Schottky Diode Edge-Well Structure for Higher Breakdown Voltage
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Solution Overview
Problem
Schottky Barrier Diodes (SBDs) have a relatively low breakdown voltage and high reverse leak current due to strong electric fields, which can lead to premature breakdown and reduced performance in electronic circuits.
Innovation Solution
The semiconductor structure incorporates a P-type well region connected to the anode of the SBD, with a higher doping concentration contact region grounded, introducing a PN junction that reduces edge curvature of the Schottky junction, improving breakdown voltage and reducing leak current while maintaining high frequency and low voltage drop characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a Schottky junction is formed between metal structure and N-type semiconductor, then high switching frequency and low forward voltage drop are achieved, but breakdown voltage is reduced and reverse leak current is increased
Solution Approach 1:
A P-type well region is introduced as an intermediary layer between the metal structure and the N-type semiconductor. This P-type well region is in contact with the edge portion of the metal structure and separates it from the N-type semiconductor, thereby reducing the edge curvature effect and strengthening the electric field control at the Schottky junction edge, which improves breakdown voltage without sacrificing the high switching frequency and low forward voltage drop characteristics
Solution Approach 2:
The P-type well region is specifically positioned at the edge portion where the Schottky junction forms, creating a localized modification to the electric field distribution. This local quality change addresses the edge curvature problem specifically without affecting the overall Schottky junction performance in the middle portion
2Quantity of substance
If edge portion of metal structure contacts N-type semiconductor, then Schottky junction is formed, but strong electric field causes band-to-band tunneling current increasing reverse leak current
Solution Approach 1:
The P-type well region acts as a mediator between the metal edge portion and the N-type semiconductor, preventing direct contact that would create strong electric fields. This intermediary layer reduces the electric field intensity at the edge, thereby suppressing band-to-band tunneling current and reducing reverse leak current
3Strength
If strong electric field is concentrated at Schottky junction edge, then junction is formed, but breakdown occurs in advance reducing breakdown voltage
Solution Approach 1:
The P-type well region is strategically placed at the edge portion where electric field concentration occurs, creating a local modification to the electric field distribution. This local quality change redistributes the electric field, preventing excessive concentration at the edge and thereby improving breakdown voltage while maintaining junction strength
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 increases the breakdown voltage and reduces the leak current of the SBD, enhancing its performance by extending the depletion layer and preventing premature breakdown, while maintaining the high frequency and low voltage drop characteristics of the SBD.
Implementation Method 1
Under a condition that a positive voltage is applied to the N-type semiconductor 20 to deplete the N-type semiconductor 20, the Schottky junction (depletion layer) corresponding to each edge portion of the metal structure 10 has a certain curvature
Implementation Method 2
An SBD (Schottky Barrier Diode) has advantages of high switching frequency and low forward voltage drop, and is widely used in electronic circuits
Implementation Method 3
the Schottky junction (depletion layer) corresponding to each edge portion of the metal structure 10 has a certain curvature
Data Source
AI summary
Disclosed is a semiconductor structure and a manufacturing method. The semiconductor structure includes an N-type doped region in a substrate; a metal structure on a surface of the substrate and including a middle portion and an edge portion, wherein the middle portion is in contact with the N-type doped region so as to form an SBD; a first P-type well region which is located in the N-type doped region, in contact with the edge portion and separates the edge portion from the N-type doped region; a first P-type contact region located in the first P-type well region and separated from the edge portion. When the first P-type contact region is grounded, the first P-type well region receives an anode voltage of the SBD. Low voltage drop and high frequency characteristics of the SBD are maintained on a premise of improving the breakdown voltage reducing the leak current.