Non-volatile Memory Device Simultaneous Hole Formation
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Solution Overview
Problem
The existing methods for fabricating non-volatile memory devices are complex due to the separate formation of channel holes and contact holes, which can lead to incomplete depth formation due to higher aspect ratios, complicating the integration process.
Innovation Solution
A method that simultaneously forms channel holes and contact holes during the fabrication process, using alternately stacked sacrificial layers to create a recess for the gate electrode, thereby simplifying the process and ensuring proper depth formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If channel holes and contact holes are formed separately, then the fabrication process can be performed step-by-step, but the process complexity increases and depth formation becomes incomplete due to higher aspect ratios
Solution Approach 1:
The patent combines the formation of channel holes and contact holes into a single simultaneous etching process. By using a unified mask layer and performing one etching operation instead of separate sequential operations, the method reduces process complexity while ensuring complete depth formation. The simultaneous formation eliminates the aspect ratio issues that arise in sequential processes, as both holes are created in the same etching cycle with optimized parameters.
Solution Approach 2:
The patent applies preliminary action by forming a unified mask layer that defines both channel hole and contact hole patterns before the etching process. This pre-configured mask layer enables the subsequent single etching step to create both hole types simultaneously with precise depth control, avoiding the need for multiple masking and etching cycles that would increase complexity and improve depth completeness.
2Device complexity
If channel holes and contact holes are formed simultaneously, then the fabrication process is simplified, but the precision of individual hole formation may be compromised
Solution Approach 1:
The patent applies local quality by using a unified mask layer with spatially varying patterns that define different hole types at different locations. The mask layer contains regions with different openings - some areas define channel holes with specific dimensions while other areas define contact holes with different dimensions. This allows simultaneous etching with location-specific precision, where each hole type receives optimized etching conditions based on its local requirements.
Solution Approach 2:
The patent segments the mask layer into distinct regions that define different hole patterns. The mask layer is divided into first mask regions that define channel holes and second mask regions that define contact holes. This segmentation enables the single etching process to treat different hole types differently based on their location, maintaining precision for each hole type while achieving simultaneous formation through one process step.
3Manufacturing precision
If separate formation methods are used for channel holes and contact holes, then each hole type can be optimized independently, but the integration process becomes complicated
Solution Approach 1:
The patent applies universality by designing a single mask layer that serves multiple functions - it defines both channel hole patterns and contact hole patterns in one structure. This universal mask layer enables both types of holes to be formed through a single etching process, maintaining the ability to optimize each hole type's dimensions and positions while eliminating the need for separate formation processes and simplifying the overall integration.
Data Source
AI summary
A method for fabricating a non-volatile memory device is provided. The method includes forming a channel hole and a first contact hole simultaneously, several times, in order to achieve a desired a high aspect ratio.