Substrate Film Deposition Cycles for Selectivity and Step Coverage
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Solution Overview
Problem
The challenge in semiconductor manufacturing is to improve step coverage of films formed on substrates during selective growth, as existing methods struggle to achieve uniformity and selectivity, particularly with the miniaturization of devices.
Innovation Solution
A technique involving the supply of a modifying agent to form an inhibitor layer on specific surfaces of a substrate, followed by a cycle of precursor and reactant supply, where process conditions are adjusted after a predetermined number of cycles to optimize film formation on the second surface while suppressing growth on the first surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If selective growth is performed to form a film on a specific surface, then film selectivity is improved, but step coverage deteriorates
Solution Approach 1:
An inhibitor layer is formed on the first surface before the selective growth process begins. This preliminary action prevents film formation on the first surface during subsequent processing, enabling selective film growth on the second surface while improving step coverage through controlled inhibitor layer removal
Solution Approach 2:
The process conditions are changed after a predetermined number of cycles by adjusting at least one parameter (temperature, pressure, gas flow rate, or treatment time) to uniformly remove and invalidate the inhibitor layer on the second surface, thereby improving step coverage while maintaining film selectivity
2Device complexity
If process conditions are kept constant during cyclic film formation, then process simplicity is improved, but film thickness uniformity deteriorates
Solution Approach 1:
The film formation is performed through cyclic processes where precursor and reactant are supplied alternately multiple times. This periodic action allows controlled film growth with improved thickness uniformity while maintaining reasonable process complexity
Solution Approach 2:
Process conditions are changed after a predetermined number of cycles to uniformly remove the inhibitor layer and achieve desired film thickness uniformity, balancing process simplicity with manufacturing precision
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 approach enhances step coverage, wafer in-plane film thickness uniformity, and surface roughness by uniformly removing and invalidating the inhibitor layer on the second surface, thereby improving film characteristics and productivity.
Implementation Method 1
supplying a modifying agent to a substrate including a first surface and a second surface to form an inhibitor layer on the first surface and at least a portion of the second surface
Implementation Method 2
forming a film on the second surface by performing a cycle a predetermined number of times, the cycle including (b1) supplying a precursor to the substrate and (b2) supplying a reactant to the substrate
Data Source
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AI summary
There is provided a technique, which includes: (a) supplying a modifying agent to a substrate including a first surface and a second surface to form an inhibitor layer on the first surface and at least a portion of the second surface; and (b) forming a film on the second surface by performing a cycle a predetermined number of times, the cycle including (b 1) supplying a precursor to the substrate and (b2) supplying a reactant to the substrate, wherein in (b), a process condition per cycle up to an n-th cycle is set to be different from a process condition per cycle on and after an (n+1)-th cycle, wherein n is an integer of 1 or 2 or more.