AlGaN/GaN high electron mobility transistors on Si(111) substrates

AlGaN/GaN high electron mobility transistors (HEMTs) on silicon substrates have for the first time been realized using organometallic vapor phase epitaxy (OMVPE). Using 1 /spl Omega/-cm p-Si(111), these devices exhibited static output characteristics with low output conductance and isolation approaching 80 V. Under microwave rf operation, the substrate charge becomes capacitively coupled and parasitically loads these devices thereby limiting their performance. As a result, typical 0.3 /spl mu/m gate length devices show a 25 GHz cutoff frequency, with near unity f/sub max//f/sub T/ ratio and 0.55 W/mm output power. A small-signal equivalent circuit incorporating elements representing the parasitic substrate loading accurately models the measured S-parameters. Removal of the conductive substrate is one way to effectively eliminate this parasitic loading. Through backside processing, freestanding 0.4-mm HEMT membranes with no thermal management were demonstrated and exhibited a significant improvement in their f/sub max//f/sub T/ ratio up to 2.5 at the cost of lower f/sub T/ and f/sub max/ along with an almost four-fold reduction of I/sub dss/.

[1]  L. Eastman,et al.  The effect of surface passivation on the microwave characteristics of undoped AlGaN/GaN HEMTs , 2000, IEEE Electron Device Letters.

[2]  W. Richter,et al.  Epitaxial growth of AlN and GaN on Si(1 1 1) by plasma-assisted molecular beam epitaxy , 1999 .

[3]  James R. Shealy,et al.  Microwave performance of AlGaN/GaN metal insulator semiconductor field effect transistors on sapphire substrates , 2001 .

[4]  R. Gaska,et al.  Visible-blind GaN Schottky barrier detectors grown on Si(111) , 1998 .

[5]  P. Schmid,et al.  Large signal frequency dispersion of AlGaN/GaN heterostructure field effect transistors , 1999 .

[6]  Vincenzo Fiorentini,et al.  MACROSCOPIC POLARIZATION AND BAND OFFSETS AT NITRIDE HETEROJUNCTIONS , 1998 .

[7]  James S. Speck,et al.  Structural and optical properties of GaN laterally overgrown on Si(111) by metalorganic chemical vapor deposition using an AlN buffer layer , 1999 .

[8]  K. Doverspike,et al.  High-power microwave GaN/AlGaN HEMTs on semi-insulating silicon carbide substrates , 1999, IEEE Electron Device Letters.

[9]  Michael S. Shur,et al.  Current/voltage characteristic collapse in AlGaN/GaN heterostructure insulated gate field effect transistors at high drain bias , 1994 .

[10]  David Vanderbilt,et al.  Spontaneous polarization and piezoelectric constants of III-V nitrides , 1997 .

[11]  Isamu Akasaki,et al.  The growth of single crystalline GaN on a Si substrate using AIN as an intermediate layer , 1993 .

[12]  Lester F. Eastman,et al.  A 0.1- mu m gate Al/sub 0.5/In/sub 0.5/As/Ga/sub 0.5/In/sub 0.5/As MODFET fabricated on GaAs substrates , 1988 .

[13]  O. Ambacher,et al.  High electron mobility AlGaN/GaN heterostructure on (111) Si , 2000 .

[14]  D. Follstaedt,et al.  Microstructure of GaN Grown on (111) Si by MOCVD , 1999 .

[15]  P. J. Tasker,et al.  Bias dependence of the MODFET intrinsic model elements values at microwave frequencies , 1989 .

[16]  Supratik Guha,et al.  Ultraviolet and violet GaN light emitting diodes on silicon , 1998 .

[17]  Lester F. Eastman,et al.  AlGaN/GaN heterostructures on insulating AlGaN nucleation layers , 1999 .

[18]  J. Shealy,et al.  Microwave performance of AlGaN/GaN metal insulator semiconductor field effect transistors , 2000, International Electron Devices Meeting 2000. Technical Digest. IEDM (Cat. No.00CH37138).

[19]  R. Dimitrov,et al.  Two dimensional electron gases induced by spontaneous and piezoelectric polarization in undoped and doped AlGaN/GaN heterostructures , 2000 .

[20]  Josef Zweck,et al.  Structural properties of AlGaN/GaN heterostructures on Si(111) substrates suitable for high-electron mobility transistors , 2000 .

[21]  Jaime A. Freitas,et al.  Observation of deep traps responsible for current collapse in GaN metal-semiconductor field-effect transistors , 1999 .