Back Electrode Interface Using NiSiV Layer for Adhesion Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The adhesion between the nickel silicide layer and the titanium film is low due to the lack of heat treatment, leading to potential electrode separation in semiconductor devices under high temperature and mechanical stress conditions.
Innovation Solution
A method involving the formation of a nickel silicide layer with a first metal having a lower thermal diffusion coefficient, followed by a heat treatment to react with n-type silicon, and subsequent deposition of a second metal layer, enhancing adhesion by segregating a metal with a lower diffusivity, such as vanadium, at the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a titanium layer is formed in contact with a nickel silicide layer without heat treatment, then the manufacturing process is simplified, but adhesion between the nickel silicide layer and the titanium film is low
Solution Approach 1:
The patent applies preliminary action by performing heat treatment before forming the titanium layer to pre-react the nickel silicide layer and create a favorable interface structure. This preliminary reaction modifies the nickel silicide layer to improve subsequent adhesion with the titanium film, preventing electrode separation issues.
Solution Approach 2:
The patent changes physical parameters by applying heat treatment to alter the thermal and structural state of the nickel silicide layer. The heat treatment modifies the diffusion characteristics and interface properties of the nickel silicide layer, enabling better adhesion with the titanium film without requiring additional interlayer materials.
2Power
If high power density and high junction temperature are implemented, then device performance is improved, but mechanical stress to each electrode joint due to film stress increases
Solution Approach 1:
The patent changes thermal and structural parameters through heat treatment to modify the stress characteristics of the nickel silicide layer. By controlling the heat treatment conditions, the patent optimizes the interface structure to reduce film stress and improve adhesion, enabling the device to withstand high power density and high junction temperature operations without electrode separation.
3Reliability
If continuous improvement in adhesion is pursued to suppress electrode separation, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent achieves improved adhesion by changing the thermal parameters through heat treatment of the nickel silicide layer. This parameter change modifies the interface properties and reduces film stress, improving adhesion reliability without adding complex process steps or additional material layers.
Solution Approach 2:
The patent applies self-service by utilizing the nickel silicide layer's own properties and its reaction behavior under heat treatment to improve adhesion. The nickel silicide layer self-modifies through heat treatment to create a favorable interface structure, eliminating the need for additional adhesion-promoting layers or complex processing.
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
Improves the adhesion between the semiconductor substrate and the back electrode, reducing the risk of electrode separation and enhancing the performance of the semiconductor device.
Implementation Method 1
reacting the n-type silicon contained in the semiconductor substrate with the nickel contained in the first metal layer to form a silicide layer in contact with the back surface of the semiconductor substrate by performing a heat treatment on the semiconductor substrate
Implementation Method 2
enhancing adhesion by segregating a metal with a lower diffusivity, such as vanadium, at the interface
Data Source
AI summary
Disclosed is a technique for enhancing adhesion between a semiconductor substrate and a back surface electrode covering the back surface thereof. In particular, the enhancing adhesion technique includes: providing a semiconductor substrate SB having a main surface and a back surface opposite to the main surface, the back surface including n-type silicon; forming a first metal layer on the back surface of the semiconductor substrate SB, the first metal layer including nickel and vanadium which has a thermal diffusion coefficient smaller than that of nickel; performing a heat treatment to the semiconductor substrate to react silicon contained in the semiconductor substrate with nickel contained in the first metal layer to form a NiSiV layer in contact with the back surface of the semiconductor substrate; and forming a second metal including titanium on the NiSiV layer.