ABSTRACT
The vertical Bridgman method was employed for growing the /?-type ZnTe using 6N P or As. In order to decrease the melting point, Te-rich growth condition was adopted with 5% deviation from stoichiometry. Typical weights of 6N Zn and Te were 19 g and 45 g, respectively. To get the p -type P-or As-doped crystals, the small amount of the dopant was added into the sources. The atomic ratio of the dopant to Zn was within 6.7x10"4. These materials were cleaned and put into a quartz ampoule with the inner diameter of 16 mm. First, the ampoule was evacuated to a pressure of 10"6 Torr by the diffusion pumping system. Next, He gas was introduced into the ampoule and then excluded again. These procedures were repeated several times. Finally, the ampoule was sealed off in the vacuum level of 5x1 O'7 Torr. Furthermore, this ampoule was inserted into the other quartz ampoule and sealed off in almost same procedure in order to protect it from unexpected explosion during the growth. The furnace temperature was well controlled within ±1 °C deviation, and the maximum temperature was set to 1200 °C. The ZnTe crystal growth was started with a downward rate of 25 mm/day. After the growth, about fourteen pieces of the (001) ZnTe substrates with the dimensions of 8x8x1 mm3 were obtainable from the ingot.
