SiC Electrode Contact Formation With Metal Silicide Interface
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Solution Overview
Problem
The challenge in manufacturing semiconductor devices using silicon carbide is the high contact resistance between the silicon carbide layer and the metal electrode, which hinders the realization of low-loss and high-temperature operation.
Innovation Solution
A method involving ion implantation of p-type and carbon impurities into a silicon carbide layer, followed by heat treatment, oxidation, etching, and formation of metal silicide layers with specific metal elements like nickel, palladium, or chromium, to reduce carbon vacancies and enhance the acceptor concentration, thereby decreasing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a metal electrode is directly formed on a silicon carbide layer, then the device structure is simple, but the contact resistance between the silicon carbide layer and metal electrode is high
Solution Approach 1:
The patent introduces a metal silicide layer as an intermediary between the silicon carbide layer and metal electrode. This intermediate layer mediates the interface by reacting with silicon from the silicon carbide layer to form nickel silicide, nickel-rich nickel silicide, or chromium silicide, thereby reducing contact resistance while maintaining structural simplicity
Solution Approach 2:
The patent changes the chemical composition and phase structure of the interface layer by controlling the reaction between metal atoms and silicon carbide. By adjusting the metal-to-silicon ratio and heat treatment conditions, the interface transforms from a high-resistance direct contact to a low-resistance metal silicide layer with optimized electrical properties
2Reliability
If ion implantation and multiple heat treatments are performed to reduce carbon vacancies, then the contact resistance decreases, but the manufacturing process becomes complex
Solution Approach 1:
The patent performs preliminary ion implantation of metal atoms into the silicon carbide layer before forming the metal electrode. This preliminary action creates metal-rich regions that will subsequently react with silicon during heat treatment to form metal silicide layers, reducing the need for multiple corrective processing steps
Solution Approach 2:
The patent combines multiple functions into the metal silicide layer formation step: the metal implantation, the silicide layer formation through heat treatment, and the contact resistance reduction are all achieved through this integrated process, rather than as separate sequential steps
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 method effectively reduces contact resistance between the silicon carbide layer and the metal electrode, enabling low-loss and high-temperature operation of semiconductor devices.
Implementation Method 1
performing first ion implantation of ion-implanting a p-type impurity into a silicon carbide layer
Implementation Method 2
performing a first heat treatment for activating the p-type impurity
Implementation Method 3
performing a second heat treatment for causing the silicon carbide layer to react with the first metal film to form a metal silicide layer
Implementation Method 4
performing a first oxidation treatment of oxidizing the silicon carbide layer
Data Source
AI summary
Provided is a method for manufacturing a semiconductor device, the method including: performing first ion implantation ion-implanting a p-type impurity into a silicon carbide layer; performing second ion implantation ion-implanting carbon (C) into the silicon carbide layer; performing a first heat treatment activating the p-type impurity; performing a first oxidation treatment oxidizing the silicon carbide layer; performing an etching treatment etching the silicon carbide layer in an atmosphere containing hydrogen gas; forming a first metal film containing at least one metal element selected from the group consisting of nickel, palladium, platinum, and chromium; performing a second heat treatment causing the silicon carbide layer to react with the first metal film to form a metal silicide layer containing the at least one metal element; and forming a second metal film having a chemical composition different from a chemical composition of the first metal film.