Atomic Layer Removal for Semiconductor Dimension Control
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Solution Overview
Problem
As semiconductor device dimensions shrink, conventional photolithographic patterning methods struggle to reliably construct small device structures due to deformation or breakage of patterned photoresists, making it difficult to achieve precise dimensions in integrated circuits.
Innovation Solution
A method involving the formation of a mask over a semiconductor substrate, followed by partial etching and incremental removal of atomic layers using free radicals to control the formation of device structures, allowing for precise shaping of surfaces to smaller dimensions than conventional methods can reliably attain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithographic patterning is used to define features, then manufacturing process is simple and well-established, but manufacturing precision deteriorates at small dimensions due to photoresist deformation or breakage
Solution Approach 1:
The patent segments the material removal process into multiple discrete atomic layer removal steps, each removing a controlled number of atomic layers (e.g., 1-5 layers per step). This segmentation allows precise control over final feature dimensions by accumulating small, controlled removals rather than relying on a single patterning step, thereby achieving high manufacturing precision without photoresist deformation
Solution Approach 2:
The patent performs preliminary actions by first forming a mask pattern with conventional photolithography (which remains reliable for defining the general pattern), then uses atomic layer removal to precisely define the final feature dimensions. This preliminary patterning followed by atomic layer removal allows the robustness of conventional methods to be combined with the precision of atomic-level control
2Productivity
If feature dimensions are reduced to increase packing density, then productivity and device capacity improve, but manufacturing precision deteriorates due to photoresist breakage
Solution Approach 1:
By segmenting the etch process into multiple atomic layer removal steps with intermediate measurements, the patent achieves precise control over small feature dimensions even as overall device packing density increases. Each segment removes a known number of atomic layers, allowing cumulative precision that enables reliable manufacturing of smaller features
Solution Approach 2:
The patent replaces the mechanical/photochemical photoresist patterning system with a chemical vapor deposition-based atomic layer removal system for the critical dimension definition step. This substitution eliminates photoresist deformation issues while enabling precise control of small features, thereby supporting higher packing densities with maintained manufacturing precision
3Productivity
If continuous etching process is used for material removal, then productivity is high with rapid material removal, but manufacturing precision deteriorates due to inability to control atomic layer thickness
Solution Approach 1:
The patent employs periodic action by alternating between atomic layer removal steps and measurement steps. Each removal step removes a controlled number of atomic layers, followed by a measurement step to verify the current surface position. This periodic cycle continues until the target dimension is achieved, providing both precision control and acceptable productivity through efficient use of each removal cycle
Solution Approach 2:
The patent implements feedback control by measuring the surface position after each atomic layer removal step and using this information to determine whether to continue removal. The measurement feedback ensures that the final feature dimensions meet specifications, while the controlled removal rate maintains acceptable productivity by avoiding unnecessary removal steps
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
Enables the precise control and formation of semiconductor device structures with very small dimensions, overcoming the limitations of conventional etch methods by allowing for precise control over the removal of atomic layers, thus improving the reliability of small device structures in integrated circuits.
Implementation Method 1
removing thicknesses of one to several atomic diameters of atoms that comprise the layer from the lateral surfaces and the vertical surfaces that are located under the mask
Data Source
AI summary
A method for manufacturing a semiconductive device comprising forming a mask for a semiconductive device structure over a layer of a semiconductor substrate and partially etching the layer to form lateral and vertical surfaces. Thicknesses of one to several atomic diameters of atoms that comprise said layer are removed from the lateral surfaces and the vertical surfaces that are located under the mask to form a target dimension of a semiconductive device structure.