Self-Aligned Dual Pattern Stack for Precise Interconnect Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in consistently forming accurate multiple patterns of structures due to misalignment and poor contact formation between structures, exacerbated by miniaturization, leading to issues like unwanted short circuits.
Innovation Solution
A method involving the use of a mask to shield a portion of gap fill material from plasma exposure, followed by selective etching and deposition of metal-containing substances in cavities formed by the etched gaps, allowing for precise formation of self-aligned patterns of vias, contacts, and lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multi-operation sequences of material deposition and removal are used to form nano-scale interconnect structures, then the structures can be formed with required complexity, but misalignment and poor contact formation occur between structures
Solution Approach 1:
The patent segments the gap fill material into multiple portions (first portion and second portion) with different plasma exposure histories. The first portion is exposed to plasma and the second portion is shielded, creating distinct etch selectivities that enable precise multi-pattern formation without misalignment
Solution Approach 2:
The patent applies preliminary plasma exposure to the gap fill material before final patterning. By exposing the first portion of the gap fill material to plasma in advance and shielding the second portion, the method prepares different etch response characteristics that ensure accurate alignment during subsequent etching operations
2Productivity
If structures are miniaturized to improve IC performance and reduce cost, then the overall size of IC is reduced and number of circuit elements increases, but misalignment and poor contact formation between structures is exacerbated
Solution Approach 1:
The patent applies local quality by creating spatially varying plasma exposure within the gap fill material. The first portion receives plasma treatment while the second portion remains shielded, giving each region distinct properties that enable precise control of etching behavior at miniaturized dimensions
Solution Approach 2:
The patent changes the plasma exposure parameter of the gap fill material to create different etch selectivities. By controlling which portions are exposed to plasma and which are shielded, the method achieves precise alignment control even as structure dimensions are miniaturized
3Ease of manufacture
If conventional etching processes are used on uniformly exposed gap fill material, then the process is simple, but unwanted short circuits occur between adjacent structures
Solution Approach 1:
The patent creates local quality differences in the gap fill material by selectively exposing different portions to plasma. The first portion with plasma exposure has different etch characteristics than the shielded second portion, enabling precise etching that prevents short circuits while maintaining process feasibility
Solution Approach 2:
The plasma-exposed and shielded portions of the gap fill material act as intermediaries that control the etching process. The differential plasma exposure creates etch selectivity that serves as a mediator between the etching process and the final pattern fidelity, preventing short circuits
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 consistent and accurate formation of multiple patterns with improved alignment and reduced short circuits, enhancing semiconductor device performance and reliability.
Implementation Method 1
exposing the workpiece to a plasma. The first portion of the gap fill material is shielded from the plasma by the mask, and the second portion of the gap fill material is exposed to the plasma
Implementation Method 2
exposing the first portion of the gap fill material and the second portion of the gap fill material to an etching process. The etching process selectively removes the first portion of the gap fill material versus the second portion of the gap fill material
Implementation Method 3
depositing a first metal-containing substance in the first cavity to create a first metal-containing feature
Data Source
AI summary
A substrate processing method includes creating a mask on a top surface of a workpiece. A first portion of a gap fill material is overlaid by the mask and a second portion of the gap fill material is exposed through an opening in the mask. The method further includes exposing the workpiece to a plasma. The method further includes performing a first etching of the first portion of the gap fill material to create a first cavity while the second portion of the gap fill material remains in place, depositing a first metal-containing substance in the first cavity, performing a second etching of the second portion of the gap fill material to create a second cavity while the first metal-containing substance remains in place, and depositing a second metal-containing substance in the second cavity.