Abstract
The effects of substrate temperature, RF power, and $NH_{3}/SiH_{4}$ gas flow ratio on the dielectric constant and optical bandgap of amorphous silicon nitride (a-SiNx:H) thin films prepared by PECVD method using RF glow discharge decomposition of $SiH_{4}$ and $NH_{3}$ gas mixtures have been studied. The dielectric constant and optical bandgap of a-SiNx:H thin films were greatly exchanged as by increasing substrate temperature, RF power, and $NH_{3}/SiH_{4}$ gas flow ratio. The dielectric constant of a-SiNx:H films was increased and optical bandgap of a-SiNx:H films was decreased as the substrate temperature was increased. When the substrate temperature, RF power, gas pressure, $NH_{3}/SiH_{4}$ gas flow ratio, and thickness were $250^{\circ}C$, 20 W, 500 mTorr, 10 and $1500\;{\AA}$, respectively, the dielectric constant, breakdown field and optical bandgap of a-SiNx:H film were 4.3, 1 MV/cm, and 2.9 eV, respectively.
$SiH_{4}$와 $NH_{3}$의 RF 글로우방전 분해에 의한 PECVD법으로 a-SiNx:H박막을 제조하고 기판온도, RF 전력, 그리고 $NH_{3}/SiH_{4}$ 유량비 등의 변화에 따른 a-SiNx:H 박막의 유전상수와 광학적 밴드갭 등을 조사하였다. a-SiNx:H막의 유전상수와 광학적 밴드갭은 기판온도, RF 전력 및 $NH_{3}/SiH_{4}$ 유량비 등의 증착변수에 따라 크게 변화하였다. 기판온도가 증가할수록 a-SiNx:H막의 유전상수는 증가하였으며 광학적 밴드갭은 감소하였다. 기판온도, RF 전력, 가스압력, $NH_{3}/SiH_{4}$ 유량비 및 두께를 각각 $250^{\circ}C$, 20 W, 500 mTorr, 10 및 $1500\;{\AA}$로 하였을 때 a-SiNx:H막의 유전상수, 절연파괴전장 및 광학적 밴드갭은 각각 4.3, 1 MV/cm 및 2.9 eV로 나타났다.