| 摘要 |
PURPOSE:To control the quantity of fine impurities to be added into a growing layer accurately, by employing a semiconductor crystal, which has the same composition as that of a source crsytal which is to become a growing material and on the surface of which a thin film comprising an impurity element to be doped is deposited, as an impurity material used for liquid phase epitaxial growing. CONSTITUTION:It is very difficult to measure very small amount of metal Te when a Te doping type Ga0.5Al0.5As layer, which has impurity concentration such as carrier concentration of 5X20<17>/cm<3> at a growing temperature of 800 deg.C, is grown on a substrate such as GaAs. Therefore the following method is employed. The growing material is constituted by Ga, Al, GaAs, and Te. However, since the quantity of inclusiion of Te is as extremely small as 0.035mg, a GaAlAs crystal, on which a thin Te film is deposited to about 1mum, is employed instead of using metal Te. At this time the impurities to be added are not limited to Te. In this method, extremely fine quantity of impurities can be added. |
