Angled Ion Beam Irradiation for Recess Embedding
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Solution Overview
Problem
In semiconductor device manufacturing, the existing methods for forming fine recess portions often result in incomplete embedding of conductive materials due to air holes, and the use of ion beams to smooth corners can remove conductive barrier films, leading to disconnection issues and increased resistance.
Innovation Solution
A substrate processing method involving multiple angled ion beam irradiation steps to selectively remove deposition films from recess portions, ensuring complete embedding of materials while preserving conductive films on bottom, side walls, and upper end portions, thereby preventing disconnection and resistance issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ion beams are used to smooth corners of recess portions, then embedding of conductive material is improved, but conductive barrier films are removed leading to disconnection
Solution Approach 1:
The ion beam irradiation process is divided into multiple steps with different angles and conditions. The first step uses oblique irradiation to smooth corners, while subsequent steps use perpendicular or near-perpendicular irradiation to restore the barrier film, thereby segmenting the harmful effect from the beneficial effect
Solution Approach 2:
The barrier film restoration irradiation is performed as a preliminary or follow-up action to the corner-smoothing irradiation. By performing additional ion beam irradiation after the initial smoothing step, the patent prevents the harmful removal of barrier films while maintaining the beneficial corner smoothing effect
2Reliability
If conductive film is deposited again to suppress electromigration, then barrier property is improved, but wiring resistance increases
Solution Approach 1:
The patent replaces the mechanical deposition process (sputtering or CVD) with ion beam irradiation to form the barrier film. This substitution allows for more precise control of film thickness and composition, enabling the formation of an effective barrier film with minimal impact on wiring resistance
3Productivity
If fine recess portions are formed to increase element density, then device integration is improved, but conductive material embedding becomes incomplete
Solution Approach 1:
The ion beam irradiation parameters are optimized for local conditions within the fine recess portions. By controlling the irradiation angle, energy, and duration, the patent creates different processing zones: oblique irradiation targets the corner regions to smooth them, while perpendicular irradiation targets the bottom and side wall regions to ensure complete embedding and restore barrier films
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 effectively reduces protrusions within recess portions, prevents void formation, and maintains the integrity of conductive films, ensuring reliable connections and low resistance in semiconductor devices.
Implementation Method 1
irradiating the deposition film formed on the opening portion with a particle beam in a direction which forms a first angle with a direction perpendicular to an in-plane direction of the substrate, to remove part of the deposition film in a thickness direction
Data Source
AI summary
An object of the present invention is to provide a method which enable a material to be fully embedded into a recess portion with a deposition film left in the recess portion. A method in one embodiment comprises: a first irradiation step of irradiating a deposition film formed on an opening portion of a recess portion in a substrate with a particle beam in a direction at a first angle with respect to a substrate in-plane direction, to remove part of the deposition film in a thickness direction; and a second irradiation step of, after the first irradiation step, irradiating the deposition film with the particle beam in a direction at a second angle which is closer to perpendicular to the substrate in-plane direction than the first angle is, to remove part of the remaining deposition film in the thickness direction.