Schottky Barrier Diode Backward Breakdown Voltage

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Solution Overview

Problem

The reliability of Schottky barrier diodes in LCD drivers is compromised due to a low breakdown voltage margin, limiting the effectiveness of screening processes and leading to defective semiconductor devices, as the breakdown voltage is insufficient to apply test voltages higher than the practically used voltage.

Innovation Solution

A semiconductor device configuration with a specific structure, including a first well region of opposite conductivity type, a second semiconductor region with higher impurity concentration, and conductor films for electrical coupling, which raises the backward breakdown voltage and enhances reliability by spreading the depletion layer, thereby improving the diode's rectification capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the breakdown voltage is increased to improve screening effectiveness, then testing capability is improved, but the risk of latch-up during normal operation increases

Engineering Contradiction:

Improvescreening effectivenessVSAvoidlatch-up risk

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent carefully adjusts the impurity concentration parameters to achieve an optimal balance. By setting specific impurity concentration ranges for different semiconductor regions, it increases the breakdown voltage for better screening while maintaining appropriate rectification characteristics to prevent latch-up during normal operation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates specialized regions with different impurity concentrations optimized for different functions. The first semiconductor region with higher impurity concentration provides robust rectification to prevent latch-up, while the overall structure achieves sufficient breakdown voltage for effective screening

Inventive Principle:

Principle #3Local quality

2Reliability

If the impurity concentration is increased to raise breakdown voltage, then screening capability is improved, but the forward voltage drop increases

Engineering Contradiction:

Improvebreakdown voltageVSAvoidforward voltage drop

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies different impurity concentrations to different regions: the first semiconductor region has higher impurity concentration to provide breakdown voltage and rectification, while the second semiconductor region has lower impurity concentration to minimize forward voltage drop. This localized differentiation optimizes both breakdown characteristics and forward conduction efficiency

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent optimizes the impurity concentration parameters by setting the first semiconductor region's concentration higher than the second's, creating a gradient that balances breakdown voltage enhancement with forward voltage drop minimization

Inventive Principle:

Principle #35Parameter changes

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 enhanced breakdown voltage margin allows for more effective screening and increased reliability of semiconductor devices by ensuring a larger voltage can be applied during testing without causing latch-up, thus reducing defective chip detection and improving overall device performance.

Implementation Method 1

The Schottky barrier diode comprises a junction of a metal material and a semiconductor material. Considering in particular a junction where there is a difference between the work function of the metal material and the electron affinity of the semiconductor material, the above difference in energy is held at a junction surface in a state of equilibrium, and they are bonded to each other in such a manner that both are made identical in Fermi level inside the material. Thus, a potential barrier equivalent to the original difference between the work function and the electron affinity occurs at the junction surface.

Methodology Applied

Scientific EffectSchottky barrier:

Implementation Method 2

Methodology Applied

Scientific EffectDepletion layer spreading:

Data Source

PatentUS8860169B2Semiconductor device comprising a Schottky barrier diode

Publication Date: 2014.10.14 RENESAS ELECTRONICS CORP

AI summary

The present invention aims to enhance the reliability of a semiconductor device equipped with a Schottky barrier diode within the same chip, and its manufacturing technology. The semiconductor device includes an n-type n-well region formed over a p-type semiconductor substrate, an n-type cathode region formed in part thereof and higher in impurity concentration than the n-well region, a p-type guard ring region formed so as to surround the n-type cathode region, an anode conductor film formed so as to integrally cover the n-type cathode region and the p-type guard ring region and to be electrically coupled thereto, n-type cathode conduction regions formed outside the p-type guard ring region with each separation portion left therebetween, and a cathode conductor film formed so as to cover the n-type cathode conduction regions and to be electrically coupled thereto. The anode conductor film and the n-type cathode region are Schottky-coupled to each other.