HEMT Stepped Field Plate Layout for Higher Breakdown Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional high electron mobility transistors (HEMTs) have complex manufacturing processes and high costs due to the need for multiple photo-masks and complex field plate structures, which increase the complexity and expense of producing these high-frequency and high-power semiconductor devices.
Innovation Solution
A patterned dielectric layer with a higher dielectric constant is used between the gate and drain electrodes to create a stepped field plate effect, reducing the number of photo-masks required and simplifying the manufacturing process by forming multiple field plates with the same conductive material layer, while also enhancing the breakdown voltage through electric field redistribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional field plate structures are used to regulate electric field distribution, then breakdown voltage is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent introduces a vertical dimension to the field plate structure by creating a stepped configuration where the field plate extends at different heights above the semiconductor substrate. This dimensional change allows multiple field regulation zones to be formed using a single conductive layer, simplifying the manufacturing process while maintaining effective electric field control for high breakdown voltage
Solution Approach 2:
The field plate is segmented into multiple stepped portions at different heights, where each step creates a specific electric field regulation zone. This segmentation allows the single field plate structure to perform multiple field control functions that would traditionally require multiple separate field plates or additional conductive layers
2Manufacturing precision
If multiple photo-masks are used to form field plates and electrodes, then manufacturing precision is improved, but manufacturing cost and process time increase
Solution Approach 1:
The patent merges the formation of field plates and electrodes into a single patterning step using one photo-mask. The conductive layer is patterned to simultaneously define both the field plate regions and electrode regions, eliminating the need for separate photo-masks and reducing manufacturing steps while maintaining alignment precision
Solution Approach 2:
The single photo-mask design serves multiple functions by defining both field plate patterns and electrode patterns in one exposure step. This universal patterning approach simplifies the manufacturing process and reduces the total number of lithography steps required
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 solution reduces manufacturing costs and improves the breakdown voltage of HEMTs by redistributing the electric field and creating a stepped field plate effect without the need for additional conductive material layers, thereby enhancing the device's performance and efficiency.
Implementation Method 1
The dielectric constant of the patterned dielectric layer is higher than both the dielectric constant of the first dielectric layer and the dielectric constant of the second dielectric layer
Data Source
AI summary
A high electron mobility transistor includes a semiconductor channel layer and a semiconductor barrier layer disposed on a substrate. A source electrode, a gate electrode and a drain electrode are disposed on the semiconductor channel layer. A patterned dielectric layer is disposed on the semiconductor barrier layer, and between the gate electrode and the drain electrode. A first field plate is extended continuously from a side of the patterned dielectric layer to the top surface thereof, and has a step in height. A first dielectric layer is disposed between the semiconductor barrier layer and the patterned dielectric layer. A second dielectric layer covers the patterned dielectric layer. The dielectric constant of the patterned dielectric layer is higher than that of the first dielectric layer and the second dielectric layer.