Influence of AlN spacer on the properties of AlGaN/AlN/GaN heterostructures

• Autorzy: Wosko M , Paszkiewicz B , Paszkiewicz R , Tlaczala M
• Języki publikacji: EN

Abstrakty

EN

AlGaN/GaN heterostructures attract attention of many research groups over the last decade because of their superior properties (high mobility and saturation velocity of 2DEG) and strong capability in high frequency/power electronics and sensors applications. One of the factors which reduces the mobility of two-dimensional electron gas (2DEG) is the alloy and interface roughness scattering mechanism occurring at the heterointerface. Mathematical calculations of a wave-function of 2DEG in the channel show that theses two phenomena play an important role, due to the fact that some electrons in 2DEG can migrate into AlGaN barrier and be strongly dissipated. One of the proposed solutions against alloy scattering in the buffer layer is the use of thin AlN spacer at the heterointerface between AlGaN and GaN layers. AlN layer enhances the conduction band offset due to a polarization-induced dipole in the AlN layer, and therefore increases carrier confinement. Several Al0.18GaN0.82/AlN/GaN heterostructures with different AlN spacer layer thickness were grown by MOVPE method for studies of the Hall mobility and sheet carrier concentration of 2DEG. Hall measurements performed using Van der Pauw shown mobility maximum at nominally 1.3 nm AlN spacer thickness and almost linear dependence of sheet carrier concentration with AlN spacer thickness in the range from 0.7 to 2 nm.

Słowa kluczowe

EN

AlGaN/GaN; heterostructure; AlN spacer; MOVPE

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Optica Applicata
• Rocznik: 2013
• Tom: Vol. 43, nr 1
• Strony: 61--66
• Opis fizyczny: Bibliogr. 15 poz., rys., tab., wykr.

Twórcy

autor

Wosko M

• Faculty of Microsystem Electronics and Photonic, Wrocław University of Technology, Janiszewskiego 11/17, 50-372 Wrocław, Poland

autor

Paszkiewicz B

autor

Paszkiewicz R

autor

Tlaczala M

Bibliografia

• [1] JOHNSON E.O., Physical limitation on frequency and power parameters of transistors, IRE International Convention Record, Vol. 13, 1965, pp. 27–34.
• [2] XING H.G., DORA Y., CHINI A., HEIKMAN S.J., KELLER S., MISHRA U.K., High breakdown voltage AlGaN-GaN HEMTs achieved by multiple field plates, IEEE Electron Device Letters 25(4), 2004, pp. 161–163.
• [3] TIPIRNENI N., KOUDYMOV A.N., ADIVARAHAN V., JIN-WEI W. YANG, SIMIN G.S., KHAN M.A., The 1.6-kV AlGaN/GaN HFETs, IEEE Electron Device Letters 27(9), 2004, pp. 716–718.
• [4] ESTMAN L.F., TILAK V., SMART J.A., GREEN B.M., CHUMBES E.M., DIMITROV R., HYUNGTAK KIM, AMBACHER O.S., WEIMANN N.G., PRUNTY T., MURPHY M.J., SCHAFF W.J., SCHEALY J.R., Undoped AlGaN/GaN HEMTs for microwave power amplification, IEEE Transactions on Electron Devices 48(3), 2001, pp. 479–485.
• [5] IBBETSON J.P., FINI P.T., NESS K.D., DENBAARS S.P., SPECK J.S., MISHRA U.K., Polarization effects, surface states, and the source of electrons in AlGaN/GaN heterostructure field effect transistors, Applied Physics Letters 77(2), 2000, pp. 250–252.
• [6] YIFEI ZHANG, SINGH J., Charge control and mobility studies for an AlGaN/GaN high electron mobility transistor, Journal of Applied Physics 85(1), 1999, pp. 587–594.
• [7] SYED S., MANFRA M.J., WANG Y.J., MOLNAR R.J., STOLMAR H.L., Electron scattering in AlGaN/GaN structures, Applied Physics Letters 84(9), 2004, pp. 1507–1509.
• [8] KATZ O., HORN A., BAHIR G., SALZMAN J., Electron mobility in an AlGaN/GaN two-dimensional electron gas. I. Carrier concentration dependent mobility, IEEE Transactions on Electron Devices 50(10), 2003, pp. 2002–2008 .
• [9] YIFEI ZHANG, SMORCHKOVA I.P., ELSASS C.R., KELLER S., IBBETSON J.P., DENBAARS S., MISHRA U.K., SINGH J., Charge control and mobility in AlGaN/GaN transistors: experimental and theoretical studies, Journal of Applied Physics 87(11), 2000, pp. 7981–7987.
• [10] GRUNDMANN M., “BandEng” Poisson–Schrödinger solver software, available online http://my.ece.ucsb.edu/mgrundmann/bandeng/
• [11] PASZKIEWICZ B., WOSKO M., PASZKIEWICZ R., TLACZALA M., 14th European Workshop on Metalorganic Vapor Phase Epitaxy, EW-MOVPE XIV: extended abstracts, June 5–8, 2011, pp. 193–196.
• [12] HUBBARD S.M., ZHAO G., PAVLIDIS D., SUTTON W., CHO E., High-resistivity GaN buffer templates and their optimization for GaN-based HFETs, Journal of Crystal Growth 284(3–4), 2005, pp. 297–305.
• [13] XU F.J., XU J., SHEN B., MIAO Z.L., HUANG S., LU L., YANG Z.J., QIN Z.X., ZHANG G.Y., Realization of high-resistance GaN by controlling the annealing pressure of the nucleation layer in metal--organic chemical vapor deposition, Thin Solid Films 517(2), 2008, pp. 588–591.
• [14] WICKENDEN A.E., KOLESKE D.D., HENRY R.L., TWIGG M.E., FATEMI M., Resistivity control in unintentionally doped GaN films grown by MOCVD, Journal of Crystal Growth 260(1–2), 2004, pp. 54–62.
• [15] WEI ZHAO, JENA D., Dipole scattering in highly polar semiconductor alloys, Journal of Applied Physics 96(4), 2004, pp. 2095–2101.