Chemical Planarization for Non-Abrasive Microchip Fabrication
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Summary
Problems
Chemical Mechanical Polishing (CMP) is a harsh, expensive, and yield-reducing process that cannot be used for certain microfabrication steps, such as transistor fabrication, especially when gate oxide is exposed, and is not suitable for creating planar surfaces required in photolithography.
Innovation solutions
A chemical planarization process using a developable planarization material, such as silicon-based developer soluble bottom anti-reflective coating (Si-DBARC), which is coated and then selectively dissolved with a solubility-changing agent to achieve a planar surface without mechanical polishing, allowing for simultaneous patterning and etching at multiple heights.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If Chemical Mechanical Polishing (CMP) is used to planarize the wafer surface, then a planar surface is achieved, but the process becomes harsh, expensive, and reduces yield
Why choose this principle:
The patent replaces the mechanical polishing component of CMP with a purely chemical process. A planarization layer made of developer-soluble material (such as DBARC) is deposited and then chemically dissolved using a solubility-changing agent, eliminating mechanical abrasion while achieving the desired planar surface. This substitution resolves the contradiction by removing the harsh mechanical action that reduces yield while maintaining the planarity function.
Principle concept:
If Chemical Mechanical Polishing (CMP) is used to planarize the wafer surface, then a planar surface is achieved, but the process becomes harsh, expensive, and reduces yield
Why choose this principle:
The patent changes the chemical parameters of the planarization layer by using a material whose solubility can be altered by a solubility-changing agent. The planarization layer is made of developer-soluble material that becomes soluble when exposed to the solubility-changing agent, enabling controlled chemical removal. This parameter change allows the process to achieve planarization without mechanical stress, thereby improving yield while maintaining surface quality.
Application Domain
Data Source
AI summary:
A chemical planarization process using a developable planarization material, such as silicon-based developer soluble bottom anti-reflective coating (Si-DBARC), which is coated and then selectively dissolved with a solubility-changing agent to achieve a planar surface without mechanical polishing, allowing for simultaneous patterning and etching at multiple heights.
Abstract
A chemical planarization process described herein can be used for planarizing a substrate without using mechanical abrasion. A developable planarization material can be applied to a substrate having a non-planar topography, such that a planar surface results. The resulting planarization layer can cover existing structures on the substrate. A top portion of the planarization layer can be solubilized using a solubility-changing agent, and then the soluble portion can be removed thereby slimming a height of the planarization material to a target value, which can be a top surface of a tallest underlying structure. With the substrate planarized, additional patterning operations can be executed.