Schottky Diode Well Structure for Leakage and Breakdown Control
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Solution Overview
Problem
Schottky barrier diodes have low withstand voltage and large leakage current under reverse bias, which limits their performance in applications requiring high switching speed and low power consumption.
Innovation Solution
The semiconductor device incorporates a P-type semiconductor region at the anode end to increase the area and proportion of the N-type semiconductor region, enhancing on-state current and suppressing leakage current under reverse bias, thereby increasing breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Schottky barrier diode uses conventional structure, then the switching speed is fast and power consumption is low, but the withstand voltage is low and leakage current is large
Solution Approach 1:
The anode region is segmented into multiple doped regions (first doped region, second doped region, third doped region) with different conductivity types and doping concentrations, creating distinct functional zones that separately address breakdown voltage enhancement and leakage current suppression
Solution Approach 2:
Different regions of the anode are assigned different local properties: the first doped region provides high doping concentration for breakdown voltage, the second doped region provides moderate doping for leakage control, and the third doped region provides low doping for Schottky barrier formation, allowing each region to optimize its specific function
2Power
If the N-type semiconductor region area is increased to enhance on-state current, then the forward conduction performance improves, but the leakage current under reverse bias increases
Solution Approach 1:
The N-type well region is configured with non-uniform doping distribution, having higher doping concentration near the Schottky contact for low forward resistance, and lower doping concentration deeper in the substrate for reduced reverse leakage, allowing simultaneous optimization of both on-state and off-state characteristics
Solution Approach 2:
The N-type region is divided into multiple doped regions with different conductivity types and concentrations, creating functional zones that separately optimize for forward current conduction and reverse leakage suppression
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 improves the electrical performance of Schottky barrier diodes by increasing on-state current, reducing leakage current to acceptable levels, and enhancing breakdown voltage.
Implementation Method 1
uses the layout of a P-type semiconductor region at an anode end to increase the area and the proportion of an N-type semiconductor region, thereby enhancing the on-state current of the SBD under forward bias
Implementation Method 2
A Schottky barrier diode (SBD) is a semiconductor device using Schottky barrier characteristics of a metal-semiconductor junction. Since the Schottky barrier is lower than the junction barrier of P-type and N-type semiconductors, compared with PN junction diodes, Schottky barrier diodes have lower turn on voltage and lower voltage drop under forward bias
Implementation Method 3
When the SBD is reverse biased, i.e., a negative voltage is applied to the anode and a positive voltage is applied to the cathode, the carriers are not conducted easily in the SBD
Data Source
AI summary
A semiconductor device includes a first well region disposed in a substrate and a first doped region buried in the first well region. The first doped region includes a middle portion and a peripheral portion. The first well region includes a continuous block directly above the middle portion. A second doped region is disposed in the first well region and directly above the peripheral portion. A third doped region is disposed in the first well region. A first isolation structure is located between the second doped region and the third doped region. An anode electrode is disposed above the substrate and electrically connected to the continuous block of the first well region. A cathode electrode is disposed above the substrate and electrically connected to the third doped region.