Gate Pattern Formation via Selective Etching Modification
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Solution Overview
Problem
In semiconductor device manufacturing, the formation of gate patterns using double patterning techniques often results in deviations from the designed pattern, leading to inaccurate control over the shape and size of gate patterns, which adversely affects device performance as device sizes decrease.
Innovation Solution
A method is introduced where the etching characteristics of the gate material layer are selectively modified at positions where gaps are to be formed, differing from the characteristics at remaining positions, through processes like implantation or oxidization, allowing for more precise control over the gate pattern formation by reversing the order of patterning processes and using different etching characteristics for selective removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional double patterning technique is used to form gate patterns, then the gate pattern can be formed through two patterning processes, but the obtained trimming slot patterns deviate from the designed patterns due to margin of trimming slot patterning, leading to inaccurate control of gate pattern shape and size
Solution Approach 1:
The patent applies preliminary action by performing a first etching process to form gate material bars with different etching characteristics at positions where gaps will later be formed. This preliminary modification of etching characteristics allows the second patterning process to accurately define gap positions without the margin deviation problems that affect trimming slot patterning in conventional methods.
Solution Approach 2:
The patent implements local quality by creating non-uniform etching characteristics within the gate material layer. Specifically, the gate material layer is treated to have different etching characteristics at positions where gaps are to be formed compared to other positions. This local differentiation enables precise control of gap positions during the second etching process, eliminating the pattern deviation issues.
2Ease of manufacture
If trimming slot etching is performed using deviated trimming slot patterns, then the gate pattern can be formed, but the deviation between the obtained gate pattern and the designed pattern becomes more remarkable and difficult to modify
Solution Approach 1:
The patent performs preliminary etching to form gate material bars with differentiated etching characteristics before the final gap formation step. This preliminary action ensures that when the second patterning process defines the gap positions, the etching proceeds accurately according to the designed pattern without the cumulative deviations that occur when trimming slot patterns are already deviated.
Solution Approach 2:
The patent changes the etching characteristics parameter of the gate material layer at specific positions where gaps will be formed. By modifying the etching characteristics (such as etch rate or etch selectivity) locally, the patent ensures that the second etching process accurately removes material at the intended gap positions, preventing the pattern deviation that occurs in conventional methods.
3Productivity
If conventional double patterning is used, then the gate pattern formation process can be completed, but additional leveling processes are required and costs increase
Solution Approach 1:
The patent merges the gap formation process with the second patterning process. By designing the second resist layer to directly define gap positions and using the pre-modified etching characteristics of the gate material layer, the patent combines what would traditionally require separate trimming slot formation and leveling steps into a single integrated process, reducing overall process complexity.
Solution Approach 2:
The patent changes the etching characteristics parameter of the gate material layer to enable selective removal at gap positions during the second etching process. This parameter modification allows the etching process itself to achieve both gap formation and surface leveling in one step, eliminating the need for additional leveling processes required in conventional methods.
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 enables more accurate control over the shape and size of the gate pattern, improving semiconductor device performance by reducing deviations and enhancing process flexibility, while also eliminating the need for additional leveling processes and reducing costs.
Implementation Method 1
making an etching characteristic of the gate material layer at least at positions where the gaps are to be formed different from an etching characteristic of the gate material layer at remaining positions; performing implantation or oxidization on the gate material layer at least at the positions of the gate material layer where the gaps are to be formed
Implementation Method 2
making an etching characteristic of the gate material layer at least at positions where the gaps are to be formed different from an etching characteristic of the gate material layer at remaining positions; performing implantation or oxidization on the gate material layer at least at the positions of the gate material layer where the gaps are to be formed
Data Source
AI summary
This disclosure relates to a method of forming a gate pattern and a semiconductor device. The gate pattern comprises a plurality of parallel gate bars, and each gate bar is broken up by gaps. The method comprises: making an etching characteristic of a gate material layer at least at positions where the gaps are to be formed different from that at remaining positions; forming a plurality of parallel openings in a second resist layer; performing a first etching process on the gate material layer with the second resist layer as a mask, wherein portions of the gate material layer at least at the positions where the gaps are to be formed are selectively left; and performing a second etching process on the gate material layer so as to selectively remove the portions. This method can more accurately control the shape and size of the gate pattern.