Contact Plug Formation Using Single Mask for Variable Resistance Memory
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Solution Overview
Problem
Existing electronic device fabrication processes face challenges in achieving desired overlap between contact plugs and securing patterning margins, leading to issues like short circuits and misalignment during the formation of vertical-type variable resistor elements.
Innovation Solution
The method involves forming contact plugs using a single mask to ensure simultaneous formation of overlapping contact holes, reducing etching height and misalignment, and using negative photoresist layers to control the formation of diagonal island-shaped patterns for precise patterning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If contact plugs are formed separately using multiple masks, then each contact plug can be individually positioned, but the alignment precision between overlapping contact plugs deteriorates and patterning margin is reduced
Solution Approach 1:
The patent merges the formation of multiple contact plugs into a single etching process using one mask pattern. The mask is designed with multiple opening regions that define all contact plug positions simultaneously, ensuring precise alignment between overlapping contact plugs while simplifying the manufacturing process by eliminating multiple separate patterning steps.
2Manufacturing precision
If etching height is increased to achieve desired overlap between contact plugs, then contact plug alignment can be improved, but the risk of short circuits between contact plugs increases
Solution Approach 1:
The patent performs preliminary actions by forming the mask pattern with precisely controlled opening regions before the etching process. The mask design pre-determines the exact positions and dimensions of all contact plugs, ensuring proper overlap alignment is achieved through controlled etching depth that stops at the substrate interface, thereby preventing short circuits while maintaining alignment precision.
3Adaptability or versatility
If multiple masks are used for forming contact plugs, then flexibility in contact plug positioning is improved, but the complexity of the fabrication process increases and productivity decreases
Solution Approach 1:
The patent creates a universal mask design that serves multiple functions simultaneously: it defines the positions of all contact plugs, controls their overlap alignment, and prevents short circuits through proper opening region design. This single mask pattern replaces multiple separate masks, maintaining positioning flexibility while significantly improving fabrication efficiency by reducing the number of patterning steps.
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 secures a patterning margin and prevents short circuits between contact plugs, improving the operational performance and reliability of electronic devices by ensuring accurate and efficient contact plug formation.
Implementation Method 1
using negative photoresist layers to control the formation of diagonal island-shaped patterns for precise patterning
Data Source
AI summary
The disclosed technology provides an electronic device and a fabrication method thereof. An electronic device according to an implementation of the disclosed technology may include: a first interlayer insulating layer formed over a substrate; first and second contact plugs passing through the first interlayer insulating layer to contact the substrate and alternately arranged to cross each other; a variable resistance element formed over the first interlayer insulating layer and coupled to the first contact plug; a second interlayer insulating layer formed over an entire structure including the first interlayer insulating layer; a third contact plug passing through the second interlayer insulating layer so as to be coupled to the variable resistance element, and a fourth contact plug passing through the second interlayer insulating layer so as to be contacted to the second contact plug; and conductive lines coupled to the third contact plug and the fourth contact plug, respectively.