Abstract
We examined the dependence of the growth of undoped InP epilayer by chloride vapor phase epitaxy on the growth temperature and on the $PCl_3$molar fraction. The growth temperature was varied from $620^{\circ}C$ to $650^{\circ}C$ and the $PCl_3$molar franction from $2.5{\times}10^{-2}$ to $4.5{\times}10^{-2}$. The undoped InP epilayer with hillock free surface was obtained at the growth temperature of $640^{\circ}C$ and at the PCl$_3$molar fraction of $3.0{\times}10^{-2}$. The surface morphology was improved with a decrease of the PCl$_3$molar fraction. The carrier concentration measured by Hall and ECV was less than $1{\times}10^{14}cm^{-3}$. The resistivity of the undoped InP epilayer, measured by using four probe method, showed a high value of <$3.0{\times}10^6{\Omega}\textrm{cm}$.
$In/PCI_3/H_2$계 chloride VPE법을 이용하여 반절연(semi-insulating) Fe-doped InP 기 판위에 undoped InP 에피층(epilayer) 성장시 중요한 변수인 성장온도와 $PCl_3/H_2$몰비가 에피층 성장에 미치는 영향을 조사하였다. 성장온도를 $620^{\circ}C$에서 $650^{\circ}C$까지 변화시켰고, $PCl_3/H_2$ 몰비는 $2.5{\times}10^{-2}$에서 4.5$\times$10-2까지 변화시켰다. 성장온도가 $640^{\circ}C$이고 $PCl_3/H_2$ 몰비가 $3.0{\times}10^{-2}$에서 표면결함이 최소가 되었고, $PCl_3/H_2$ 몰비가 증가할수록 표면결함이 증가하는 경향을 나타내었다. photoluminescence(PL), Hall, electrochemical capacitance-voltage(ECV) 측정을 통해 모든 undoped InP 에피층의 상온 이동자 농도가 $1{\times}10^{14}cm^{-3}$ 보다 이하인 것을 확인하였고, four point probe method를 이용하여 측정한 비저 항(resistivity)은 성장온도가 $640^{\circ}C$, PCl3/H2 몰비가 $3.0{\times}10^{-2}$에서 $3.0{\times}10^6{\Omega}\textrm{cm}$으로 가장 높 은 값을 보였다.