Homoepitaxial Chemical Vapor Deposition of up to 150 μm Thick 4H-SiC Epilayers in a 10×100 mm Batch Reactor

2016 ◽  
Vol 858 ◽  
pp. 129-132 ◽  
Author(s):  
Bernd Thomas ◽  
Jie Zhang ◽  
Gil Yong Chung ◽  
Willie Bowen ◽  
Victor Torres ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Statistical Data ◽  
Laser Light ◽  
Defect Density ◽  
Batch Reactor ◽  
Chemical Vapor ◽  
Layer Growth ◽  
Average Lifetime ◽  
Thick Layers

In this paper we present results on the growth of low-doped thick epitaxial layers on 4° off-oriented 4H-SiC using a warm-wall multi-wafer CVD system (Aixtron VP2800WW). Statistical data on doping and thickness of 25 μm to 40 μm layer growth show results similar to standard epilayer growth (5-15 μm). Improvements in thickness and doping uniformity as well as the reduction of epitaxial defects has boosted the quality of 25 μm to 40 μm thick epilayers. Laser light scattering measurements resulted in projected device yields with median values of 83% and 96% for 5×5 mm2 and 2×2 mm2 die size, respectively. This corresponds to a low epitaxial defect density of < 0.75 cm-2 in 25-40 μm thick epilayers. This paper also presents results of 60 μm to 150 μm thick epitaxial layer growth. Excellent results for doping, thickness and carrier lifetime were achieved. As an example results of a fully loaded 10×100mm run with 150 μm thick epilayers are presented. Wafer-to-wafer doping and thickness values of 3.7 % and 3.4% for sigma/mean were accomplished, respectively. Typical average lifetime values of 5 μs to 6 μs were measured on the 150 μm thick layers without post-epi treatments.

scholarly journals Study on Annealing Process of Aluminum Oxide Passivation Layer for PERC Solar Cells

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1052
Author(s):  
Yu-Chun Huang ◽  
Ricky Wenkuei Chuang
Keyword(s):  
Carrier Lifetime ◽  
Defect Density ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Minority Carrier Lifetime ◽  
Atomic Layer ◽  
Film Structure ◽  
Open Circuit ◽  
Annealing Process ◽  
Surface Recombination Velocity

In this study, Atomic Layer Deposition (ALD) equipment was used to deposit Al2O3 film on a p-type silicon wafer, trimethylaluminum (TMA) and H2O were used as precursor materials, and then the post-annealing process was conducted under atmospheric pressure. The Al2O3 films annealed at different temperatures between 200–500 °C were compared to ascertain the effect of passivation films and to confirm the changes in film structure and thickness before and after annealing through TEM images. Furthermore, the negative fixed charge and interface defect density were analyzed using the C-V measurement method. Photo-induced carrier generation was used to measure the effective minority carrier lifetime, the implied open-circuit voltage, and the effective surface recombination velocity of the film. The carrier lifetime was found to be the longest (2181.7 μs) for Al2O3/Si post-annealed at 400 °C. Finally, with the use of VHF (40.68 MHz) plasma-enhanced chemical vapor deposition (PECVD) equipment, a silicon nitride (SiNx) film was plated as an anti-reflection layer over the front side of the wafer and as a capping layer on the back to realize a passivated emitter and rear contact (PERC) solar cell with optimal efficiency up to 21.54%.

Ge Growth on Nanostructured Silicon Surfaces

2005 ◽  
Vol 862 ◽  
Author(s):  
Ganesh Vanamu ◽  
Abhaya K. Datye ◽  
Saleem H. Zaidi
Keyword(s):  
Electron Microscopy ◽  
Dislocation Density ◽  
Full Width Half Maximum ◽  
Defect Density ◽  
Chemical Vapor ◽  
Silicon Surfaces ◽  
X Ray Diffraction ◽  
Etch Pit ◽  
Transmission Electron

AbstractWe report highest quality Ge epilayers on nanoscale patterned Si structures. 100% Ge films of 10 μm are deposited using chemical vapor deposition. The quality of Ge layers was examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution x-ray diffraction (HRXRD) measurements. The defect density was evaluated using etch pit density measurements. We have obtained lowest dislocation density (5×105 cm-2) Ge films on the nanopatterned Si structures. The full width half maximum peaks of the reciprocal space maps of Ge epilayers on the nanopatterned Si showed 93 arc sec. We were able to get rid of the crosshatch pattern on the Ge surface grown on the nanopatterned Si. We also showed that there is a significant improvement of the quality of the Ge epilayers in the nanopatterned Si compared to an unpatterned Si. We observed nearly three-order magnitude decrease in the dislocation density in the patterned compared to the unpatterned structures. The Ge epilayer in the patterned Si has a dislocation density of 5×105 cm-2 as compared to 6×108 cm-2 for unpatterned Si.

Progress in Large-Area 4H-SiC Epitaxial Layer Growth in a Warm-Wall Planetary Reactor

2014 ◽  
Vol 778-780 ◽  
pp. 103-108 ◽  
Author(s):  
Bernd Thomas ◽  
Darren M. Hansen ◽  
Jie Zhang ◽  
Mark J. Loboda ◽  
Junichi Uchiyama ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Defect Density ◽  
Layer Growth ◽  
Power Devices ◽  
Large Area ◽  
Defect Reduction ◽  
Mean Values ◽  
Bipolar Devices ◽  
Thickness Measurements

Results are presented for epitaxial SiC layers grown on 100 mm and 150 mm wafers suitable for power devices by CVD using a VP2800WW multi-wafer reactor with 10×100mm and 6×150mm configurations. We have demonstrated continuous improvement in uniformity for thickness and doping, as well as in defect reduction in standard epitaxy on 100 mm wafers. Thickness and doping sigma/mean values of <1.5% and <8%, respectively, could be routinely achieved. Doping and thickness measurements of 30 μm layer growth show results similar to standard epilayer growth. The averaged projected site yields of 80% for 5x5 mm2 and of 96% for 2x2 mm2 correspond to a low epitaxial defect density of <1 cm="" sup="">-2 in 30μm thick epilayers. Epilayer structures for bipolar devices like PiN diodes and BJTs are shown. The interface regions between nitrogen doped and aluminum doped layers show an abrupt transition of dopant concentration. Wafer quality of 100 mm and 150 mm material is presented as an important base factor for excellent epitaxial layer quality. It is shown that 150 mm substrates exhibit TSD and BPD densities very similar to the 100 mm materials. Site counts for TSDs and BPDs on sample wafers show dislocations densities of 500 cm-2 and 300 cm-2, respectively. After CVD process optimization, a thickness uniformity (sigma/mean) of <1.5% and a doping uniformity of <13% was achieved on epitaxial layers on 150mm.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

Temperature control in a chemical reactor through variable area of the heat transfer surface. Simulation analysis

1982 ◽  
Vol 47 (2) ◽  
pp. 430-445
Author(s):  
Josef Horák ◽  
Zina Valášková
Keyword(s):  
Heat Exchange ◽  
Simulation Analysis ◽  
Batch Reactor ◽  
Chemical Reactor ◽  
Rate Of Change ◽  
Action Variable ◽  
Heat Exchange Surface ◽  
Relay With Hysteresis ◽  
Exchange Surface

An algorithm has been developed and on a mathematical model analyzed to stabilize the reaction temperature of a batch reactor. The reaction has been a zero-order one and the reactor has been operated in a instable operating point. The action variable is the heat exchange surface whose area is increased if the temperature is above, or decreased if the temperature is below the set point. The following two-point regulators have been studied: An ideal relay, a relay with hysteresis and an asymmetric PD relay. The effect has been discussed of the parameters of the regulators on the quality of regulation. Stability analysis has been made of the stationary switching cycles and the domains of applicability have been determined for individual regulators with respect to the rate of change of the area of heat exchange surface.

Nitrogen (N2) Implantation to Suppress Growth of Interfacial Oxide in Mocvd Bst and Sputtered Bst Films

1999 ◽  
Vol 567 ◽  
Author(s):  
Renee Nieh ◽  
Wen-Jie Qi ◽  
Yongjoo Jeon ◽  
Byoung Hun Lee ◽  
Aaron Lucas ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Interfacial Layer ◽  
Gate Dielectric ◽  
Nitrogen Concentration ◽  
Chemical Vapor ◽  
Future Generation ◽  
Oxide Thickness ◽  
Layer Growth ◽  
X Ray ◽  
Bst Films

ABSTRACTBa0.5Sr0.5TiO3 (BST) is one of the high-k candidates for replacing SiO2 as the gate dielectric in future generation devices. The biggest obstacle to scaling the equivalent oxide thickness (EOT) of BST is an interfacial layer, SixOy, which forms between BST and Si. Nitrogen (N2) implantation into the Si substrate has been proposed to reduce the growth of this interfacial layer. In this study, capacitors (Pt/BST/Si) were fabricated by depositing thin BST films (50Å) onto N2 implanted Si in order to evaluate the effects of implant dose and annealing conditions on EOT. It was found that N2 implantation reduced the EOT of RF magnetron sputtered and Metal Oxide Chemical Vapor Deposition (MOCVD) BST films by ∼20% and ∼33%, respectively. For sputtered BST, an implant dose of 1×1014cm−;2 provided sufficient nitrogen concentration without residual implant damage after annealing. X-ray photoelectron spectroscopy data confirmed that the reduction in EOT is due to a reduction in the interfacial layer growth. X-ray diffraction spectra revealed typical polycrystalline structure with (111) and (200) preferential orientations for both films. Leakage for these 50Å BST films is on the order of 10−8 to 10−5 A/cm2—lower than oxynitrides with comparable EOTs.

Microscopic FCA System for Depth-Resolved Carrier Lifetime Measurement in SiC

2018 ◽  
Vol 924 ◽  
pp. 269-272 ◽  
Author(s):  
Shinichi Mae ◽  
Takeshi Tawara ◽  
Hidekazu Tsuchida ◽  
Masashi Kato
Keyword(s):  
Carrier Lifetime ◽  
Laser Light ◽  
Probe Laser ◽  
Free Carrier Absorption ◽  
Cross Sectional ◽  
Lifetime Measurements ◽  
Control Distribution ◽  
System A ◽  
Excitation Laser ◽  
Carrier Absorption

For high voltage SiC bipolar devices, carrier lifetime is an important parameter, and for optimization of device performance, we need to control distribution of the carrier lifetime in a wafer. So far, there have been limited systems for depth-resolved carrier lifetime measurements without cross sectional cut. In this study, we adopted a free carrier absorption technique and made local overlapping of the probe laser light with excitation laser light to develop depth-resolved carrier lifetime measurements. We named the developed system a microscopic FCA system and demonstrated measurement results for samples with and without intentional carrier lifetime distribution.

Defect Generation and Annihilation in 3C-SiC-(001) Homoepitaxial Growth by Sublimation

2013 ◽  
Vol 740-742 ◽  
pp. 283-286
Author(s):  
Philip Hens ◽  
Julian Müller ◽  
Günter Wagner ◽  
Rickard Liljedahl ◽  
Erdmann Spiecker ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Structural Defects ◽  
Silicon Substrates ◽  
Growth Step ◽  
Planar Defects ◽  
Defect Generation ◽  
Defect Clusters ◽  
Homoepitaxial Growth ◽  
Cubic Silicon Carbide ◽  
Thick Layers

In this paper we present a concept on the defect generation and annihilation during the homoepitaxial growth step of cubic silicon carbide by sublimation epitaxy on templates grown by chemical vapor deposition on silicon substrates. Several structural defects like stacking faults, twins and star defects show opposite evolution from the template layer into the sublimation grown material. While single planar defects tend to annihilate with increasing layer thickness, the defect clusters assigned to the star defects are enlarging. These issues contribute to a balance of how to achieve the best possible quality on thick layers.

scholarly journals Structural and Magnetic Properties of Ni81Fe19Thin Film Grown on Si(001) Substrate via Single Graphene Layer

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Gui-fang Li ◽  
Shibin Liu ◽  
Shanglin Yang ◽  
Yongqian Du
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Vapor Deposition ◽  
Graphene Layer ◽  
Structural Investigation ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Magnetic Thin Films ◽  
Structural And Magnetic Properties

We prepared magnetic thin films Ni81Fe19on single-crystal Si(001) substrates via single graphene layer through magnetron sputtering for Ni81Fe19and chemical vapor deposition for graphene. Structural investigation showed that crystal quality of Ni81Fe19thin films was significantly improved with insertion of graphene layer compared with that directly grown on Si(001) substrate. Furthermore, saturation magnetization of Ni81Fe19/graphene/Si(001) heterostructure increased to 477 emu/cm3with annealing temperatureTa=400°C, which is much higher than values of Ni81Fe19/Si(001) heterostructures withTaranging from 200°C to 400°C.

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