Abstract: A high electron mobility transitor has a channel layer overlain by an electron supply layer held in contact with a gate electrode, and source/drain electrodes form ohmic contact together with cap layers, and resistive etching stopper are inserted between the cap layers and the electron supply layers for preventing the electron supply layer from over-etching, wherein extremely thin delta-doped layers are formed between the etching stopper layers and the electron supply layer so that the resistance between the electron supply layer and the source/drain electrodes are reduced.

Abstract: A high electron mobility transistor has a channel layer overlain by an electron supply layer held in contact with a gate electrode, and source/drain electrodes form ohmic contact together with cap layers, and resistive etching stopper are inserted between the cap layers and the electron supply layers for preventing the electron supply layer from over-etching, wherein extremely thin delta-doped layers are formed between the etching stopper layers and the electron supply layer so that the resistance between the electron supply layer and the source/drain electrodes are reduced.

Abstract: A recess is made in the semiconductor substrate. A gate electrode has a sectional shape of "T" to have a head overhanging portion and is made in the recess. The gate electrode having a head overhanging portion. A capacitance film is formed under the head overhanging portion of the gate electrode. An ohmic electrode is formed on the semiconductor substrate and at both sides of the gate electrode. In the device, the capacitance film is made of a photosensitive organic film having a smaller permittivity than that of silicon oxide films. This semiconductor device has a small gate parasitic capacitance and the variation in the capacitance can be reduced.

Abstract: A method of promoting evaporation of excess indium from a surface of an indium containing compound semiconductor single crystal layer during a discontinuation of a molecular beam epitaxial growth. Substantial supply of all elements for the indium containing compound semiconductor single crystal layer are stopped at least until a substrate temperature rises to a predetermined temperature of not less than an indium re-evaporation initiation temperature.

Abstract: A semiconductor device includes a base case 12, a first conductive pattern 6 selectively formed on the base case 12 a semiconductor element 1 mounted on the first pattern 6, a second conductive pattern 7 selectively formed on the base case 12 and connected to a first electrode 2 of the semiconductor element 1, the second conductive pattern 7 being separated from the first conductive pattern 6 to form a first parasitic capacitance therebetween, and a third conductive pattern 8 selectively formed on the base case 12 and connected to a second electrode 3 of the semiconductor element 1, the third conductive pattern 8 being separated from the first conductive pattern 6 to form a second parasitic capacitance therebetween, the first parasitic capacitance being larger than the second parasitic capacitance.