Method of manufacturing a hemt device with reduced gate leakage current, and hemt device
AssigneeStimicroelectronics S.R.L.
InventorsFerdinando Iucolano, Paolo Badala'
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Abstract
An HEMT device of a normally-on type, comprising a heterostructure; a dielectric layer extending over the heterostructure; and a gate electrode extending right through the dielectric layer. The gate electrode is a stack, which includes: a protection layer, which is made of a metal nitride with stuffed grain boundaries and extends over the heterostructure, and a first metal layer, which extends over the protection layer and is completely separated from the heterostructure by said protection layer.
Claims21
A method, comprising:
- manufacturing a high electron mobility transistor (HEMT) device of a normally-on type, the manufacturing including:
- forming a gate electrode on a semiconductor body that includes a semiconductor heterostructure;
- and
- forming a dielectric layer on the heterostructure, wherein forming the gate electrode comprises:
- forming a trench through the dielectric layer until a surface region of the heterostructure is reached;
- forming a sacrificial layer in the trench and on the dielectric layer;
- selectively removing the sacrificial layer from the trench, the selectively removing completely exposing said surface region of the heterostructure;
- forming in the trench and on the sacrificial layer, by reactive evaporation, a protection layer made of a metal nitride;
- forming a first metal layer on the protection layer;
- and
- carrying out a lift-off step, simultaneously removing said sacrificial layer and portions of the protection layer and of the first metal layer on the sacrificial layer.
A high electron mobility transistor (HEMT) device of a normally-on type, comprising:
- a semiconductor heterostructure;
- a dielectric layer extending over the heterostructure;
- and
- a gate electrode extending through the dielectric layer, wherein the gate electrode is a stack, which includes:
- a protection layer, made of a metal nitride with stuffed grain boundaries, extending over the heterostructure;
- and
- a first metal layer extending over the protection layer and completely separated from the heterostructure by said protection layer.
A method, comprising:
- manufacturing a high electron mobility transistor (HEMT) device of a normally-on type, the manufacturing including:
- forming a semiconductor heterostructure on a semiconductor substrate, forming the heterostructure includes forming a semiconductor channel layer and forming a semiconductor barrier layer on the channel layer, the channel layer and barrier layer being made of respective compounds that include elements of Groups III and V;
- forming a dielectric layer on the heterostructure;
- forming source and drain electrodes completely through the dielectric later and the barrier layer and contacting the channel layer;
- forming a gate electrode extending through the dielectric layer and contacting the barrier layer, wherein forming the gate electrode comprises:
- forming a protection layer made of a metal nitride;
- and
- forming a first metal layer on the protection layer.
Dependencies are inferred from the claim text.