Semiconductor Switch Device Gate Electrode Configuration for Distortion Reduction
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Solution Overview
Problem
Third-generation cellular phone systems face issues with intermodulation distortion and harmonic distortion, which were not considered in second-generation systems, leading to reception errors, and there is a need to improve the distortion characteristic of semiconductor switch devices.
Innovation Solution
The semiconductor switch device incorporates a combination of depletion-type FET (D-type) and enhancement-type FET (E-type) elements on a single substrate with specific recess shapes and gate electrode configurations, such as rectangular and V-shaped gates, to enhance linearity of capacitance characteristics and reduce stray capacitance, thereby improving distortion performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional FET structure is used in switch circuits, then the device can be manufactured with standard processes, but the distortion characteristic (harmonic and intermodulation distortion) deteriorates due to non-linear capacitance characteristics
Solution Approach 1:
The patent applies local quality by creating different recess shapes (first recess with larger width, second recess with smaller width) at different locations within the same semiconductor element. This local differentiation modifies the electric field distribution specifically in the channel region, improving capacitance linearity and reducing distortion characteristics without changing the overall device structure or manufacturing process
2Reliability
If the gate electrode width is increased to improve capacitance linearity, then the distortion characteristic improves, but the channel resistance increases
Solution Approach 1:
The patent segments the gate electrode structure by creating a multi-level recess configuration with different widths at different depths. The first recess portion has a larger width to improve capacitance linearity, while the second recess portion has a smaller width to maintain low channel resistance. This segmentation allows independent optimization of both parameters that would otherwise be conflicting in a uniform structure
3Reliability
If a mixed configuration of rectangular and V-shaped gates is used, then the switch circuit performance improves, but the device complexity increases
Solution Approach 1:
The patent merges different gate electrode configurations (rectangular gates in switch circuit elements, V-shaped gates in connection circuit elements) within a single semiconductor device. This combination allows the switch circuit to benefit from rectangular gate characteristics while the connection circuit uses V-shaped gate characteristics, achieving overall performance improvement without requiring separate devices
Data Source
AI summary
A semiconductor switch device and a method of manufacturing the semiconductor switch device are provided. The semiconductor switch device includes semiconductor elements on a single semiconductor substrate. At least one of the semiconductor elements constitutes a switch circuit and at least one other of the semiconductor elements constitutes a logic (connection) circuit. Each semiconductor element includes a recess, a gate electrode in the recess, a drain electrode, and a source electrode. In one representative aspect, the gate electrode in the switch circuit can have a rectangular external shape in section, and the gate electrode in the connection circuit has a shape in section other than rectangular.