Fabrication of high performance GaN modulation doped field effect transistors

Bardwell, J. A.; Foulds, Ian G.; Lamontagne, B.; Tang, H.; Webb, J. B.; Marshall, Paul; Rolfe, S.; Stapledon, J.; MacElwee, T.W.

doi:10.1116/1.582172

Cited by 30 publications

(16 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Processing of the HFET structures has been described previously [13,14]. Briefly, the steps consisted of mesa isolation by chemically assisted ion beam etching, S-D ohmic contact metal deposition (Ti/Al/Ti/Au 20/100/45/55 nm) and rapid thermal annealing at 650 1C for 30 s in N 2 atmosphere, gate Schottky metal deposition (30 nm of sputtered Pt, for adhesion, followed by e-beam deposited Pt/Au 100/200 nm).…”

Section: Methodsmentioning

confidence: 99%

High-performance GaN/InGaN heterostructure FETs on Mg-doped GaN current blocking layers

Kuan

Chang

et al. 2004

Journal of Crystal Growth

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

High-performance GaN/InGaN heterostructure FETs on Mg-doped GaN current blocking layers

Kuan

Chang

et al. 2004

Journal of Crystal Growth

Self Cite

View full text Add to dashboard Cite

“…The Hall effect 2DEG sheet charge density and mobility were 1.8 Â 10 13 cm --2 and 879 cm 2 /Vs in the wafer center, respectively. A more complete description of the device fabrication was given elsewhere [10]. One quarter of the two-inch wafer was processed.…”

Section: Methodsmentioning

confidence: 99%

Surface Passivation of AlGaN/GaN HFETs Using AlN Layer Deposited by Reactive Magnetron Sputtering

Liu

Bardwell

McAlister

et al. 2002

phys. stat. sol. (c)

Self Cite

View full text Add to dashboard Cite

In this paper we show the characteristics of an AlGaN/GaN metal-insulator-semiconductor heterostructure field effect transistor (MISFET) which uses an AlN film as the gate insulator, a passivated MISFET with another layer of AlN over the gate, a regular AlGaN/GaN heterostructure field effect transistor (HFET) and an AlN passivated regular HFET. The AlN insulating layer was deposited by Reactive Magnetron Sputtering. The thickness of each AlN passivation layer is about 50 nm. The gate leakage currents for the MISFET, passivated MISFET, and passivated HFET were much smaller than that for the regular HFET. We observed the current collapse for the regular HFET and the passivated MISFET, unstable DC characteristics for the MISFET, and the suppression of the current collapse for the passivated HFET.1. Introduction GaN based wide band gap semiconductor materials have been intensively studied for applications in high temperature, high frequency, and high power electronics and significant progress has been made recently. However, there are still two main issues: the large gate leakage current [1] and current collapse [2] at high drain current or a high RF-input drive on the gate. To overcome these problems, it is essential to understand the the AlGaN/GaN heterostructure surface and to develop a suitable surface passivation process [3,4] In this letter, the comparative studies of an AlGaN/GaN MISFET which use an AlN film as the gate insulator, a passivated MISFET with another layer of AlN over the gate, a regular AlGaN/GaN HFET and an over-gate passivated HFET will be reported.

show abstract

“…Studies on contacts to AlGaN or AlGaN/GaN HFETs have been based on the Ti/Al, [7][8][9][10][11][12][13][14][15][16][17][18][19][20] NiAl, 21 and Pd/Al 7 metallization schemes with different overlayers for the ohmic contacts and on Ti, 22 Ni, [22][23][24] Pd, 25 Re, 26 Ir, 14,17,19 Pt, 16,25 Pt/Ti, 14 Au, [27][28][29] and WSiN 14 for the Schottky contacts. The choice of systems has been highly motivated by successful contact formation to GaN by these metallization schemes, and the studies have mainly been concerned with optimizing the electrical properties, i.e., low contact resistivity or high barrier heights, and thermal stability on nAl x Ga 1-x N with x ≤ 35%.…”

Section: Introductionmentioning

confidence: 99%

Phase equilibria in transition metal Al-Ga-N systems and thermal stability of contacts to AlGaN

Schweitz

Mohney

2001

Journal of Elec Materi

View full text Add to dashboard Cite

As a first step in predicting the phase equilibria in TM-Al-Ga-N systems, where TM denotes a transition metal from the first three transition series, phase equilibria are calculated in the TM-Al-N systems, and the condensed phases in equilibrium with both AlN and N 2 gas are discussed with respect to the position of the transition metal in the periodic table, temperature, and nitrogen pressure. Possible phases for use as stable electrical contacts to AlGaN are identified using these predictions, similar previous predictions for the TM-Ga-N systems and experimental findings. fraction increases, the electronic properties of the existing contacts change due to an increasing band gap and decreasing electron affinity of AlGaN, and new metallization schemes may have to be developed to accomplish good contact formation to Al x Ga 1-x N with x > 35%. New metallization schemes may also turn out to yield contacts to Al x Ga 1-x N with x ≤ 35% with superior properties to the existing contacts.The phase equilibria in the TM-Ga-N systems, where TM denotes a transition metal from the first three transition series, have previously been estimated. 30 As a first step in understanding the TM-AlGa-N systems, this article discusses the phase equilibria in the TM-Al-N systems. There are fortunately more experimentally available phase diagrams for these systems 31-42 than for the TM-Ga-N system; 30,43-47 however, many of the diagrams are not available for the conditions of most interest for processing contacts and devices. Thus, calculated ternary phase diagrams have to be used in many cases. Such an approach has been taken for systems composed of transition metals and Al-As, 48,50 In-P, 51,52 and In-As; 48,49 however, the same simple approach that has been used to calculate the ternary phase diagrams is not possible for the TM-Al-Ga-N systems due to lack of information about quarternary phases and the predominance of solution phases in the TM-Al-Ga and AlGa-N systems.This paper presents simple ternary phase diagram calculations of the TM-Al-N systems. These calcula-

show abstract

Fabrication of high performance GaN modulation doped field effect transistors

Cited by 30 publications

References 11 publications

High-performance GaN/InGaN heterostructure FETs on Mg-doped GaN current blocking layers

High-performance GaN/InGaN heterostructure FETs on Mg-doped GaN current blocking layers

Surface Passivation of AlGaN/GaN HFETs Using AlN Layer Deposited by Reactive Magnetron Sputtering

Phase equilibria in transition metal Al-Ga-N systems and thermal stability of contacts to AlGaN

Contact Info

Product

Resources

About