Plasma damage in p-GaN

Vertical-Injection GaN-Based Light-Emitting Diodes Fabricated With Schottky-Contact Current Blocking Layer

“…Note that at first, there were not any discernible changes to the Ga, N, and Pd before and after the plasma treatment. Indeed, this result is different from previous findings [13] that the conventional Ar plasma treatment induces the preferential loss of N atoms or the incorporation of O atoms, thereby compensating the acceptors. On the other hand, strikingly, the intensity of Mg atoms was reduced significantly upon Ar plasma exposure.…”

“…For example, the root-mean-square surface roughness was 4.2, 4.4, 4.9, and 3.3 Å for the reference and samples A, B, and C, respectively. This result is in contrast with the previous findings [13] that the Ar plasma treatment to GaN induced a significant increase in the surface roughness, in which the preferential loss of nitrogen, namely the generation of nitrogen vacancies acting as donors, causes the surface degradation. This is due to our mild plasma treatment condition in which the Ar plasma was generated under relatively low rf power of 40-150 W, the dc self-bias was nearly zero, and the process was performed quickly at room temperature.…”

Enhancement of light output powers of GaN-based light emitting diodes with textured indium tin oxide transparent layer by using corrosive liquid

“…Various surface roughening schemes have been presented for GaN-based LEDs [9][10][11]. However, most of these methods have involved complicated and timeconsuming inductively coupled plasma (ICP) technology during roughening the indium tin oxide (ITO) layer, which will probably make etching damagement to the ITO layer and even the p-GaN layer [12]. Moreover, it is difficult to etch the ITO layer by using ICP dry etching technology.…”

Effect of N2 Plasma Treatments on Dry Etch Damage in n- and p-type GaN

“…(1)(2)(3)(4)(5) Initial research on dry etching of GaN focused on achievement of high etch rates and smooth surface morphologies. (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) However this effect is not desirable in situations in which a gate recess is formed by selectively removing GaN from AlGaN in heterostructure field effect transistors or when the p-base region is exposed in npn heterojunction bipolar transistors. The general effect of plasma damage in GaN is to create a degenerately-doped n + surface region, which leaves n-ohmic contact resistance.…”

“…The general effect of plasma damage in GaN is to create a degenerately-doped n + surface region, which leaves n-ohmic contact resistance. (3,6,9,11,14) The damaged region appears to be rapidly removed in hot KOH or acid solutions, but the underlying undamaged GaN does not etch at a measurable rate. (1,4) Previous attempts at removing dry etch damage in GaN have focussed on annealing or wet etch clean-up steps.…”