Isolated gate field effect transistor and manufacture method thereof

Abstract

The invention discloses an isolated gate field effect transistor and the manufacture method thereof. Through the method of introducing metal when a dielectric layer is grown on a nitride transistor structure, the chemical properties of the dielectric layer are changed, and the effects of controlling etching speed and depth can be played. A groove structure is formed in a grid region in a partially thinned manner, and part of dielectric layer is reserved at the grid. A metal grid is arranged on the dielectric layer in the groove region of the grid, so as to form metal / dielectric layer / semi-conductor contact, and meanwhile, the groove is used for forming a field plate structure. Since the surface of a semi-conductor is protected by the dielectric layer during the entire technological process, damages to the surface of nitride, stress releasing and staining on the surface of the nitride can be greatly reduced, and the current collapsing effect of a device can be reduced greatly. Due to the MISFET (Metal Insulation Semiconductor Field Effect Transistor) or MOSFET (Metal-Oxide -Semiconductor Field Effect Transistor) structure is formed by the high-quality dielectric layer, current leakage of the grid can be reduced greatly.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and in particular relates to an insulated gate field effect transistor and a method for manufacturing the insulated gate field effect transistor. Background technique [0002] Group III nitride semiconductors have the characteristics of wide band gap, high dielectric breakdown electric field and high electron saturation drift velocity, and are suitable for making high-temperature, high-speed switching and high-power electronic devices. In GaN-based field-effect transistors, a large amount of charge is generated in the channel layer by piezoelectric polarization and spontaneous polarization. Since the source of the two-dimensional electron gas is the ionization of the donor surface state on the nitride surface, the current density of the nitride transistor is extremely sensitive to the surface state, which is likely to cause the current collapse effect. In addition, during the epitaxial ...

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Problems solved by technology

However, due to the repeatability of the etching process, the thickness of the remaining dielectric layer cannot be precisely controlled, resulting in a shift in the threshold voltage

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