Metallic Compound Layer Formation via Direct CVD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for forming metallic compound layers, such as silicide layers, face challenges including the need for annealing processes, potential plasma damage, difficulty in forming uniform layers on complex structures, and issues with controlling composition and crystal phase, especially for N-type and P-type MOSFET gate electrodes.
Innovation Solution
A method involving the direct formation of a metallic compound layer on a substrate by supplying a raw material gas containing a metal, heating the substrate to pyrolyze the gas, and controlling conditions to prevent metal deposition, allowing for a one-stage process that controls composition and crystal phase without annealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional sputtering method is used to form metal layer followed by annealing to form silicide, then silicide layer can be formed with controlled composition, but manufacturing process becomes complex and time-consuming due to multiple steps
Solution Approach 1:
The invention combines metal deposition and silicide formation into a single CVD process step. The metal precursor gas is deposited directly as a metallic compound layer that reacts with silicon to form silicide without requiring separate annealing, thus merging multiple process steps into one while maintaining composition control through gas flow rate and temperature parameters
Solution Approach 2:
The metal precursor is deposited in advance in a controlled manner with specific film thickness and composition by adjusting gas flow rates and substrate temperature. This preliminary deposition creates a metal layer with predetermined properties that will form the desired silicide composition after reaction, eliminating the need for subsequent annealing to achieve composition control
2Manufacturing precision
If high temperature annealing is used to form silicide layer, then desired silicide composition can be achieved, but plasma damage may occur to the substrate
Solution Approach 1:
The invention replaces the thermal annealing process with a chemical vapor deposition process. Instead of using high temperature thermal energy to drive silicide formation, a metal precursor gas is introduced that decomposes and reacts chemically at lower temperatures to form the metallic compound layer directly, substituting thermal-mechanical processing with chemical processing to avoid plasma and thermal damage
Solution Approach 2:
The invention changes the process parameters from high temperature annealing to controlled low temperature CVD deposition. By adjusting gas flow rate, pressure, and substrate temperature within specific ranges, the metal precursor decomposes and forms silicide at lower temperatures, achieving the same compositional control without the harmful high temperature plasma effects
3Quantity of substance
If conventional deposition methods are used, then metal layer can be formed, but uniform coverage on complex three-dimensional structures is difficult to achieve
Solution Approach 1:
The invention uses CVD gas delivery system where metal precursor is delivered through gas flow that can penetrate and conform to complex three-dimensional structures. The gaseous precursor distributes uniformly across the substrate surface including vertical sidewalls and recessed areas, achieving conformal coverage that liquid or solid deposition methods cannot provide on complex geometries
4Manufacturing precision
If multiple process steps are used to control crystal phase, then desired crystal structure can be achieved, but manufacturing cost and complexity increase
Solution Approach 1:
The invention controls crystal phase by adjusting CVD process parameters including substrate temperature, gas flow rate, and pressure during deposition. By optimizing these parameters within specific ranges, the metal precursor decomposes and reacts to form silicide with desired crystal structure directly during deposition, eliminating the need for separate crystal phase control steps and reducing manufacturing complexity
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
This approach enables the formation of metallic compound layers with controlled composition and crystal phase, reducing manufacturing costs and complexity, while avoiding plasma damage and ensuring uniform coverage on complex structures, including three-dimensional structures.
Implementation Method 1
heating the substrate to a temperature at which the raw material gas is pyrolyzed
Data Source
AI summary
A formation method of a metallic compound layer includes preparing, in a chamber, a substrate having a surface on which a semiconductor material of silicon, germanium, or silicon germanium is exposed, and forming a metallic compound layer, includes: supplying a raw material gas containing a metal for forming a metallic compound with the semiconductor material to the chamber; heating the substrate to a temperature at which the raw material gas is pyrolyzed; and forming a metallic compound layer by reaction of the metal with the semiconductor material so that no layer of the metal is deposited on the substrate. A manufacturing method of a semiconductor device employs this formation method of a metallic compound layer.