Sulfuric Acid Treatment of Sapphire Substrates for Growth of High-Quality Epilayers |
Ji-Won Park, Young-Soo No1, Yeon-Sik Jung2, Seok-Jin Yoon2, Tae-Whan Kim3, Won-Kook Park |
Thin Film Materials Research Center, Korea Institute of Science and Technology 1Thin Film Materials Research Center, Korea Institute of Science and Technology, Division of Electrical and Computer Engineering, Hanyang Universit 2Thin Film Materials Research Center, Korea Institute of Science and Technolog 3Division of Electrical and Computer Engineering, Hanyang Universit |
|
|
|
ABSTRACT |
The chemical etching of sapphire substrates was peformed to produce smooth surfaces on an atomic scale. The sapphire sur-face etched by using a $H_2$S $O_4$ solution showed a pit-free morphology and was yen smooth as much as $sigma$$_{rms}$=0.13 nm, that etched by using a mixture of $H_2$S $O_4$ and $H_3$P $O_4$ contained large pits with $sigma$$_{rms}$=0.34 nm. The $sigma$$_{rms}$’s and the number of the pits increased with increasing etching temperature. The sapphire etched by using $H_2$S $O_4$ at 32$0^{circ}C$ had the best surface. These results provide important information on the effects of etching treatment on the structural properties of sapphire for the growth of high-quality epilayers.ayers. |
Key words:
Chemical etching of sapphire, Pit-free morphology, $H_2$$SO_4$ |
|
|
|