SiC Metal Silicide Contact Smoothing for Low-Roughness Surfaces
Solution Overview
Problem
Semiconductor devices with metal silicide layers often exhibit high surface roughness and protrusions, which reduce conductivity and hinder the formation of reliable electrical contacts, leading to suboptimal device performance.
Innovation Solution
A method involving the formation of a metal silicide layer on a silicon carbide (SiC) substrate, where first thermal energy is applied to form the silicide layer and subsequent second thermal energy is used to reduce surface roughness, combined with a laser shot process to smooth the surface, resulting in a semiconductor device with improved electrical contact quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thermal energy is applied to form a metal silicide layer from metal and silicon carbide, then the metal silicide layer is formed, but the surface roughness increases and protrusions form
Solution Approach 1:
A metal layer is deposited on the silicon carbide substrate before silicide formation, creating a controlled interface that prevents excessive surface roughness and protrusion formation during the silicidation process. This preliminary metal layer acts as a buffer that maintains surface integrity while enabling reliable electrical contact.
Solution Approach 2:
The surface roughness is controlled by adjusting parameters including the metal layer thickness, deposition conditions, and silicidation temperature. By optimizing these parameters, the surface roughness is maintained below critical thresholds that would compromise electrical contact quality, thereby resolving the contradiction between forming the silicide layer and maintaining surface integrity.
2Manufacturing precision
If multiple laser shots are performed to smooth the metal silicide layer surface, then surface roughness is reduced, but the manufacturing process time increases
Solution Approach 1:
The metal layer is deposited with controlled thickness and uniformity before silicide formation, creating a foundation that requires minimal subsequent surface treatment. This preliminary control reduces the number of laser shots needed to achieve the desired surface roughness, thereby maintaining productivity while achieving the required manufacturing precision.
Solution Approach 2:
The surface roughness is primarily controlled by adjusting deposition and silicidation parameters rather than relying on extensive post-processing laser shots. By optimizing the metal layer thickness, deposition rate, and silicidation temperature, the surface is prepared in advance to require fewer corrective laser treatments, thus balancing manufacturing precision with production efficiency.
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 approach results in a semiconductor device with reduced surface roughness and protrusions, enhancing electrical conductivity and overall device performance by ensuring better contact between metal layers and the semiconductor substrate.
Implementation Method 1
First thermal energy may be directed to the first surface of the first layer to form a metal silicide layer from the metal of the first layer and silicon of the SiC layer
Implementation Method 2
Second thermal energy may be directed to the first surface of the metal silicide layer to reduce a surface roughness of the first surface of the metal silicide layer
Implementation Method 3
A plurality of laser shots may be performed on the first surface of the electrical contact formation region of the first layer to form a metal silicide layer from the metal of the first layer and silicon of the SiC layer
Data Source
AI summary
A semiconductor device and a method of manufacturing a semiconductor are provided. In an embodiment, a method of manufacturing a semiconductor device is provided. A first layer is formed over a silicon carbide (SiC) layer. The first layer has a first surface distal the SiC layer and a second surface proximal the SiC layer. The first layer includes a metal. First thermal energy may be directed to the first surface of the first layer to form a metal silicide layer from the metal of the first layer and silicon of the SiC layer. The metal silicide layer has a first surface distal the SiC layer and a second surface proximal the SiC layer. Second thermal energy may be directed to the first surface of the metal silicide layer to reduce a surface roughness of the first surface of the metal silicide layer