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in creator/contributor: "Wilson, R.G."

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III-Nitride ion implantation and device processing

Ion implantation doping and isolation has played a critical role in realizing high performance photonic and electronic devices in all mature semiconductor materials; this is also expected for binary III-Nitride materials (InN, GaN, AlN) and their alloys as epitaxy improves and more advanced device structures fabricated. This paper reports on recent progress in ion implantation doping of III-Nitride materials that has led to the first demonstration of a GaN JFET (junction field effect transistor… more

Date: June 1, 1996

Creator: Zolper, J. C.; Shul, R. J.; Baca, A. G.; Pearton, S. J.; Abernathy, C. R.; Wilson, R. G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

P- and N-type implantation doping of GaN with Ca and O

III-N photonic devices have made great advances in recent years following the demonstration of doping of GaN p-type with Mg and n-type with Si. However, the deep ionization energy level of Mg in GaN ({approximately} 160 meV) limits the ionized of acceptors at room temperature to less than 1.0% of the substitutional Mg. With this in mind, the authors used ion implantation to characterize the ionization level of Ca in GaN since Ca had been suggested by Strite to be a shallow acceptor in GaN. Ca-i… more

Date: May 1, 1996

Creator: Zolper, J. C.; Wilson, R. G.; Pearton, S. J. & Stall, R. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Effects of Hydrogen Implantation into GaN

Proton implantation in GaN is found to reduce the free carrier density through two mechanisms - first, by creating electron and hole traps at around Ec-0.8eV and Ev+0.9eV that lead to compensation in both n- and p-type material, and second, by leading to formation of (AH)O complexes, where A is any acceptor (Mg, Ca, Zn, Be, Cd). The former mechanism is usefid in creating high resistivity regions for device isolation, whereas the latter produces unintentional acceptor passivation that is detrime… more

Date: December 24, 1998

Creator: Abernathy, C.R.; Han, J.; Pearton, S.J.; Shul, R.J.; Song, C.Y.; Stavola, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultra High Temperature Rapid Thermal Annealing of GaN

All of the major acceptor (Mg, C, Be) and donor (Si, S, Se and Te) dopants have been implanted into GaN films grown on A1203 substrates. Annealing was performed at 1100- 1500 C, using AIN encapsulation. Activation percentages of >90Y0 were obtained for Si+ implantation annealed at 1400 C, while higher temperatures led to a decrease in both carrier concentration and electron mobility. No measurable redistribution of any of the implanted dopants was observed at 1450 C.

Date: November 20, 1998

Creator: Cao, X. A.; Fu, M.; Han, J.; Pearton, S. J.; Rieger, D. J.; Sekhar, J. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Implant activation and redistribution of dopants in GaN

GaN and related III-Nitride materials (IN, an) have recently been the focus of extensive research for photonic and electronic device applications. As this material system matures, ion implantation doping and isolation is expected to play an important role in advance device demonstrations. To this end, we report the demonstration of implanted p-type doping with Mg+P and Ca as well as n-type doping with Si in GaN. These implanted dopants require annealing 105 approximately1100 {degrees}C to achie… more

Date: July 1, 1996

Creator: Zolper, J. C.; Pearton, S. J.; Wilson, R. G. & Stall, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Gallium nitride junction field effect transistors for high-temperature operation

GaN is an attractive material for use in high-temperature or high-power electronic devices due to its high bandgap (3.39 eV), high breakdown field ({approximately}5 {times} 10{sup 6} V/cm), high saturation drift velocity (2.7 {times} 10{sup 7} cm/s), and chemical inertness. To this end, Metal Semiconductor FETs (MESFETs), High Electron Mobility Transistors (HEMTs), Heterostructure FETs (HFETs), and Metal Insulator Semiconductor FETs (MISFETs) have all been reported based on epitaxial AlN/GaN st… more

Date: June 1, 1996

Creator: Zolper, J. C.; Shul, R. J.; Baca, A. G.; Hietala, V. M.; Pearton, S. J.; Stall, R. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Redistribution of Implanted Dopants in GaN

Donor (S, Se and Te) and acceptor (Mg, Be and C) dopants have been implanted into GaN at doses of 3-5x1014 cm-2 and annealed at temperatures up to 1450 *C. No redistribution of any of the elements is detectable by Secondary Ion Mass Spectrometry, except for Be, which displays an apparent damage-assisted diffusion at 900 "C. At higher temperatures there is no further movement of the Be, suggesting that the point defect flux that assists motion at lower temperatures has been annealed. Effective d… more

Date: November 20, 1998

Creator: Fu, M.; Gao, X. A.; Han, J.; Pearton, S. J.; Rieger, D. J.; Scarvepalli, V. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High Voltage GaN Schottky Rectifiers

Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high bias… more

Date: October 25, 1999

Creator: Cao, X. A.; Cho, H.; Chu, S. N. G.; Chuo, C. C.; Chyi, J. I.; Dang, G. T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Role of C, O and H in III-V nitrides

The light ion impurities C, 0 and H have been implanted or diffused into GaN and related compounds and their effect on the electrical properties of these materials measured by Hall, C-V and SIMS as a function of annealing temperatures from 300--11OO{degree}C. While C in as-grown GaN appears to create an acceptor under MOMBE conditions, implanted C shows no measurable activity. Similarly, implanted 0 does not show any shallow donor activity after annealing at {le}700{degree}C, but can create hig… more

Date: December 1, 1995

Creator: Abernathy, C. R.; Pearton, S. J.; MacKenzie, J. D.; Lee, J. W.; Vartuli, C. B.; Wilson, R. G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Growth and Fabrication of GaN/AlGaN Heterojunction Bipolar Transistor

A GaN/AlGaN heterojunction bipolar transistor structure with Mg doping in the base and Si Doping in the emitter and collector regions was grown by Metal Organic Chemical Vapor Deposition in c-axis Al(2)O(3). Secondary Ion Mass Spectrometry measurements showed no increase in the O concentration (2-3x10(18) cm(-3)) in the AlGaN emitter and fairly low levels of C (~4-5x10(17) cm (-3)) throughout the structure. Due to the non-ohmic behavior of the base contact at room temperature, the current gain … more

Date: March 16, 1999

Creator: Abernathy, C. R.; Baca, A. G.; Cao, X. A.; Cho, H.; Dang, G. T.; Donovan, S. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

300 Degree C GaN/AlGaN Heterojunction Bipolar Transistor

A GaN/AIGaN heterojunction bipolar transistor has been fabricated using C12/Ar dry etching for mesa formation. As the hole concentration increases due to more efficient ionization of the Mg acceptors at elevated temperatures (> 250oC), the device shows improved gain. Future efforts which are briefly summarized. should focus on methods for reducing base resistance.

Date: October 14, 1998

Creator: Abernathy, C. R.; Baca, A. G.; Cho, H.; Chow, P. P.; Han, J.; Hichman, R. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department