Two-Level Field Plate Semiconductor Device for Breakdown Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LDMOS devices have insufficient depletion of the drift region due to a single-level field plate, limiting their breakdown voltage and electric field optimization at the gate polycrystalline boundary.
Innovation Solution
A method of manufacturing a semiconductor device involving the formation of a first field plate self-aligned with a gate polycrystalline and a second field plate on a second field oxide, enhancing the depletion of the drift region and improving the electric field at the gate boundary through a two-level field plate configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-level field plate is formed in the drift region, then the structure is simple and manufacturing is easier, but the depletion of the drift region is insufficient and breakdown voltage is limited
Solution Approach 1:
The field plate structure is segmented into two levels: a first field plate formed at a first potential and a second field plate formed at a second potential. This segmentation allows independent optimization of electric field control at different regions, enhancing drift region depletion and increasing breakdown voltage while maintaining manufacturing feasibility through sequential formation processes
2Device complexity
If a single-level field plate is used, then the manufacturing process is simpler, but the electric field optimization at the gate polycrystalline boundary is limited
Solution Approach 1:
Different field plates are applied to different regions with different electrical characteristics. The first field plate optimizes the electric field at the gate polycrystalline boundary region, while the second field plate enhances depletion in the drift region. This local quality approach allows precise electric field control in each critical region, improving manufacturing precision for high-voltage device characteristics
3Device complexity
If only one field plate level is provided, then the process is simpler, but the depletion of the drift region remains insufficient
Solution Approach 1:
The field plate structure is extended from a single-level (one-dimensional) configuration to a two-level (multi-dimensional) configuration. The first field plate is formed at a first height level and the second field plate is formed at a second height level, creating a multi-dimensional electric field control structure that enhances drift region depletion effectiveness without excessive process complexity
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 two-level field plate configuration increases the breakdown voltage of the semiconductor device by improving the depletion of the drift region and optimizing the electric field, addressing the limitations of conventional technologies.
Implementation Method 1
forming a drift region in the semiconductor substrate by ion implantation using a drift region masking layer as a mask
Data Source
AI summary
A semiconductor device, and a manufacturing method thereof. The method includes: providing a semiconductor substrate provided with a body region, a gate dielectric layer, and a field oxide layer, formed on the semiconductor substrate; forming a gate polycrystalline, the gate polycrystalline covering the gate dielectric layer and the field oxide layer and exposing at least one portion of the field oxide layer; forming a drift region in the semiconductor substrate by ion implantation using a drift region masking layer as a mask, removing the exposed portion of the field oxide layer by further using the drift region masking layer as the mask to form a first field oxide self-aligned with the gate polycrystalline; forming a source region in the body region, and forming a drain region in the drift region; forming a second field oxide on the semiconductor substrate; and forming a second field plate on the second field oxide.