MANUFACTURE OF HEMT WHEREIN DOPING PROPERTY OF ALGAAS LAYER IS IMPROVED

    公开(公告)号:JPH02298040A

    公开(公告)日:1990-12-10

    申请号:JP6952190

    申请日:1990-03-19

    Abstract: PURPOSE: To improve the doping characteristic of an HEMT by lowering the concentration of an n-type impurity due to DX centers by epitaxially growing a III- or IV-element compound semiconductor layer, in which compound semiconductors having direct and indirect forbidden bands are mixed together on a semiconductor substrate having (111B) plane orientation. CONSTITUTION: A first layer 1 composed of such a semiconductor that is not doped, and having a narrow forbidden band width is grown by using a substrate 9 having a (111B) plane orientation. Then a first semiconductor layer 1 is grown for forming a two-dimensional electron gas 4 and a second three- or four- dimensional semiconductor layer 2, which has a forbidden band width wider than that of the layer 1 and doped with an n-type impurity is grown so as to form a heterogeneous structure 3. In addition, an n-type semiconductor layer 5 is grown to improve a resistive contact. Finally, an HEMT is manufactured by forming a source electrode 6 and a drain electrode 7 on the layer 5 and a gate electrode 8, for adjusting the concentration of the electron gas 4. Therefore, the doping characteristic of the HEMT can be improved by lowering the concentration of the n-type impurity at the DX centers (deep level).

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