Selective Air Gap Deposition for Larger Semiconductor Gaps
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Solution Overview
Problem
Existing methods for forming air gaps in semiconductor devices often involve etching steps that can decrease device performance and limit the size of the air gap.
Innovation Solution
A method for selectively forming an air gap through atomic layer deposition (ALD) or chemical vapor deposition (CVD) processes, where a film is deposited horizontally on a substantially vertical surface, creating an air gap without the need for etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If etching steps are used to form air gaps, then air gaps can be created, but device performance decreases and air gap size is limited
Solution Approach 1:
Instead of removing material through etching to create air gaps, the invention deposits material selectively to form the air gaps. This inverted approach uses deposition rather than removal, allowing for larger air gap dimensions without compromising device performance, as the deposition process does not introduce the same harmful effects as etching.
Solution Approach 2:
The invention changes the process parameter from etching to selective deposition. By using atomic layer deposition (ALD) or chemical vapor deposition (CVD) with selective precursors, the process transforms from a material removal technique to a material addition technique, enabling larger air gap formation while maintaining device performance.
2Reliability
If protective liners are deposited on metal surfaces, then metal surfaces are protected, but air gap size decreases
Solution Approach 1:
The deposition process exhibits local quality by selectively depositing film material only on specific surfaces (such as dielectric surfaces) while intentionally avoiding metal surfaces. This spatial selectivity allows protective liners to be formed where needed without compromising air gap dimensions, as no deposition occurs on the metal surfaces that would reduce the air gap size.
Solution Approach 2:
The selective deposition process inherently provides the necessary protection through the deposition mechanism itself. By controlling the precursor selectivity, the process automatically deposits protective material only where required (on non-metal surfaces) while leaving metal surfaces exposed, eliminating the need for separate protective liner steps that would reduce air gap size.
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 allows for the creation of larger air gaps that can improve device performance by reducing the dielectric constant, increasing processing speed, and reducing power consumption and operating temperature.
Implementation Method 1
selectively depositing a film through a deposition method on the first surface
Implementation Method 2
selectively depositing a film through a deposition method on the first surface
Data Source
AI summary
A method for depositing a film to form an air gap within a semiconductor device is disclosed. An exemplary method comprises pulsing a metal halide precursor onto the substrate and pulsing an oxygen precursor onto a selective deposition surface. The method can be used to form an air gap to, for example, reduce a parasitic resistance of the semiconductor device.