Activation of Mg-doped P-GaN by using two-step annealing

Electrical characteristics of Mg-doped p-GaN treated with the electrochemical potentiostatic activation method

“…For an efficient activation of p-GaN, a number of studies were attempted by employing the post-thermal annealing process [3][4][5], minority carrier injection [6,7], laser irradiation [8][9][10], and etc. Very recently, the electrochemical potentiostatic activation (EPA) method [11] was proposed to improve the electrical characteristics of Mg-doped p-GaN.…”

Effect of using two-step thermal annealing with different ambient gas on Mg activation and crystalline quality in GaN

“…On the other hand, the annealing temperature in O 2 and air was applied at 700°C and 500°C, respectively. These temperatures are chosen based on the optimization works by Hwang and Yang [5] and Lin [7]. Details of the annealed sample are listed in Table 1.…”

“…Advanced technique in the thermal annealing process has been reported by proposing two-step thermal annealing for activating the Mg doping in GaN. Most of the works however gave focus on changing the temperature in two different steps of the annealing using only a single gas [5,6]. This is purposely to break the Mg-H bonds in a more effective way.…”

“…Nonetheless, such annealing treatment may not completely break the Mg-H bonds and improve quality structure of sample at the same time. For example, Hwang and Yang [5] had proposed two-step annealing using different temperatures in O 2 ambience. They achieved high hole concentration about 6 Â 10 17 cm À3 for the sample annealed at 750°C in O 2 ambience but the effect of the annealing on the crystal structure of the sample is not reported.…”

Electrochemical potentiostatic activation for improvement of internal quantum efficiency of 385-nm ultraviolet light-emitting diodes

“…In 1992, Nakamura et al suggested a thermal annealing method above 700 • C [10], which is currently adopted by most chip makers to activate p-GaN layers. Since then, several modified methods have been suggested, such as KrF excimer-laser activation [11][12][13], multiple-step annealing [14], thermal annealing in an oxygen gas mixture [15], utilization of hydrogen-storage metal electrodes [16], and annealing with minority carrier injection [17,18]. Little achievement in hole concentration has been achieved by these methods, but these have basically not been suitable for mass production.…”