Back-Surface Electrode Structure for FRD Leakage Current Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The leakage current in semiconductor devices incorporating fast recovery diodes (FRDs) increases due to stress on the back-surface electrode structure, leading to defective products and reduced manufacturing yield.
Innovation Solution
Incorporating a stress relaxation layer made of aluminum, gold, silver, or copper as a main component in the back-surface electrode of the FRD to alleviate stress on the semiconductor substrate, thereby reducing leakage current and improving manufacturing yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional back-surface electrode structure is used in the FRD, then the manufacturing process is simple, but leakage current increases due to stress on the semiconductor substrate
Solution Approach 1:
The back-surface electrode is segmented into multiple functional layers: silicide layer, stress relaxation layer, barrier layer, and bonding layer. Each layer serves a specific function, with the stress relaxation layer specifically designed to reduce stress-induced leakage current while the other layers provide electrical, mechanical, and protective functions.
Solution Approach 2:
The back-surface electrode uses a composite structure combining different materials with complementary properties: silicide for low resistance, aluminum/gold/silver/copper for stress relaxation, and appropriate barrier materials for diffusion prevention. This composite approach solves the leakage current problem while maintaining electrical performance.
2Productivity
If stress relaxation layer is added to reduce leakage current, then manufacturing yield improves, but the number of manufacturing steps increases
Solution Approach 1:
The stress relaxation layer is formed during the initial back-surface electrode fabrication process, before the semiconductor chip is mounted on the lead. This preliminary incorporation of the stress relaxation function into the electrode structure itself prevents leakage current issues from the outset, improving manufacturing yield without requiring separate corrective steps later in the process.
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 stress relaxation layer effectively reduces leakage current, enhances manufacturing yield, and improves the performance of semiconductor devices by minimizing stress-related defects.
Implementation Method 1
a stress relaxation layer formed between the silicide layer and the barrier layer. The stress relaxation layer is made of a first metal film containing aluminum as a main component or a second metal film containing gold, silver, or copper as a main component
Data Source
AI summary
A semiconductor device includes a lead, a semiconductor substrate, a back-surface electrode provided between the semiconductor substrate and the lead, and a solder layer configured to connect the back-surface electrode and the lead. The back-surface electrode includes a silicide layer formed on a back surface of the semiconductor substrate, a bonding layer formed on the lead, a barrier layer formed on the bonding layer, and a stress relaxation layer formed between the silicide layer and the barrier layer. The stress relaxation layer is made of a first metal film containing aluminum as a main component or a second metal film containing gold, silver, or copper as a main component.