Semiconductor Air Gap Formation via Sacrificial Spacer
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Solution Overview
Problem
The formation of semiconductor device terminal air gaps is hindered by conductive contact material filling the air gaps during manufacture, leading to potential shorting of semiconductor device structures.
Innovation Solution
A method involving the formation of a sacrificial sidewall spacer followed by its removal after contact structure formation, allowing air gaps to be created without conductive material deposition in desired locations, utilizing selective etching processes to maintain dielectric material integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air gaps are formed before contact structure formation, then capacitive coupling is reduced, but conductive contact material fills the air gaps causing shorting
Solution Approach 1:
The sacrificial spacer is formed in advance before contact structures are created. This preliminary structure defines the air gap location and prevents conductive material from filling the gap, as the spacer physically blocks material deposition in that region during subsequent processing steps.
Solution Approach 2:
The sacrificial spacer acts as an intermediary element that temporarily occupies the space where the air gap will eventually form. This intermediary structure prevents harmful conductive material deposition while being removed after contacts are formed, leaving a clean air gap without contamination.
2Object-affected harmful factors
If air gaps are formed after contact structure formation, then conductive material filling is prevented, but capacitive coupling reduction is compromised
Solution Approach 1:
The sacrificial spacer is formed in advance before contact structures are created. This preliminary structure defines the air gap location and prevents conductive material from filling the gap, as the spacer physically blocks material deposition in that region during subsequent processing steps.
Solution Approach 2:
The sacrificial spacer acts as an intermediary element that temporarily occupies the space where the air gap will eventually form. This intermediary structure prevents harmful conductive material deposition while being removed after contacts are formed, leaving a clean air gap without contamination.
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 effectively prevents conductive material from filling air gaps, enhancing semiconductor device performance by reducing capacitive coupling and improving switching speeds and reducing RON (resistance) in transistors.
Implementation Method 1
utilizing selective etching processes to maintain dielectric material integrity
Data Source
AI summary
A method of making a semiconductor device with an air gap for a terminal of a semiconductor device includes forming a sacrificial sidewall spacer and removing the spacer after the formation of contact structures for the semiconductor device. The air gap is located in portions of the wafer where the sacrificial air gap was removed. Since the contacts are formed prior to the removal of the sacrificial spacers, air gaps can advantageously be formed without electrically conductive contact material undesirably being deposited in locations of the desired air gap.