Nitrogen Plasma Pretreatment of Sapphire Substrates for the GaN Buffer Growth by Remote Plasma Enhanced MOCVD

1996 ◽  
Vol 449 ◽  
Author(s):  
Min Hong Kim ◽  
Cheolsoo Sone ◽  
Jae Hyung Yi ◽  
Soun Ok Heur ◽  
Euijoon Yoon
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Nitrogen Plasma ◽  
Layer Growth ◽  
Buffer Layers ◽  
Rf Power ◽  
Remote Plasma ◽  
Sapphire Substrates ◽  
Nucleation Sites ◽  
Plasma Pretreatment

ABSTRACTLow-temperature GaN buffer layers with smooth surfaces and high crystallinity could be prepared by a remote plasma enhanced metalorganic vapor deposition after the pretreatment of substrates with rf nitrogen plasma. Smooth AIN thin layer was formed on the (0001) sapphire substrate by the nitrogen plasma pretreatment for an hour. The AIN layer provided the nucleation sites for the subsequent buffer layer growth, thus highly preferred (0001) GaN buffer layers could be grown on the pretreated substrate. Formation of the AIN layer on sapphire and the surface smoothness were affected by pretreatment parameters such as exposure time, temperature, and rf power.

Low-Temperature Metalorganic Chemical Vapor Deposition of Gallium Nitride on (0001) Sapphire Substrates Using a Remote rf Nitrogen Plasma

1996 ◽  
Vol 449 ◽  
Author(s):  
Cheolsoo Sone ◽  
Min Hong Kim ◽  
Jae Hyung Yi ◽  
Soun Ok Heur ◽  
Euijoon Yoon
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Nitrogen Plasma ◽  
Structural Quality ◽  
Organic Chemical ◽  
Rf Power ◽  
Sapphire Substrates ◽  
Metal Organic

ABSTRACTWe report the low-temperature growth of GaN layers on (0001) sapphire substrates by a remote plasma enhanced metal-organic chemical vapor deposition in the temperature range of 500 - 800 $C. Effects of process parameters on the growth of GaN were studied. The structural quality of GaN improved as the growth temperature increased and the rf power decreased. Highly oriented GaN layers could be deposited at fairly low temperatures such as 500 $C under low rf power with low growth rate conditions.

Nitridation Of Sapphire Substrate Using Remote Plasma Enhanced-Ultrahigh Vacuum Chemical Vapor Deposition At Low Temperature

1997 ◽  
Vol 482 ◽  
Author(s):  
Jong-Sik Paek ◽  
Kyoung-Kook Kim ◽  
Ji-Myon Lee ◽  
Dong-Jun Kim ◽  
Hyo-Gun Kim ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Sapphire Substrate ◽  
Vapor Deposition ◽  
Ultrahigh Vacuum ◽  
Chemical Vapor ◽  
Rf Power ◽  
Remote Plasma ◽  
Sapphire Surface ◽  
Nitridation Process

AbstractA remote plasma enhanced-ultrahigh vacuum chemical vapor deposition (RPE-UHVCVD) system equipped with a radio frequency-inductively coupled plasma (RF-ICP) which produces the reactive nitrogen species was employed to study the nitridation process at low temperature. The sapphire surface nitridated under various conditions was investigated with x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The nitridation process seems to be mostly affected by the RF power even at low temperature since the intensity of the N1s, peak was not dependent on the substrate temperature but on the RF power. The AFM images showed that the protrusion density on the sapphire surface decreased rapidly when the nitridation temperature was decreased. This result suggests that the formation of the protrusions is closely related to the process temperature, indicating that the formation of such protrusions is caused by the change of an elastic strain energy due to the thermal stress. It was possible to nitridate the sapphire surface without protrusion at a very low temperature. The crystallinity of GaN grown at 450 °C was found to be much improved when the sapphire substrate was nitridated at low temperature prior to the GaN layer growth.

Epitaxial GaN Layer Growth Using Nitrogen Enriched TiN Buffer Layers

2006 ◽  
Vol 916 ◽  
Author(s):  
Kazuhiro Ito ◽  
Yu Uchida ◽  
Sang-jin Lee ◽  
Susumu Tsukimoto ◽  
Yuhei Ikemoto ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Light Emission ◽  
Chemical Vapor ◽  
Nucleation Site ◽  
Layer Growth ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Nitrogen Enrichment ◽  
Threading Dislocation ◽  
Sapphire Substrates

AbstractAbout 20 years ago, the discovery of an AlN buffer layer lead to the breakthrough in epitaxial growth of GaN layers with mirror-like surface, using a metal organic chemical vapor deposition (MOCVD) technique on sapphire substrates. Since then, extensive efforts have been continued to develop a conductive buffer layer/substrate for MOCVD-grown GaN layers to improve light emission of GaN light-emitting diodes. In the present study, we produced MOCVD-grown, continuous, flat epitaxial GaN layers on nitrogen enriched TiN buffer layers with the upper limit of the nitrogen content of TiN deposited at room temperature (RT) on sapphire substrates. It was concluded that the nitrogen enrichment would reduce significantly the TiN/GaN interfacial energy. The RT deposition of the TiN buffer layers suppresses their grain growth during the nitrogen enrichment and the grain size refining must increase nucleation site of GaN. In addition, threading dislocation density in the GaN layers grown on TiN was much lower than that in the GaN layers grown on AlN.

Low-temperature Si in-situ cleaning and homoepitaxy by remote plasma-enhanced chemical vapor deposition

1990 ◽  
Author(s):  
Ting-Chen Hsu ◽  
Brian G. Anthony ◽  
Louis H. Breaux ◽  
Rong Z. Qian ◽  
Sanjay K. Banerjee ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Remote Plasma

scholarly journals Effect of Buffer Layer and III/V Ratio on the Surface Morphology of Gan Grown by MBE

1999 ◽  
Vol 4 (S1) ◽  
pp. 417-422 ◽  
Author(s):  
E. C. Piquette ◽  
P. M. Bridger ◽  
R. A. Beach ◽  
T. C. McGill
Keyword(s):  
Surface Morphology ◽  
Buffer Layer ◽  
Flux Ratio ◽  
Plasma Source ◽  
Growth Conditions ◽  
Nitrogen Plasma ◽  
Layer Growth ◽  
Buffer Layers ◽  
Flat Surfaces ◽  
Aln Buffer

The surface morphology of GaN is observed by atomic force microscopy for growth on GaN and AlN buffer layers and as a function of III/V flux ratio. Films are grown on sapphire substrates by molecular beam epitaxy using a radio frequency nitrogen plasma source. Growth using GaN buffer layers leads to N-polar films, with surfaces strongly dependent on the flux conditions used. Flat surfaces can be obtained by growing as Ga-rich as possible, although Ga droplets tend to form. Ga-polar films can be grown on AlN buffer layers, with the surface morphology determined by the conditions of buffer layer deposition as well as the III/V ratio for growth of the GaN layer. Near-stoichiometric buffer layer growth conditions appear to support the flattest surfaces in this case. Three defect types are typically observed in GaN films on AlN buffers, including large and small pits and “loop” defects. It is possible to produce surfaces free from large pit defects by growing thicker films under more Ga-rich conditions. In such cases the surface roughness can be reduced to less than 1 nm RMS.

Remote Plasma-Enhanced Chemical Vapor Deposition of Epitaxial Silicon on Silicon (100) at 150°C

1989 ◽  
Vol 165 ◽  
Author(s):  
T. Hsu ◽  
B. Anthony ◽  
L. Breaux ◽  
S. Banerjee ◽  
A. Tasch
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Hydrogen Plasma ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ex Situ ◽  
Epitaxial Silicon ◽  
Remote Plasma ◽  
Silicon Epitaxy

AbstractLow temperature processing will be an essential requirement for the device sizes, structures, and materials being considered for future integrated circuit applications. In particular, low temperature silicon epitaxy will be required for new devices and technologies utilizing three-dimensional epitaxial structures and silicon-based heterostructures. A novel technique, Remote Plasma-enhanced Chemical Vapor Deposition (RPCVD), has achieved epitaxial silicon films at a temperature as low as 150°C which is believed to be the lowest temperature to date for silicon epitaxy. The process relies on a stringent ex-situ preparation procedure, a controlled wafer loading sequence, and an in-situ remote hydrogen plasma clean of the sample surface, all of which provide a surface free of carbon, oxygen, and other contaminants. The system is constructed using ultra-high vacuum technology (10-10 Torr) to achieve and maintain contaminantion-free surfaces and films. Plasma excitation of argon is used in lieu of thermal energy to provide energetic species that dissociate silane and affect surface chemical processes. Excellent crystallinity is observed from the thin films grown at 150°C using the analytical techniques of Transmission Electron Microscopy (TEM) and Nomarski interference contrast microscopy after defect etching.

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