Semiconductor Interlayer Insulator Void Formation via Polymer Depolymerization
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Solution Overview
Problem
Existing methods for reducing the relative dielectric constant of interlayer insulating films in semiconductor devices are inefficient in creating voids with desired shapes and sizes, leading to inconsistent parasitic capacitance and mechanical strength.
Innovation Solution
A method involving the formation of a polymer film with urea bonds around structures on a substrate, followed by shape adjustment and depolymerization to create voids, using a temporary sealing film to desorb monomers and form voids with arbitrary shapes, thereby reducing the relative dielectric constant and improving electrical and mechanical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a void is formed as an embedment failure when embedding a recess, then the relative dielectric constant of the interlayer insulating film is reduced, but the shape and size of the void cannot be precisely controlled
Solution Approach 1:
A polymer film is formed around the structures before the interlayer insulating film is deposited. This preliminary polymer film serves as a sacrificial template that defines the precise shape and size of the void that will later be created. The polymer film is deposited conformally on the recessed structures, ensuring uniform coverage and precise geometric control before any void formation occurs.
Solution Approach 2:
The polymer film undergoes depolymerization through heating, transitioning from a solid polymer state to gaseous monomers that escape through the temporary sealing film. This phase transition creates the void space while maintaining the shape defined by the original polymer film structure, enabling precise void geometry control.
2Manufacturing precision
If a void is formed as an embedment failure, then the relative dielectric constant is reduced, but the mechanical strength becomes inconsistent
Solution Approach 1:
The polymer film is formed as a sacrificial template with the exact desired void geometry before the interlayer insulating film is deposited. This ensures that the voids have precise and consistent shapes and sizes, which directly controls the parasitic capacitance and mechanical strength characteristics of the final device structure.
Solution Approach 2:
The depolymerization temperature and heating conditions are carefully controlled to ensure complete removal of the polymer film while maintaining the structural integrity of the surrounding interlayer insulating film and conductive structures. This parameter control ensures consistent void formation without compromising mechanical strength.
3Ease of manufacture
If conventional methods are used to create voids, then the process is simple, but the voids cannot achieve desired shapes and sizes
Solution Approach 1:
The polymer film is deposited conformally on the recessed structures before the interlayer insulating film is formed. This preliminary polymer layer acts as a sacrificial template that defines the precise void geometry. The conformal deposition process is simple to implement using standard CVD or spin coating techniques, yet it provides excellent shape control.
Solution Approach 2:
The polymer film serves as an intermediary sacrificial material that temporarily occupies the space where the void will eventually form. It is easily deposited, maintains precise geometric definition during the subsequent processing steps, and can be completely removed through depolymerization to create the desired void structure.
4Manufacturing precision
If a polymer film is formed around structures and then depolymerized, then voids with arbitrary shapes can be created, but additional process steps are required
Solution Approach 1:
The polymer film is formed as a preliminary sacrificial template around the conductive structures before the interlayer insulating film is deposited. This allows the void shape to be precisely defined in advance. The polymer film deposition is integrated into the existing manufacturing flow and uses standard deposition techniques.
Solution Approach 2:
The polymer film is removed through thermal depolymerization, where heating causes the polymer to decompose into volatile monomers that escape through the temporary sealing film. This phase transition from solid polymer to gas creates the void space cleanly without requiring mechanical removal steps, simplifying the overall process despite the additional polymer deposition step.
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 method allows for the stable creation of voids with desired shapes and sizes, reducing parasitic capacitance and enhancing the mechanical strength of semiconductor devices by effectively adjusting the dielectric constant of the interlayer insulating films.
Implementation Method 1
heating the polymer film to depolymerize the polymer into the plural types of monomers
Implementation Method 2
desorb the plural types of depolymerized monomers through the temporary sealing film
Data Source
AI summary
There is provided a method of manufacturing a semiconductor device, including: forming a polymer film, which is a film of a polymer having a urea bond generated by polymerization of plural types of monomers, around a plurality of structures provided on a substrate and including a first material; adjusting a shape of the polymer film; forming a temporary sealing film on the polymer film to cover the polymer film; and heating the polymer film to depolymerize the polymer into the plural types of monomers and desorb the plural types of depolymerized monomers through the temporary sealing film.