Polysilicon Interlayer for Semiconductor Wire Bond Adhesion
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Solution Overview
Problem
The reliability of semiconductor apparatuses is compromised due to variations in bonding strength between wires and aluminum electrodes, particularly because of weak adhesion between barrier metals and interlayer films, leading to exclusion of aluminum during wire bonding.
Innovation Solution
A semiconductor apparatus design featuring a polysilicon layer under the interlayer film, with the barrier metal directly on both the polysilicon and interlayer film, acts as an anchor to reduce aluminum exclusion and enhance bonding strength by improving adhesion between the barrier metal and polysilicon layer, thereby stabilizing the wire bond.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an interlayer film is partially provided under the aluminum electrode to suppress aluminum exclusion, then bonding strength variation is reduced, but adhesion between barrier metal and interlayer film becomes weak
Solution Approach 1:
A polysilicon layer is introduced as an intermediary between the barrier metal and the interlayer film. This intermediate layer serves as a bridge that provides strong adhesion to both the barrier metal and the interlayer film, resolving the adhesion weakness problem while maintaining the aluminum exclusion suppression function of the interlayer film structure
Solution Approach 2:
The structure employs a composite multi-layer configuration consisting of barrier metal, polysilicon layer, and interlayer film. This composite structure combines the advantages of each material: the barrier metal provides electrical functionality, the polysilicon layer provides strong adhesion, and the interlayer film provides mechanical anchoring to suppress aluminum exclusion during bonding
2Reliability
If a barrier metal layer is formed under the aluminum electrode, then electrical properties are improved, but adhesion between barrier metal and interlayer film becomes weak
Solution Approach 1:
The polysilicon layer acts as an intermediary between the barrier metal and interlayer film, providing strong adhesion interfaces on both sides. This allows the barrier metal to maintain its electrical functionality while the polysilicon layer compensates for the weak adhesion between barrier metal and interlayer film
3Manufacturing precision
If the interlayer film is partially provided in the bonding region, then aluminum exclusion is suppressed, but adhesion between barrier metal and interlayer film is weak
Solution Approach 1:
The polysilicon layer is positioned between the barrier metal and interlayer film to provide strong adhesion. This allows the interlayer film to be partially provided in the bonding region for manufacturing precision while the polysilicon layer ensures strong adhesion of the barrier metal
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 configuration reduces variation in bonding strength and improves the reliability of semiconductor apparatuses by suppressing aluminum exclusion and enhancing adhesion, ensuring consistent and robust connections.
Implementation Method 1
Adhesion between the barrier metal and the polysilicon layer is stronger than adhesion between the barrier metal and the interlayer film
Data Source
AI summary
A semiconductor apparatus including a bonding region in which a wire is bonded, includes: a semiconductor substrate; an oxide film provided on a principal surface of the semiconductor substrate in the bonding region; a polysilicon layer provided on the oxide film; an interlayer film partially provided on the polysilicon layer; a barrier metal directly provided on the polysilicon layer and the interlayer film; and an electrode provided on the barrier metal.