Self-Aligned Semiconductor Contacts for Active Region Misalignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices become more integrated, the complexity of contact formation increases, leading to misalignment issues between contacts and active regions, which reduces mass production margins due to decreased design rules and available space for contacts.
Innovation Solution
A semiconductor device design featuring self-aligned contacts, where a first mask and a second mask with a greater top surface height are used to form an active region with an oblique shape, allowing for precise alignment and reduced misalignment between contacts and the active region through a specific manufacturing method involving trench formation, insulating layer deposition, and conductive layer filling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the degree of integration of semiconductor devices increases, then the design rules for components decrease and device density improves, but the contact forming process becomes increasingly complicated and misalignment between contacts and active region increases
Solution Approach 1:
The method performs preliminary actions by forming masks at specific heights before contact formation. The first mask is formed at a first height and the second mask at a second height greater than the first height, establishing a predetermined spatial relationship that guides subsequent contact hole formation and ensures accurate alignment with the active region
Solution Approach 2:
The invention introduces a vertical dimension (height) as an additional degree of freedom for alignment control. By positioning masks at different heights (first height and second height), the method creates a three-dimensional self-alignment structure that automatically guides contact formation without requiring complex lateral alignment processes
2Area of stationary object
If the space for contact is decreased to increase integration density, then more devices can be packed, but misalignment between contact and active region increases and mass production margin decreases
Solution Approach 1:
The method enables self-alignment where the contact structure automatically aligns with the active region through the predetermined spatial relationship between masks at different heights. This self-service mechanism eliminates the need for complex external alignment processes and maintains high precision even as contact dimensions are reduced
Solution Approach 2:
The invention changes the alignment parameter from lateral positional relationships to vertical height relationships. By controlling the heights of masks (first height and second height) rather than their lateral positions, the method achieves precise alignment in reduced contact spaces while maintaining mass production robustness
Data Source
AI summary
A semiconductor device includes: an active region defined by a device isolation layer formed in a substrate; a word line configured to cross the active region, the word line extending in a first direction and being formed in the substrate; a bit line extending in a second direction perpendicular to the first direction on the word line; a first contact connecting the bit line to the active region; a first mask for forming the active region, the first mask being formed on the active region; and a second mask of which a height of a top surface thereof is greater than a height of a top surface of the active region, the second mask covering the word line, wherein the active region has a bar shape that extends to form an acute angle with respect to the first direction.