| 摘要 |
PURPOSE:To prevent the carrier mobility of a hetero-structure element from decreasing by specifying the distribution of x value of AlxGa1-xAs (0<x<1) near a hetero-boundary between AlxGa1-xAs and GaAs in an inverted structure HEMT, thereby preventing a transition layer of large Al molar ratio of the hetero-boundary from generating. CONSTITUTION:The x value of AlxGa1-xAs in a hetero-structure element having the first layer 11 of the AlxGa1-xAs (0<x<1), the second layer 12 of GaAs laminated thereon and a hetero boundary between the AlxGa1-xAs and the GaAs is increased between several atoms layers from the GaAs side toward the depthwise direction, and a distribution to become constant is then provided. For example, when the thicknesswise direction (d) is from the layer 11 toward the layer 12, the molar ratio (x) of the aluminum is controlled as shown. That is, a growth that the molar ratio of the aluminum is reduced before arriving at the prescribed hetero boundary d1 is performed, and the distribution of the x value is provided in the thickness of approx. 50Angstrom . Thus, the grown layer (AlxGa1-xAs) of the flat aluminum distribution is obtained to improve the carrier mobility of 2-dimensional electron gas layer generated at the GaAs layer side of the boundary to the AlxGa1-xAs. |
