Super-junction Semiconductor Device with Sandwich Epitaxial Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional super-junction semiconductor devices face challenges in maintaining a high breakdown voltage due to excessively strong electric fields at the middle region, leading to premature breakdown and a reduced process window.
Innovation Solution
A super-junction semiconductor device with an epitaxial layer having a sandwich structure, where the band gap of the lower layer is greater than that of the upper layer, preventing the middle region from premature breakdown by maintaining a higher critical electric field, thus expanding the process window for desirable breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electric field intensity at the middle region of the super-junction structure is increased to enlarge the process window, then the breakdown voltage control range is improved, but the semiconductor device may experience premature breakdown resulting in reduced breakdown voltage
Solution Approach 1:
The patent introduces a guard ring structure at the middle region of the super-junction device, creating a localized structural modification. This guard ring has different doping concentration and geometric dimensions compared to the main super-junction pillars, forming a local quality difference that specifically addresses the electric field distribution problem at the middle region without affecting the overall charge balance
Solution Approach 2:
The guard ring acts as an intermediary structure between the anode and cathode regions at the middle position. It mediates the electric field distribution by providing an intermediate doping region that modifies the field intensity, preventing direct breakdown between the main P and N regions while maintaining the desired process window
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 effectively expands the process window for a desirable breakdown voltage without damaging the super-junction structure under high-withstand conditions, ensuring high voltage resistance and preventing middle region breakdown.
Implementation Method 1
an epitaxial layer comprising a first semiconductor layer, and a second semiconductor layer disposed on the first semiconductor layer, wherein a band gap of the first semiconductor layer is greater than a band gap of the second semiconductor layer
Data Source
AI summary
A super-junction semiconductor device with an enlarged process window for a desirable breakdown voltage includes: a semiconductor substrate and an epitaxial layer deposited on the semiconductor substrate. The epitaxial layer includes a first semiconductor layer, and a second semiconductor layer disposed on the first semiconductor layer. A band gap of the first semiconductor layer is greater than a band gap of the second semiconductor layer. A super-junction structure is formed in the epitaxial layer, including at least one first epitaxial pillar of a first dopant type, and at least one second epitaxial pillar of a second dopant type. The first epitaxial pillar and the second epitaxial pillar are alternately arranged along a transverse direction. The epitaxial layer has a sandwich structure.