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Lin G.-B.,Rensselaer Polytechnic Institute | Zhang X.,Veeco MOCVD Operations | Lee S.M.,Veeco MOCVD Operations | Papasouliotis G.,Veeco MOCVD Operations | And 3 more authors.
Current Applied Physics | Year: 2015

Light-emitting diodes (LEDs) with a Mg-doped p-type Ga1-xInxN (0x 0.07) spacer layer located between an undoped GaN spacer layer and the electron blocking layer are investigated. The LEDs are found to have comparable peak efficiency but less efficiency droop when the crystal quality of the p-type Ga1-xInxN spacer layer is well-controlled by lowering the growth temperature and by using a suitable In composition and Mg doping concentration. All LED samples with the p-type spacer layer show a smaller efficiency droop compared to a reference LED having an undoped GaN spacer. Among the sample sets investigated, an optical power enhancement of 12% at 111 A/cm2 is obtained when inserting a 5 nm-thick p-type Ga0.97In0.03N spacer layer. The results support that carrier transport is the key factor in the efficiency droop observed in GaN-based LEDs. © 2015 Elsevier B.V.All rights reserved. Source


Papasouliotis G.D.,Veeco MOCVD Operations | Su J.,Veeco MOCVD Operations | Krishnan B.,Veeco MOCVD Operations | Arif R.,Veeco MOCVD Operations
ECS Transactions | Year: 2015

We are reporting on the epitaxial growth of Al/Ga/N films on 200 mm Si substrates carried out in Veeco's Propel" rotating disk, single wafer, vertical MOCVD reactor. The Turbodisc® reactor is designed for uniform alkyl and hydride flow distribution, and temperature profile, resulting in uniform and concentrically symmetric epilayer thickness and chemical composition. Results are presented on film stress and wafer curvature control facilitated by adjusting the thickness and growth conditions of individual layers in AlN/GaN superlattices. The growth of highly resistive, intrinsically carbon-doped GaN layers is studied, and the influence of growth conditions, growth temperature, pressure, and V/III ratio, on carbon incorporation rate, crystal quality, and surface morphology will be discussed in this paper. Carbon incorporation is enhanced at lower growth temperature, lower pressure, and lower V/III ratios; we have obtained concentrations as high as 3E19/cm at a growth pressure of 35 Torr and growth temperature of 960°C. © The Electrochemical Society. Source


Su J.,Veeco MOCVD Operations | Krishnan B.,Veeco MOCVD Operations | Paranjpe A.,Veeco MOCVD Operations | Papasouliotis G.D.,Veeco MOCVD Operations
CS MANTECH 2014 - 2014 International Conference on Compound Semiconductor Manufacturing Technology | Year: 2014

The influence of MOCVD growth conditions (carrier gas, growth temperature, and V/III ratio) on the AlGaN barrier and the corresponding 2DEG for AlGaN/GaN heterostructures grown on 150 mm silicon is investigated. Hall mobility 2200 cm2/V.s, with sheet carrier concentration 8.7e1012 cm-2 and sheet resistance 326 Ohm/sq, is obtained for AlGaN grown in N2 ambient and with high V/III ratios. Source


Lee D.S.,Veeco MOCVD Operations | Su J.,Veeco MOCVD Operations | Krishnan B.,Veeco MOCVD Operations | Papasouliotis G.D.,Veeco MOCVD Operations | Paranjpe A.,Veeco MOCVD Operations
ECS Transactions | Year: 2013

Growth of crack-free AlGaN/GaN heterostructures on 6 and 8 inch Si(111) by 5×6″ and 3×8″ multi-wafer K465i production MOCVD system is presented. The two-dimensional-electron-gas is formed at the AlGaN/GaN interface with average Hall mobility values more than 1800 cm2/v.s and sheet resistance less than 400 Ohm/sq. Run to run repeatability of AlGaN/GaN structural qualities, wafer bow, and 2DEG properties show the potential manufacturing possibility with the epitaxial process stability and longevity. © The Electrochemical Society. Source


Su J.,Veeco MOCVD Operations | Armour E.A.,Veeco MOCVD Operations | Krishnan B.,Veeco MOCVD Operations | Lee S.M.,Veeco MOCVD Operations | Papasouliotis G.D.,Veeco MOCVD Operations
Materials Research Society Symposium Proceedings | Year: 2015

Stress control using AIN/GaN superlattices (SLs) for epitaxy of GaN on 200 mm Si (111) substrates is reported. Crack-free 2 μm GaN layers were grown over structures containing 50 to 100 pairs of 3-5 nm A1N/10-30 nm GaN SLs. Compressive and tensile stress can be precisely adjusted by changing the thickness of the A1N and GaN layers in the SLs. For a constant period thickness, the effects of growth conditions, such as growth rate of GaN, V/III ratio during A1N growth, and growth temperature, on wafer stress were investigated. © 2015 Materials Research Society. Source

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