| 摘要 |
PURPOSE:To obtain an epitaxial crystal of high quality, by carrying out growth under different pressure depending on the crystal quality required in each growth layer, using a hydrogenated product of group V element and organometallic compound of group III element. CONSTITUTION:GaAs substrate 114 is installed in a prescribed position and growth of andope GaAs layer is applied. At the time, pressure in a reaction tube 111 is set to about 500 torr by carrying out the exhaust in the reaction tube 111 through a route A. In this process, growth rate is relatively quick and about 0.05mu/min and GAs layer of high purity can be grown, since an inner pressure of the reaction tube 111 is close to ordinary pressure. Then after passing for about 20min, the three way valve 12 is operated and exhaust route is changed to a route B. By this operation, an inner pressure of the reactive tube is reduced to about 50 torr and the growth rate is rapidly reduced to about 0.01mu/min. Then when the pressure attains constant state, Al(CH3)3 and SiH4 are fed into the reactive tube and growth of n type AlGaAs layer is carried out. After the prescribed time is passed, the feed of Al(CH3)3 is stopped and n type GaAs layer is grown for the prescribed time to complete the growth.
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