Ion-beam processing effects on the thermal conductivity of n-GaN/sapphire (0001)
Ion-beam processing effects on the thermal conductivity of n-GaN/sapphire (0001)
复制标题
DOI：
10.1063/1.1428798
复制
发表时间：
2002-01
影响因子：
3.2
通讯作者：
D. I. Florescu;F. Pollak;W. Lanford;F. Khan;I. Adesida;R. Molnar
中科院分区：
文献类型：
--
作者：
D. I. Florescu;F. Pollak;W. Lanford;F. Khan;I. Adesida;R. Molnar
利用扫描热显微镜测量了氢化物气相外延生长的两个系列n-GaN蓝宝石（0001）样品在300 K下等离子体诱导前后的高空间/深度分辨率（2 - 3 μ m）热导率（κ）。第一组样品厚度为50 ± 5 μ m，第二组样品厚度为25 ± 5 μ m。通过霍尔效应测量，载流子浓度分别为1.8 × 1016 cm − 3和1.5 × 1017 cm − 3。处理前的热导率与先前报道的具有可比载流子浓度和厚度的氢化物气相外延材料的热导率相似[D. I. Florescu等人，J. Appl.Phys.88，3295（2000）]。通过在恒定的Ar+气体流量和压力下对样品进行离子束处理持续固定的时间段（5分钟）来诱导损伤，其中直流偏置电压（Vdc）是唯一可变的处理参数（125 - 500 V）。在实验范围内，表面附近的热导率κ随Vdc的增大而线性减小。
We have measured high spatial/depth resolution (2–3 μm) thermal conductivity (κ) at 300 K before and after plasma-induced effects on two series of n-GaN sapphire (0001) samples fabricated by hydride vapor phase epitaxy using scanning thermal microscopy. The sample thicknesses were 50±5 μm for one set and 25±5 μm for the second. The carrier concentrations were ∼8×1016 cm−3 and ∼1.5×1017 cm−3, respectively, as determined by Hall effect measurements. The thermal conductivity before treatment was similar to that previously reported for hydride vapor phase epitaxy material with comparable carrier concentration and thickness [D. I. Florescu et al., J. Appl. Phys. 88, 3295 (2000)]. Damage was induced by ion-beam processing the samples under constant Ar+ gas flow and pressure for a fixed period of time (5 min), with the dc bias voltage (Vdc) being the only variable processing parameter (125–500 V). The thermal conductivity near the surface, κ, was found to exhibit a linear decrease with Vdc in the investigated ra...