Nitride Semiconductor Device Segmented Source Electrode Hydrogen Annealing
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Solution Overview
Problem
Current semiconductor devices using nitride semiconductors face limitations in improving characteristics such as threshold potential, breakdown voltage, and switching characteristics, particularly in normally-off operations.
Innovation Solution
A manufacturing method involving the formation of a first electrode with a gap above a gate electrode and subsequent hydrogen annealing, which enhances the semiconductor device's characteristics by mitigating stress, reducing capacitance, and improving the threshold potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a continuous electrically-conductive film is formed above the gate electrode to create a field plate, then the breakdown voltage is improved, but the capacitance between gate and source/drain regions increases and manufacturing complexity increases
Solution Approach 1:
The electrically-conductive film is divided into separate sections with gaps between them, creating a segmented field plate structure. This segmentation reduces the continuous coverage area, thereby reducing capacitance between gate and source/drain regions while still maintaining breakdown voltage improvement in critical areas. The manufacturing process is simplified compared to forming notched sections, as it uses standard photolithography patterning to create the segmented structure.
2Reliability
If hydrogen annealing is performed after forming the electrically-conductive film, then the threshold potential is improved and switching characteristics are enhanced, but the process time and manufacturing complexity increase
Solution Approach 1:
Hydrogen annealing is performed at a predetermined stage during the manufacturing process, before final device assembly and testing. This preliminary action allows the threshold potential to be optimized early in the process, and subsequent manufacturing steps can proceed without additional annealing operations, thereby reducing total process time while maintaining the reliability benefits.
3Loss of energy
If the electrically-conductive film is etched into a shape with openings, then the capacitance between gate and source/drain regions is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The electrically-conductive film is designed with openings only in specific locations where capacitance reduction is most beneficial, while maintaining continuous coverage in areas critical for breakdown voltage. This local quality approach allows selective etching with relaxed precision requirements compared to complete pattern removal, as the openings are concentrated in non-critical areas.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively raises the threshold potential, improves breakdown voltage, and enhances switching characteristics by efficiently supplying hydrogen to the channel region and reducing the area of contact between the gate and source electrodes.
Implementation Method 1
after the etching, the substrate is subjected to heat treatment in a hydrogen atmosphere
Implementation Method 2
efficiently supplying hydrogen to the channel region
Data Source
AI summary
The present invention makes it possible to improve the characteristic of a semiconductor device using a nitride semiconductor. An electrically-conductive film is formed above a gate electrode above a substrate with an interlayer insulation film interposed and a source electrode coupled to a barrier layer on one side of the gate electrode and a drain electrode coupled to the barrier layer on the other side of the gate electrode are formed by etching the electrically-conductive film. On this occasion, the source electrode is etched so as to have a shape extending beyond above the gate electrode to the side of the drain electrode and having a gap (opening) above the gate electrode. Successively, hydrogen annealing is applied to the substrate. In this way, by forming the gap at a source field plate section of the source electrode, it is possible to efficiently supply hydrogen in the region where a channel is formed in the hydrogen annealing process.