Temperature-Dependent Studies of Si-Implanted Al0.33Ga0.67N with Different Annealing Temperatures and Times

Abstract

Electrical activation studies were carried out on Si-implanted Al 0.33 Ga 0.67 N as a function of ion dose, annealing temperature, and annealing time. The samples were implanted at room temperature with Si ions at 200 keV in doses ranging from 1 9 10 14 cm À2 to 1 9 10 15 cm À2 , and subsequently proximitycap annealed from 1150°C to 1350°C for 20 min to 60 min in a nitrogen environment. One hundred percent electrical activation efficiency was obtained for Al 0.33 Ga 0.67 N samples implanted with a dose of 1 9 10 15 cm À2 after annealing at either 1200°C for 40 min or at 1300°C for 20 min. The samples implanted with doses of 1 9 10 14 cm À2 and 5 9 10 14 cm À2 exhibited significant activations of 74% and 90% after annealing for 20 min at 1300°C and 1350°C, respectively. The mobility increased as the annealing temperature increased from 1150°C to 1350°C, showing peak mobilities of 80 cm 2 /V s, 64 cm 2 /V s, and 61 cm 2 /V s for doses of 1 9 10 14 cm À2 , 5 9 10 14 cm À2 , and 1 9 10 15 cm À2 , respectively. Temperature-dependent Hall-effect measurements showed that most of the implanted layers were degenerately doped. Cathodoluminescence measurements for all samples exhibited a sharp neutral donor-bound exciton peak at 4.08 eV, indicating excellent recovery of damage caused by ion implantation.

Electrical Activation Studies of Silicon-Implanted Al x Ga1−x N with Aluminum Mole Fraction of 11% to 51%

“…Recently, our group achieved nearly perfect electrical activation efficiencies from Si-implanted Al x Ga 1Àx N with an Al mole fraction more than 30%. 11,12 In the present paper, electrical activation studies of Si-implanted Al x Ga 1Àx N at 200 keV with doses ranging from 1 9 10 14 cm À2 to 1 9 10 15 cm À2 are reported as a function of ion dose and annealing temperature for Al mole fractions from 11% to 51%.…”

Elevated-Temperature Annealing Effects on AlGaN/GaN Heterostructures

“…Silicon ion implantation is one of the viable methods for increasing the dopant concentrations in GaN and AlGaN semiconductors. [1][2][3][4][5][6][7] However, activation of implanted dopants requires high-temperature treatment, higher than the growth temperatures for dopant activation. MBE-grown GaN on sapphire with Si implantation at dose of 5 9 10 15 cm À2 showed over 100% increase in mobility after annealed at temperatures between 1050°C and 1350°C.…”

“…4 Silicon-implanted AlGaN demonstrated excellent activation at annealing temperatures as high as 1350°C. [5][6][7] On the negative side, MOCVDand MBE-grown AlGaN on sapphire samples were found to degrade in structure when annealed in air at 1100°C or at 1200°C in nitrogen. 8 AlGaN with high aluminum mole fraction of 0.72 was found to decompose upon annealing at 1150°C in the presence of small amounts of oxygen.…”