Semiconductor Device Support Film Pattern for DRAM
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Solution Overview
Problem
In semiconductor devices, particularly DRAMs with 6F2 memory cells, the miniaturization of capacitors leads to a higher likelihood of lower electrode collapse during manufacturing due to reduced support film effectiveness, causing short-circuits and damage from prolonged exposure to etching chemicals, and challenges in accurately forming minute patterns with current exposure apparatuses.
Innovation Solution
A support film pattern is implemented with a first support pattern linearly extending in one direction and a second support pattern linearly extending in an orthogonal direction, with intervals and widths optimized to prevent electrode collapse, ensuring sufficient supporting strength and minimizing chemical exposure damage during wet etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If linear support films are used to prevent lower electrode collapse, then electrode stability is improved, but the support films are damaged by prolonged exposure to etching chemicals
Solution Approach 1:
The support film is divided into multiple separate linear support films arranged in a specific pattern, rather than using a single continuous support film. This segmentation allows each individual support film to be shorter, reducing its exposure time to etching chemicals while still providing adequate support to prevent electrode collapse.
Solution Approach 2:
The linear support films are positioned and configured before the wet etching process begins. The support patterns are designed with specific intervals and orientations to provide preliminary structural support that prevents electrode collapse during the subsequent etching process, while the segmented design ensures reduced chemical exposure.
2Manufacturing precision
If minute openings are formed in support films for wet etching, then electrode exposure is achieved, but pattern formation accuracy deteriorates
Solution Approach 1:
The support film pattern is segmented into linear regions with larger openings rather than minute point openings. This segmentation allows the use of larger, more easily formed openings that can be accurately patterned with current exposure apparatus while still achieving the necessary electrode exposure for wet etching.
3Area of stationary object
If capacitor size is reduced for miniaturization, then memory cell area is reduced, but electrode collapse likelihood increases
Solution Approach 1:
The support structure transitions from a planar two-dimensional support to a three-dimensional patterned support system. Linear support films are arranged in multiple orientations (first direction and second direction orthogonal to the first) with specific intervals, creating a three-dimensional support architecture that provides enhanced stability to miniaturized electrodes while occupying minimal area.
Solution Approach 2:
The support structure uses a composite pattern of linear support films arranged in orthogonal directions with different intervals. This composite arrangement combines the support benefits of multiple orientations, providing enhanced stability to miniaturized electrodes while maintaining compact area footprint.
Data Source
AI summary
A semiconductor device having a 6F2 memory cell whose size is defined by a numerical value of a design rule F, wherein: lower electrodes of capacitors included in the memory cell are supported by a support film; the support film is formed as a pattern combining a first support pattern (14x) linearly extending in a first direction and a second support pattern (14y) linearly extending in a second direction that crosses to the first direction; the support film is arranged such that the intervals of the first and second support patterns are both equal to or greater than 1.5F; and the interval of one of the first and second support patterns is greater than the interval of the other one of the first and second support patterns.