Semiconductor Storage Device Contact Formation via Inversion
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Solution Overview
Problem
The increasing density of memory cells in DRAM arrays complicates the manufacturing process, making it difficult to decrease costs while maintaining yield, as existing methods are complex and inefficient in forming storage node contacts.
Innovation Solution
A manufacturing method where conductive patterns are formed first, followed by isolation patterns between them, simplifying the process and increasing yield by avoiding the need for a patterned oxide layer and reducing material layer damage during etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to form storage node contacts, then the manufacturing process can be completed, but the process becomes complex and manufacturing yield decreases
Solution Approach 1:
The patent inverts the conventional sequence by forming conductive patterns first and then forming isolation patterns between them, rather than forming isolation patterns first and then creating contacts through them. This reversal simplifies the manufacturing process and improves yield by eliminating the need for complex patterned oxide layer formation and reducing etching damage to material layers
Solution Approach 2:
The patent extracts and eliminates the unnecessary patterned oxide layer step from the conventional manufacturing process. By forming isolation patterns directly between conductive patterns, the method removes a complex intermediate step that contributed to process complexity and yield issues while still achieving the required isolation function
2Manufacturing precision
If conventional etching methods are used, then storage node contacts can be formed, but damage occurs to other material layers
Solution Approach 1:
The patent performs preliminary actions by forming the conductive patterns and isolation patterns before performing the etching back process. The isolation patterns are formed as protective structures that prevent damage to underlying material layers during subsequent etching operations, while still allowing precise contact formation through the controlled etching back of the conductive patterns
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 method simplifies the manufacturing process and increases yield by forming storage node contacts through a self-aligned process, maximizing contact width and minimizing damage to other material layers, thus enhancing the efficiency and reliability of semiconductor storage device production.
Implementation Method 1
performing an etching back process to the conductive patterns for decreasing the thickness of the conductive patterns
Data Source
AI summary
A manufacturing method of a semiconductor storage device includes forming a plurality of bit line structures on a semiconductor substrate and forming a plurality of storage node contacts disposed between the bit line structures. The method of forming the storage node contacts includes forming a plurality of conductive patterns on the semiconductor substrate followed by performing an etching back process to the conductive patterns for decreasing a thickness of the conductive patterns. The manufacturing method further includes forming a plurality of isolation patterns between the conductive patterns, wherein the isolation patterns are formed after forming the plurality of conductive patterns and before the etching back process. According to the present invention, the storage node contacts are formed by first forming the conductive patterns and then forming the isolation patterns between the conductive patterns, so as to simplify manufacturing process and increase process yield.