Semiconductor Pattern Etching with Maskless Opening Formation
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Solution Overview
Problem
Existing methods for selective etching in semiconductor manufacturing are hindered by adjacent regions affecting the etching of target layers, leading to incomplete patterns due to interference and material collapse during the etching process.
Innovation Solution
A method involving a substrate with distinct regions, formation of trenches and sacrificial layers, and a maskless dry etching process to control the height differences and support structures, ensuring complete etching of target layers by minimizing material collapse and photoresist interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mask layer with opening pattern is formed before selective etching, then the target layer can be etched selectively, but adjacent regions may interfere with each other causing incomplete etching patterns
Solution Approach 1:
The substrate is divided into multiple independent regions (first region, second region, third region) with distinct trench structures in each region. This segmentation allows each region to be etched independently without interference from adjacent regions, solving the problem of incomplete etching patterns caused by regional interference.
Solution Approach 2:
Different regions are given different local structures: the first region has trenches with sacrificial layers on sidewalls, the second region has trenches without sacrificial layers, and the third region has no trenches. This local quality differentiation enables selective etching in each region according to its specific requirements, preventing adjacent region interference.
2Reliability
If the top surface of the fill layer in the first region is significantly higher than in the second region, then the fill layer can completely cover the sacrificial layer, but the fill layer may collapse and slide to the first region during etching
Solution Approach 1:
Trenches are pre-formed in the second region before the fill layer is deposited. These trenches act as material reservoirs that receive excess fill layer material during deposition, preventing the fill layer from becoming too thick and unstable in the first region, thereby avoiding collapse and sliding.
Solution Approach 2:
The trenches in the second region serve as intermediary structures that mediate the fill layer deposition process. They absorb excess material and create a gradual transition in fill layer height across regions, stabilizing the overall structure and preventing catastrophic failure in the first region.
3Productivity
If photoresist layer is used to form openings in the second and third regions, then those regions can be patterned, but the photoresist may fill the first opening and interfere with subsequent etching
Solution Approach 1:
The first opening is formed and cleared of photoresist before the photoresist layer is applied to form patterns in the second and third regions. This preliminary action prevents photoresist from filling the first opening, eliminating interference with subsequent etching processes while maintaining efficient patterning in all regions.
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
Ensures complete and accurate formation of etched patterns by preventing material collapse and photoresist interference, thereby achieving precise and efficient selective etching of target layers.
Implementation Method 1
perform a maskless dry etching process to remove a portion of the fill layer in the first region
Data Source
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AI summary
The embodiments of the present application provide a method for manufacturing a semiconductor structure, comprising: successively forming a target layer, a first mask layer, an isolation layer and an intermediate layer on a substrate, the intermediate layer in a first zone having at least one first recess, and the intermediate layer in a second zone having at least one second recess; forming filling layers, the filling layers filling the first recess and the second recess, the upper surfaces of the filling layers being higher than the upper surface of the intermediate layer, and the height difference between the top surface of the filling layer on the first zone and the top surface of the filling layer on the second zone being less than or equal to a first preset value; performing a maskless dry etching process to remove a part of the filling layer on the first zone until the top surface of a sacrificial layer is exposed; removing the sacrificial layer covering a side wall of the first recess so as to form a first opening on the first zone; and etching a part of the target layer by using the first opening, the remaining target layer constituting a target pattern. The embodiments of the present application are conducive to completely etching a target layer to form a required target pattern.