High-Density Semiconductor Fin Formation via Selective Etch Masking
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Solution Overview
Problem
The existing methods for manufacturing semiconductor devices are costly due to the extensive operations associated with forming spacers, and they result in incomplete removal of dummy fins, leading to reduced fin density.
Innovation Solution
A method that alternately deposits first and second materials with different etch selectivities along the substrate, forming spacers to etch the substrate and create fins, thereby reducing spacer-related operations and allowing for high-density fin arrangement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional spacer formation operations are used to manufacture semiconductor devices, then fins can be formed, but manufacturing costs increase due to extensive spacer-related operations
Solution Approach 1:
The patent extracts and removes the dummy fins after they have served their purpose as spacers. The dummy fins are selectively removed using etch holes that allow etchant to reach and remove the dummy fins while leaving the active fins intact. This eliminates the need for separate spacer formation operations, reducing manufacturing cost and process complexity.
Solution Approach 2:
The dummy fins serve multiple functions: they act as spacers during the fin formation process, define the pitch between active fins, and can be selectively removed later. By making the dummy fins multi-functional, the patent eliminates the need for dedicated spacer structures and their associated formation operations, thereby reducing manufacturing cost.
2Productivity
If dummy fins are not completely removed, then manufacturing cost decreases, but fin density is reduced due to incomplete removal of dummy fins
Solution Approach 1:
The patent introduces etch holes as intermediary structures that enable selective removal of dummy fins. The etch holes provide a pathway for etchant to reach the dummy fins without affecting the active fins. After dummy fin removal, the etch holes are filled with dielectric material. This intermediary approach ensures complete and precise dummy fin removal, achieving high fin density without compromising manufacturing precision.
3Productivity
If fins are placed closer together to increase density, then fin density increases, but dummy fin removal becomes incomplete
Solution Approach 1:
The etch holes serve as reliable intermediaries that enable complete dummy fin removal even when fins are placed close together. The holes are positioned strategically to provide etchant access to dummy fins regardless of the reduced pitch between active fins. This ensures reliable dummy fin removal and maintains high fin density without compromising removal reliability.
Solution Approach 2:
The patent transitions from a two-dimensional planar approach to a three-dimensional approach by creating etch holes that extend vertically into the structure. This dimensional change allows etchant to access dummy fins from below, enabling complete removal even when horizontal spacing between fins is reduced, thereby maintaining high fin density with reliable 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
This approach decreases manufacturing costs by 33% and enables high-density fin placement, allowing fins in different cells to be collinear or parallel, even if cells have varying numbers of fins, without incomplete removal of dummy fins.
Implementation Method 1
depositing a first material on a substrate, depositing on the substrate a second material that has an etch selectivity different from an etch selectively of the first material
Implementation Method 2
etching the substrate using the spacer material as an etch mask to form fins
Data Source
AI summary
A method of manufacturing a semiconductor device includes depositing a first material on a substrate, depositing on the substrate a second material that has an etch selectivity different from an etch selectively of the first material, depositing a spacer material on the first and second material, and etching the substrate using the spacer material as an etch mask to form a fin under the first material and a fin under the second material.