High Aspect Ratio Gap Fill via Conformal Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Spin-on dielectrics exhibit low etch rates and develop undesirable air-pockets (voids) during the spin-on process, posing challenges in high volume manufacturing and reliability for semiconductor fabrication, especially in high aspect ratio structures.
Innovation Solution
Dielectric films or stacks are deposited using a low-temperature, conformal deposition process with oxygen-free reactants, which fill high-aspect ratio structures without damaging the photoresist, providing improved etch rates and minimizing voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If spin-on dielectrics are used to fill high aspect ratio structures, then gap fill capability is improved, but etch rate becomes low
Solution Approach 1:
The patent changes the material parameters by transitioning from spin-on dielectric materials to conformally deposited dielectric materials (such as PECVD or ALD dielectrics). This parameter change enables both adequate gap fill capability in high aspect ratio structures and improved etch rates for high volume manufacturing, resolving the contradiction between gap fill quality and manufacturing productivity.
2Manufacturing precision
If spin-on dielectrics are used during spin-on process, then gap fill is achieved, but air-pockets (voids) are generated
Solution Approach 1:
The patent changes the deposition process parameters from spin-coating to conformal deposition methods (PECVD or ALD). This eliminates the air-pocket formation inherent in spin-on processes while maintaining effective gap fill in high aspect ratio structures, as the conformal deposition process allows controlled material deposition without trapping air.
Solution Approach 2:
The patent replaces the mechanical spin-on coating process with a vapor-phase deposition process (PECVD or ALD). This substitution eliminates the mechanical spreading action that traps air pockets, allowing dielectric material to be deposited conformally without generating voids, while still achieving complete gap fill.
3Reliability
If low-temperature deposition is used to avoid photoresist damage, then photoresist integrity is improved, but deposition process constraints increase
Solution Approach 1:
The patent optimizes deposition parameters including temperature, pressure, and reactant composition to achieve conformal deposition at low temperatures. This allows photoresist integrity to be maintained while still achieving adequate etch rates and void-free gap fill, balancing the constraints of low-temperature processing with manufacturing requirements.
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
The solution enables effective gap fill in high-aspect ratio structures with minimal photoresist damage and reduced voids, enhancing the reliability and efficiency of semiconductor fabrication processes.
Implementation Method 1
Dielectric films or stacks are deposited using a low-temperature, conformal deposition process with oxygen-free reactants
Data Source
AI summary
The present disclosure describes a method of forming a dielectric layer or a dielectric stack on a photoresist layer while minimizing or avoiding damage to the photoresist. In addition, the dielectric layer or dielectric stack can till high-aspect ratio openings and can be removed with etching. The dielectric layer or dielectric stack can be deposited with a conformal, low-temperature chemical vapor deposition process or a conformal, low-temperature atomic layer deposition process that utilizes a number of precursors and plasmas or reactant gases.