Remote Plasma Cleaning of Low-k Dielectric Films
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Solution Overview
Problem
Conventional in-situ plasma cleaning processes for low k dielectric films in semiconductor devices can damage the film, generate unwanted charged particles, and lead to carbon depletion, resulting in film degradation and increased capacitive coupling issues.
Innovation Solution
A remote plasma source with a magnetic filter is used to generate reactive radicals that clean the dielectric film surface, effectively removing contaminants while minimizing charged particle damage, preserving the film quality and preventing carbon depletion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional in-situ plasma is used for precleaning the dielectric layer, then contaminants are removed from the dielectric film surface, but the dielectric film surface is damaged or resputter and unwanted charged particles are generated
Solution Approach 1:
A remote plasma source is introduced as an intermediary component between the plasma generation zone and the substrate processing zone. The remote plasma source generates reactive species that are transported through a conduit to the processing chamber, allowing cleaning without direct plasma contact that causes damage. This mediator approach enables contaminant removal while protecting the dielectric film from resputtering and charged particle damage.
Solution Approach 2:
The patent replaces conventional direct plasma cleaning with a remote plasma chemical cleaning mechanism. Instead of using energetic ions and charged particles from direct plasma bombardment, the system uses chemically reactive neutral species generated remotely to clean the surface. This substitution of the cleaning mechanism eliminates the mechanical/physical damage associated with direct plasma while maintaining cleaning effectiveness.
2Reliability
If in-situ plasma cleaning is applied to carbon doped low k materials, then contaminants are removed, but carbon depletion or 'k loss' occurs and dielectric constant increases
Solution Approach 1:
The remote plasma source acts as an intermediary that delivers reactive species without the harmful effects of direct plasma exposure. The reactive species are generated in a remote chamber and transported to the substrate, enabling gentle chemical cleaning that removes contaminants without depleting carbon from the low k material. This preserves the dielectric constant and prevents k loss.
Solution Approach 2:
The patent changes the physical state and transport parameters of the reactive species. By generating plasma remotely and transporting the species through a conduit under controlled conditions, the system delivers reactive species at lower energies that clean contaminants without causing carbon depletion. This parameter change in species delivery enables selective contaminant removal while preserving the carbon-doped low k material composition.
3Productivity
If conventional plasma cleaning is used, then cleaning is achieved, but film degradation and defects occur resulting in increased cross-talk and RC delay
Solution Approach 1:
The remote plasma source serves as an intermediary system that decouples plasma generation from substrate processing. Reactive species are generated remotely and transported to the substrate surface, enabling efficient cleaning while avoiding the film degradation and defects caused by direct plasma exposure. This maintains manufacturing precision and film quality while achieving effective contaminant removal.
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 method improves the adhesion of conductive layers and enhances the reliability of semiconductor devices by maintaining the integrity of the low k dielectric film, reducing film degradation and unwanted cross-talk.
Implementation Method 1
generating a plurality of reactive radicals in a remote plasma source
Implementation Method 2
A remote plasma source with a magnetic filter is used to generate reactive radicals that clean the dielectric film surface
Implementation Method 3
flowing the reactive radicals from the remote plasma source into the process chamber through a passage having at least one magnet disposed adjacent the passage
Implementation Method 4
magnetically filtering the reactive radicals passing through the passage
Data Source
AI summary
An apparatus and a method of cleaning a dielectric film are provided in the present invention. In one embodiment, an apparatus of cleaning a dielectric film the apparatus includes a chamber body adapted to support a substrate therein, a remote plasma source adapted to provide a plurality of reactive radicals to the chamber body, a passage coupling the remote plasma source to the chamber body, and at least one magnet disposed adjacent the passage. In another embodiment, a method of cleaning a dielectric film that includes providing a substrate having an at least partially exposed dielectric layer disposed in a process chamber, generating a plurality of reactive radicals in a remote plasma source, flowing the reactive radicals from the remote plasma source into the process chamber through a passage having at least one magnet disposed adjacent the passage, and magnetically filtering the reactive radicals passing through the passage.