High resistive undoped Al/sub 0.48/In/sub 0.52/As layers grown by MOCVD

It is shown that the resistivity and the conduction type of undoped MOCVD Al/sub 0.48/In/sub 0.52/As layers depend strongly on the growth temperature (450/spl deg/C-650/spl deg/C). The conduction type changes from n-type, semi-insulating and p-type with the decrease of the growth temperature. High resistivity over 2/spl times/10/sup 8/ /spl Omega/-cm is successfully obtained from undoped Al/sub 0.48/In/sub 0.52/As layers grown at 500/spl deg/C. With help of SIMS and ICTS, it is found that the resistivity is substantially determined by the incorporation of carbon whose incorporation rate depends strongly on the growth temperature. The incorporated carbon compensates the native deep donors. The good selective growth of undoped Al/sub 0.48/In/sub 0.52/As layers is also achieved at even low growth temperature of 500/spl deg/C. >