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"/4” size AlGaN–GaN HEMTs Grown on Sapphire Substrates,which is on mass production in 2012.
XIAMEN,FUJIAN, CHINA., August 12, 2014 - (PressReleasePoint) -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"/4” size AlGaN–GaN HEMTs Grown on Sapphire Substrates,which is on mass production in 2012. And now PAM-XIAMEN give a example as follows:
2" GaN HEMT on Sapphire
Nucleation Layer: AlN
Buffer Layer: GaN (1800 nm)
Spacer: AlN (1nm)
Schottky Barrier: AlGaN (21 nm, 20%-30% Al)
Cap: GaN (1.5nm)
2DEG density:>10^13 cm-2 and Mobility>1600cm^2/vs.
RMS roughness(AFM):<0.5NM(5.0um x 5.0um scan area
Sheet resistivity: <200
About GaN hemt on sapphire
AlGaN–GaN HEMTs are promising candidates for highpower, high-frequency, and high-breakdown microwave device applications. However, III-V nitrides grown heteroepitaxially on planar sapphire substrates contain high-density dislocations
in the order of 10^8–10^10 cm^-2 , resulting from the large lattice and thermal expansion mismatch between the III-nitride and the substrate. The high-density dislocations adversely affect the device performance. Dislocation-related device characteristics include leakage current, breakdown voltage, frequency-related noise, and saturated drift velocity of carriers.
Currently, one of the main challenges to enhance RF performance of AlGaN–GaN HEMTs is to reduce the dislocation densities in the bulk and the surface of the AlGaN–GaN heterostructure. Various techniques such as AlGaN–GaN heterostructures over bulk GaN substrates, on AlN/sapphire templates, as well as epitaxial lateral overgrowth (ELO), have been developed for the reduction of GaN dislocation density. However, insulating bulk GaN substrates and AlN/sapphire templates were expensive and not commercially available. Although the ELO technique can effectively improve the crystalline quality of the overgrown layers, there are possible complications of the Si N or SiO patterned-mask on as-grown GaN, which also increases the growth and process time. Additional mask-related drawbacks of ELO include possibilities of impurity contamination and stress-induced tilt in the overgrown layer. GaN grown directly on patterned sapphire substrates is a much simpler means. We have used a maskless and single-step overgrowth technique in reducing the dislocation density and effectively improved the performance of blue LEDs.
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 higherperformance 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 AlNtemplates and multi-structure as HEMT structure grown on sapphire and Si or SiC substrates, and ultra-high purity polycrystalline GaN.