Selective Silicon Deposition Using Plasma Treat-Etch Cycles
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Solution Overview
Problem
As device sizes in semiconductor fabrication approach the 10 nm regime, traditional patterning processes using photolithography become increasingly challenging, leading to non-precise patterning and degraded device performance, necessitating the development of methods for selectively depositing films onto specific surfaces.
Innovation Solution
A multi-stage deposition-treatment-etch process using silane and plasma to deposit silicon films on substrates with different surfaces, where the silicon film is modified by treatment plasmas of Ar, He, or H2, and then selectively etched to leave the film only on the desired surface, allowing for repeated cycles to achieve precise film deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional photolithography is used for patterning, then the process is well-established and relatively simple, but patterning precision degrades and device performance deteriorates at 10 nm regime
Solution Approach 1:
The patent replaces traditional photolithography (optical/mechanical system) with a plasma-based selective deposition system. The deposition system uses plasma chemistry and electric field control to achieve patterning, substituting the optical projection and chemical development process with direct plasma-phase material deposition that is electrically and chemically controlled.
Solution Approach 2:
The patent employs parameter changes in plasma chemistry (gas composition, pressure, power, temperature) to control deposition selectivity and rate. By adjusting plasma parameters such as RF power, gas flow rates, and chamber pressure, the system achieves precise control over where and how material is deposited, enabling 10 nm-scale patterning precision.
2Manufacturing precision
If selective deposition is used to deposit features, then patterning precision improves, but the process becomes more complex and expensive
Solution Approach 1:
The patent makes the deposition system multi-functional by integrating deposition, treatment, and etching capabilities in a single plasma-based platform. The same reactor chamber performs multiple functions: depositing conformal films, treating surfaces to modify nucleation properties, and etching to remove material from non-target areas, eliminating the need for separate processing equipment.
Solution Approach 2:
The patent uses periodic cycling of deposition and etching steps to build up the desired pattern. Multiple deposition-etch cycles are performed sequentially, with each cycle adding material to target surfaces while removing it from non-target surfaces, progressively refining the pattern through repeated periodic actions rather than requiring a single complex step.
3Length of moving object
If multiple patterning technologies are used, then feature size reduction is achieved, but fabrication processes become complicated and expensive
Solution Approach 1:
The patent applies local quality by creating different surface properties at different locations on the substrate. Treatment plasma is used to modify the nucleation characteristics of specific surface regions, making them more or less receptive to deposition. This local modification of surface quality enables selective deposition without requiring multiple separate patterning steps.
Solution Approach 2:
The patent introduces treatment plasma as an intermediary step between deposition and etching. This intermediary treatment modifies the surface chemistry and morphology to control where subsequent deposition will occur, acting as a mediator that directs material placement without requiring direct mechanical or optical patterning tools.
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 enables precise and selective deposition of silicon films on specific surfaces, improving patterning accuracy and device performance by leveraging differences in nucleation and etch rates between surfaces, thereby simplifying and reducing the complexity and cost of semiconductor fabrication.
Implementation Method 1
chemical vapor deposition (CVD) as well as plasma enhanced chemical vapor deposition (PECVD)
Implementation Method 2
The silicon film is exposed to a treatment plasma to modify a structure, composition or morphology of the silicon film
Implementation Method 3
The film is etched from the first surface and the second surface to remove substantially all of the film from the second surface
Data Source
AI summary
Methods for selective silicon film deposition on a substrate comprising a first surface and a second surface are described. More specifically, the process of depositing a film, treating the film to change some film property and selectively etching the film from various surfaces of the substrate are described. The deposition, treatment and etching can be repeated to selectively deposit a film on one of the two substrate surfaces.