Characterization of hydrogen etched 6H–SiC(0001) substrates and subsequently grown AlN films
Characterization of hydrogen etched 6H–SiC(0001) substrates and subsequently grown AlN films
复制标题
氢蚀刻 6H-SiC(0001) 衬底和随后生长的 AlN 薄膜的表征
DOI：
10.1116/1.1539080
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
R. Nemanich
中科院分区：
文献类型：
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作者：
J. Hartman;A. Roskowski;Z. Reitmeier;Tracy Kieran Mark;R. Davis;R. Nemanich
在1500-1640 °C、1atm、25%H_2/75%He混合气体中，对（ND-NA）=（5.1-7.5）× 10 ~（17）和2.5× 10 ~（18）的n型6 H-SiC（0001）晶片进行了腐蚀。 平衡热力学计算表明，原子氢的存在下是必要的，以实现SiC的蚀刻。原子力显微镜，光学显微镜，和低能量电子衍射的蚀刻表面揭示了一个刻面的表面形态与单位细胞和半单位细胞高的步骤和1×1重建。后一种样品在表面上也表现出大量的六边形凹坑。在1030 °C的超高真空（UHV）下退火蚀刻的样品15分钟导致（1）表面氧和外来烃的减少低于俄歇电子能谱的检测限，（2）（103 × 103）R30°重构表面和（3）Si与C的峰-峰高度比为1.2。 相比之下，使用化学气相清洁（CVC）工艺，该工艺包括在1030 ℃下暴露于3000朗缪尔（L）的硅烷。
Wafers of n-type, 6H–SiC(0001) with (ND–NA)=(5.1–7.5)×1017 and 2.5×1018 were etched in a flowing 25%H2/75%He mixture within the range of 1500–1640 °C at 1 atm. Equilibrium thermodynamic calculations indicated that the presence of atomic hydrogen is necessary to achieve etching of SiC. Atomic force microscopy, optical microscopy, and low energy electron diffraction of the etched surface revealed a faceted surface morphology with unit cell and half unit cell high steps and a 1×1 reconstruction. The latter sample also exhibited a much larger number of hexagonal pits on the surface. Annealing the etched samples under ultrahigh vacuum (UHV) at 1030 °C for 15 min resulted in (1) a reduction of the surface oxygen and adventitious hydrocarbons below the detection limit of Auger electron spectroscopy, (2) a (√3×√3)R30° reconstructed surface and (3) a Si-to-C peak-to-peak height ratio of 1.2. By contrast, using a chemical vapor cleaning (CVC) process consisting of an exposure to 3000 Langmuir (L) of silane at 1030 ...