characterized by XRD, SEM, and AFM.

Deposition of Tungsten Nitride thin Films from (tBuN)2w(NHtBu)2

1991 ◽  
Vol 250 ◽  
Author(s):  
Hsin-Tien Chiu ◽  
Shiow-Huey Chuang
Keyword(s):  
Thin Films ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
Gas Chromatography Mass Spectrometry ◽  
Elemental Distribution ◽  
Tungsten Nitride ◽  
Wavelength Dispersive Spectroscopy ◽  
Glass Substrates ◽  
Pressure Chemical

AbstractThe possibility of growing tungsten nitride thin films from (tBuN)2W(NHtBu)2, a single-source molecular precursor with two nitrogen to tungsten double bonds, by low pressure chemical vapor deposition (LPCVD) was investigated. Deposition of thin films on silicon and glass substrates was carried out at temperatures 500 – 650 °C in a cold-wall reactor while the precursor was vaporized at 60 – 100 °C. Elemental composition of the thin films, studied by wavelength dispersive spectroscopy (WDS), is best described as WNx (x = 0.8 – 1.8). Elemental distribution within the films, studied by Auger depth profiling, is uniform. X-ray diffraction (XRD) studies show that the films have a cubic structure with a lattice parameter a = 4.14 – 4.18 Å. A stoichiometric WN thin film has a lattice parameter a equal to 4.154 Å. Volatile products, trapped at −196°C, were analyzed by nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). Isobutylene, acetonitrile, hydrogen cyanide and ammonia were detected in the condensable mixtures.

Poly-Resistor Thin Film Formation by Excimer Laser Micromachine

2015 ◽  
Vol 780 ◽  
pp. 17-21
Author(s):  
A.F.M. Anuar ◽  
Yufridin Wahab ◽  
M.Z. Zainol ◽  
H. Fazmir ◽  
M. Najmi ◽  
...  
Keyword(s):  
Thin Film ◽  
Excimer Laser ◽  
Laser Energy ◽  
Film Formation ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Beam Size ◽  
Silicon Thin Film ◽  
Pressure Chemical ◽  
Krf Excimer Laser

A simple theoretical model and resistor fabrication for calculating the resistance of a polycrystalline silicon thin film is presented. The resistance value for poly-resistor is perfomed in terms of polysilicon thickness and its total area. The KrF excimer laser micromachine is used in assisting the resistor formation for a low pressure chemical vapor deposition (LPCVD) based polysilicon. Laser micromachine with three main parameters is used to aid the fabrication of the poly-resistor; namely as the pulse rate (i.e. number of laser pulses per second), laser beam size and laser energy. These parameters have been investigated to create the isolation between materials and also to achieve the desired poly-resistor shape. Preliminary results show that the 35 um beam size and 15 mJ of energy level is the most effective parameter to produce the pattern. Poly-resistor formation with 12 and 21 number of squares shows the total average resistance of 303.52 Ω and 210.14 Ω respectively. The laser micromachine process also significantly reduce the total time and number of process steps that are required for resistor fabrication.

Chemical Vapor Deposition of Silicon Carbide Using a Novel Organometallic Precursor

1988 ◽  
Vol 131 ◽  
Author(s):  
Wei Lee ◽  
Leonard V. Interrante ◽  
Corrina Czekaj ◽  
John Hudson ◽  
Klaus Lenz ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Crystal Silicon ◽  
Organometallic Precursor ◽  
Pressure Chemical ◽  
By Products

ABSTRACTDense silicon carbide films have been prepared by low pressure chemical vapor deposition (LPCVD) using a volatile, heterocyclic, carbosilane precursor, MeHSiCH2SiCH2Me(CH2SiMeH2). At deposition temperatures between 700 and 800° C, polycrystalline, stoichiometric SiC films have been deposited on single crystal silicon and fused silica substrates. Optical microscopy and SEM analyses indicated formation of a transparent yellow film with a uniform, featureless surface and good adherence to the Si(lll) substrate. The results of preliminary studies of the nature of the gaseous by-products of the CVD processes and ultrahigh vacuum physisorption and decomposition of the precursor on Si(100) substrates are discussed.

scholarly journals Enhanced degradation in polycrystalline silicon thin-film transistors under dynamic hot-carrier stress

2001 ◽  
Vol 22 (10) ◽  
pp. 475-477 ◽  
Author(s):  
Kow Ming Chang ◽  
Yuan Hung Chung ◽  
Gin Ming Lin ◽  
Chi Gun Deng ◽  
Jian Hong Lin
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Polycrystalline Silicon ◽  
Silicon Thin Film ◽  
Hot Carrier ◽  
Hot Carrier Stress ◽  
Enhanced Degradation
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