National Science Council

Lih-Wen Laih

Wen-Chau Liu

The present invention provides a structure of a metal-insulator-semiconductor (MIS)-like multiple-negative-differential-resistance (MNDR) device and the fabrication method thereof. The device of the present invention has the characteristics of dual-route and MNDR at low temperatures. These characteristics result from the successive barrier-lowering and potential-redistribution effect when conducting carriers fall into a quantum well. MNDR devices have excellent potential in multiple-value logic circuitry applications and are capable of reducing circuitry complexity.

Structure of metal-insulator-semiconductor-like multiple-negative-differential-resistance device and fabrication method thereof

The present invention provides a GaInP/GaInAs/GaAs modulation-compositioned channel field-effect transistor which comprises: a substrate of semi-insulated GaAs material; a first layer of non-doped GaAs material, formed on the substrate; a second layer of n-doped GaInAs material, formed on the first layer; a third layer of non-doped GaInP material, formed on the second layer; a fourth layer of n-doped GaAs material, formed on the third layer; an Au layer, formed on the third layer; and an Au/Ge/Ni alloy layer, formed on the fourth layer. An accumulation effect is performed because there is a V-shaped energy band existing in the modulation-compositioned channel. Therefore, the transistor of the present invention is characterized by a large current density, a large gate voltage swing with high transconductance, and a high gate breakdown voltage. The present invention has a good potentiality for high-speed, high-power, and large input signal circuit applications.

GaInP/GaInAs/GaAs modulation-compositioned channel field-effect

Structure of metal-insulator-semiconductor-like

A pseudomorphic step-doped-channel field-effect transistor is provided, which has advantages of large transconductance, high electron mobility, high gate voltage swing and high current density, and can increase the pinch-off voltage tolerance. Thus the pseudomorphic step-doped-channel field-effect transistor is suitable for high-speed, high-power, and large-input signal circuitry systems. The pseudomorphic step-doped-channel field-effect transistor comprises: a semi-insulating GaAs substrate; an undoped GaAs layer formed on the GaAs substrate to serve as a buffer layer; an n-doping InGaAs layer formed on the undoped GaAs layer to serve as a channel layer; an undoped AlGaAs layer formed on the n-doping InGaAs layer to serve as a Schottky contact layer; an n-doping GaAs layer formed on the undoped AlGaAs layer; and metal layers formed on the undoped AlGaAs layer and the n-doping GaAs layer to respectively serve as a gate, a drain and a source of the pseudomorphic step-doped-channel field-effect transistor.

Growing community of inventors

Tainan, Taiwan

Lih-Wen Laih