What is GaAs?

GaAs(Gallium arsenide) is a compound semiconductor material,a mixture of two elements, gallium (Ga) and arsenic (As). The uses of Gallium arsenide are varied and include being used in LED/LD, field-effect transistors (FETs), and integrated circuits (ICs).

GaAs Basic Parameters at 300K

Crystal structure	Zinc Blende
Group of symmetry	Td2-F43m
Number of atoms in 1 cm3	4.42·1022
de Broglie electron wavelength	240 A
Debye temperature	360 K
Density	5.32 g cm-3
Dielectric constant (static )	12.9
Dielectric constant (high frequency)	10.89
Effective electron mass me	0.063mo
Effective hole masses mh	0.51mo
Effective hole masses mlp	0.082mo
Electron affinity	4.07 eV
Lattice constant	5.65325 A
Optical phonon energy	0.035 eV

GaAs Electrical Parameters

Breakdown field	≈4·105 V/cm
Mobility electrons	≤8500 cm2 V-1s-1
Mobility holes	≤400 cm2 V-1s-1
Diffusion coefficient electrons	≤200 cm2/s
Diffusion coefficient holes	≤10 cm2/s
Electron thermal velocity	4.4·105 m/s
Hole thermal velocity	1.8·105m/s

And now we introduce types of uses of GaAs based devices:

Types and Uses of GaAs Electronic Devices
Electronic devices	Material(layer/substrate)	Application	Technology Tends	Material Required
Digital IC	GaAs/GaAs	Ultra-high-speed computers	High level of integration
(MESFETHEMT)	GaAlAs/GaAs	PC,ATM,Image Processing	Low operating voltage
Microvave Devices	GaAs/GaAs	Mobile communications, satellite broadcasting	High power, low noise,	Low cost
(MESFETHEMT,	GaAlAs/GaAs	Low-noise receiver, amplified	High level of integration	Large diameter
Simulation	GaAlAs/InGaAs/GaAs	Automotive anti-collision system	Low operating voltage	Low Vth
ICMMICHBT)	InGaP/GaAs/GaAs	PAR
Hall devices	GaAs/GaAs	Auto VTR、	High sensitivity	Low cost,large diameter
		FDD sensors
		Position detection sensor
Types and Uses of GaAs Optoelectronic Devices
Optoelectronic devices	Material(layer/substrate)	Application	Technology Tends	Material Required
Visible Light LED	GaAsP/GaAs( red )                       GaAlAs/GaAs(high brightness red)   InGaAlP/GaAs(high brightness  orange/yellow)	Home appliances, DA, electronic equipment	High brightness	Low costs
		Car lights	Short wavelength	Large diameter
		Lights in fax
IR LED	GaAs/GaAs                                        GaAlAs/GaAs	Home appliances,DA
		machinery in Electronics industry	High power
		Remote control and optocoupler
		Optical circuit breaker
Semiconductor Laser	GaAs/GaAs	Optical communication switch
Short Wavelength LD	GaAlAs/GaAs(780nm)          InGaAlP/GaAs(680～630nm)	Light-emitting devices for Optical LAN,light emitting devices for testing equipments,CD,MD,Laser printer,CD-Rom,DVD-Rom,DVD-RAM	High Power,high level of integration,low wavelength	Low density,large diameter,low cost
Solar Cell	GaAs/GaAs	Satellite broadcasting, communications,Unmanned meteorological stations

What is GaN?

GaN(Gallium nitride), which is a compound semiconductor,it is a hard, high melting point materials, the melting point of about 1700 ° C, GaN is a high degree of ionization of III-Vcompound (0.5 or 0.43). At atmospheric pressure, the GaN crystal is generally hexagonal wurtzite structure. In a cell four atoms, the atomic volume is about half that of the GaAs. GaN is Non-Toxic.

Basic Parameters for Wurtzite crystal structure at 300K:

Breakdown field	~5 x 106 V cm-1
Mobility electrons	=< 1000 cm2 V-1 s-1
Mobility holes	=< 200 cm2 V-1 s-1
Diffusion coefficient electrons	25 cm2 s-1
Diffusion coefficient holes	5 cm2 s-1
Diffusion coefficient holes	2.6 x 105 m s-1
Diffusion coefficient holes	9.4 x 104 m s-1
Breakdown field	3.3 x 106 V cm-1
Conductivity σ	6÷12 Ω-1 cm-1
Mobility electrons μn	=< 440 cm2 V-1 s-1

Physical properties:

GaN is  stable bandgap semiconductor material with heat capacity and thermal conductivity.It can be deposited in thin film on sapphire or SiC. GaN can de doped with silicon or undoped to n-type and with magnesium to p-type. 

Growth Methods:

GaN substrate is grown by MBE,MOCVD, HVPE.

Types:

Freestanding GaN; GaN epitaxy onsapphire or SiC

Application:

It can be used to emit brilliant light in the form of light emitting diodes (LEDs) and laser diodes, as well as being the key material for next generation high frequency, high power transistors capable of operating at high temperatures.For example, GaN is the substrate which makes violet (405 nm) laser diodes possible, without use of nonlinear optical frequency-doubling. 

Manufacturer for reference:

PAM-XIAMEN is the world’s leading developer of solid-state lighting technology,he offer a full line: Freestanding GaN, GaN epitaxy on Sapphire.GaN based epitaxial wafer (LED Wafer) for LED.

SORAA:produce GaN on GaN LEDs

PAM-XIAMEN Offers Larger Free-Standing Semi-Insulating GaN Substrates

Xiamen Powerway Advanced Material Co.,Ltd., a leading supplier of ultra-high purity crystalline gallium nitride (GaN) and aluminum gallium nitride (AlGaN) materials and other related products and services announced the new availability of 2" size native semi-insulating GaN (SI GaN) substrates,which is on mass production in 2011. This new product represents a natural addition to PAM-XIAMEN's native SI GaN substrate product line, which also includes 10mm x 10mm,25mm x 25mm and 38mm x 38mm substrates.
Dr. Shaka, said, "We are pleased to offer larger native SI gallium nitride(GaN) to our customers including many who are developing better and more reliable high frequency high power GaN transistors. Our 50mm dia.native SI GaN product has excellent resistivity properties just like our smaller SI GaN substrates, as corroborated by recent electrical resistivity mapping measurements carried out. The larger size and availability improve our native SI GaN boule growth and wafering processes." and "Our customers can now benefit from the increased device yield expected when developing advanced transistors on a larger square substrate. Our larger square SI GaN substrates are natural by products of our ongoing efforts,  currently we are devoted to continuously develop round three-inch and four-inch native SI GaN substrates."
PAM-XIAMEN's improved SI GaN product line has benefited from strong tech. support from Native University and Laboratory Center.

About Xiamen Powerway Advanced Material Co., Ltd

Found in 1990,Xiamen Powerway Advanced Material Co., Ltd (PAM-XIAMEN) is a leading manufacturer of compound semiconductor material in China. PAM-XIAMEN develops advanced crystal growth and epitaxy technologies, manufacturing processes, engineered substrates and semiconductor devices. PAM-XIAMEN's technologies enable higher performance and lower cost manufacturing of semiconductor wafer.
In 2001,PAM-XIAMEN has been involved in GaN research.In 2009,PAM-XIAMEN has been mass production for GaN epitaxy on Sapphire and freestanding GaN single crystal wafer substrate which is for UHB-LED and LD. Grown by hydride vapour phase epitaxy (HVPE) technology,PAM-XIAMEN's GaN wafer has low defect density and less or free macro defect density.Currently PAM-XIAMEN can offer low defect density native (free-standing) GaN in customer-defined orientation including polar (c-plane Ga-face or N-face) and non-polar (a-plane and m-plane), GaN and AlN templates grown on sapphire and Si or SiC substrates, and ultra-high purity polycrystalline GaN.

About GaN

GaN(Gallium nitride), which is a compound semiconductor, it is a hard, high melting point materials, the melting point of about 1700 ° C, GaN is a high degree of ionization of III-Vcompound (0.5 or 0.43). At atmospheric pressure, the GaN crystal is generally hexagonal wurtzite structure. In a cell four atoms, the atomic volume is about half that of the GaAs. If you need more information about GaN, please visit: http://www.powerwaywafer.com/What-is-GaN.html 

PAM-XIAMEN Offers InGaN Substrates

Xiamen Powerway Advanced Material Co.,Ltd (PAM-XIAMEN), the leading developer and supplier of compound semiconductor crystal and wafer, today announces availability of InGaN substrate materials. InGaN is the key compound semiconductor material used for the fabrication of blue, green, and white light emitting diodes (LEDs),GaN-based ultra violet (UV), bblue laser diodes (LDs) and solar photovoltaic application. Indium gallium nitride is as the light-emitting layer for these light-emitting devices and determine device efficiency, light output power and lifetime. InGaN substrates are needed for InGaN-based device epitaxial structures and to improve device performance.

“Our success of  the InGaN material expend our nitride business,and move forward to the LED and solid-state lighting market fastly,” said Dr. Shaka “Now we are second manfuacturer to offer InGaN template after TDI,we will continue to offer this material to our current customers for green light LED application, our continuous research would focus on solid state lighting application,of course we will expend new customers for other application.”

“Now we can offer wide range nitirde semiconductor materials,including GaN, InGaN, InN, and AlN epi wafer with a wide range of deposition rates, various doping levels, wide composition ranges, and low defect densities, to meet our various customer's requests,including researcher and device foundry",added Victor Chan, a senior marketing manager for the company.

The Product

New substrates consist of an InGaN layer deposited on 2-inch GaN/sapphire template. In content in the InGaN layers ranges from 10 % to 40 %. Targeted applications are high brightness UV, blue, and green light emitting devices including light emitting diodes and, potentially, blue and green laser diodes. Currently InGaN template substrates are available in limited quantities. Available InGaN thickness:100-300nm.

Crystal Quality:Our side technology sector to the XRD data of a reference in InGaN as follows: (4um of GaN growth on the Template InGaN)

50nm InGaN, 20% In composition, the rocking curve FMHW (00.2) ~ 460 arcsecs (10.2) to 610 arcsecs(Test equipment is a Bruker D8 high-resolution X-ray diffraction).But please note that of InGaN XRD data strongly depends on the thickness, the thickness of 200nm, of InGaN crystalline quality would be higher.Though the Raman data is also a measure of crystal quality, but less accuracy than the XRD precision, so we generally measure the quality of the crystal without Raman test.

Crystal Structure:

InGaN  100nm-300nm  

4um GaN  4um  

Sapphire  430um 

Crystal Picture:

http://www.powerwaywafer.com/data/article/1345598521738840718.jpg

 

About Xiamen Powerway Advanced Material Co., Ltd

 

Found in 1990,Xiamen Powerway Advanced Material Co., Ltd (PAM-XIAMEN) is a leading manufacturer of compound semiconductor material in China. PAM-XIAMEN develops advanced crystal growth and epitaxy technologies, manufacturing processes, engineered substrates and semiconductor devices. PAM-XIAMEN's technologies enable higher performance and lower cost manufacturing of semiconductor wafer.

In 2001,PAM-XIAMEN has been involved in GaN material research.PAM-XIAMEN now offer  GaN, InGaN, InN, and AlN epitaxial products with a wide range of deposition rates, various doping levels, wide composition ranges, and low defect densities.

If you need more information about InGaN, please visit: http://www.powerwaywafer.com/GaN-Templates.html