Semiconductor Layout With Inclined Active Regions
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Solution Overview
Problem
Current semiconductor device layouts, such as 8F2 and 6F2, face limitations in increasing cell density and chip yield due to constraints on chip size, leading to issues like noise between lines and SAC failure in storage node contacts.
Innovation Solution
A layout with inclined active regions and device isolation films, where multiple active regions intersect with word and bit lines at specific angles, allowing for a higher density of capacitors and improved chip production, while maintaining sufficient gaps to prevent SAC failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the chip size increases to accommodate more memory cells, then the DRAM capacity increases, but the number of chips per wafer decreases leading to reduced yield
Solution Approach 1:
The active region is divided into multiple segments (first active region, right active region, left active region, upper active region, lower active region) arranged around a central device isolation film. This segmentation allows for more efficient space utilization and higher cell density within the same chip area, enabling more chips to be produced per wafer while maintaining high DRAM capacity.
Solution Approach 2:
The invention transitions from traditional linear arrangements to a radial/dimensional arrangement where active regions are positioned at different angular positions (0°, 60°, 120°, 180°, 240°, 300°) around the device isolation film. This dimensional change in layout optimization increases cell density without increasing chip size, thereby maintaining high yield.
2Quantity of substance
If the cell area is reduced to increase cell density, then more memory cells can be integrated in one wafer, but the gap between bit lines becomes insufficient causing SAC failure
Solution Approach 1:
The invention applies different design qualities to different parts of the cell structure. The active regions are positioned at specific angular intervals (60° apart) around the device isolation film, creating optimal local spacing. This local quality optimization ensures sufficient gap between bit lines for reliable SAC formation while maximizing overall cell density through the radial arrangement.
3Ease of manufacture
If the active regions are arranged in traditional rectangular or oval shapes, then the layout is simple to manufacture, but the cell density cannot be increased beyond 8F2 configuration
Solution Approach 1:
The invention employs an asymmetric radial arrangement of active regions around the device isolation film, with each active region positioned at specific angular positions (0°, 60°, 120°, 180°, 240°, 300°). This asymmetric layout breaks the traditional rectangular symmetry and enables higher cell density (achieving 6F2 or better) while remaining manufacturable through standard photolithography processes.
Data Source
AI summary
In a layout for a semiconductor device, each active region comprises a first active region, a right active region on the right side of the first active region, a left active region on the left side of the first active region, an upper active region on the upper side of the first active region and a lower active region on the lower side of the first active region, wherein the first active region, the right active region, the left active region, the upper active region and the lower active region each have an inclined portion having a bit-line contact region; and first and second portions having a storage node contact region, first and second ends formed on left and right ends of the inclined portion at a predetermined tilt angle with respect to the inclined portion, the active region being intersected by two word lines and one bit line.