Ceramic Contact Isolation for Sub-20 Nm Semiconductor Trenches
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Advanced node complementary field-effect transistors face challenges in contact isolation, particularly in limited vertical space and material constraints, where existing methods like plasma-enhanced atomic layer deposition are unsuitable for narrow trench widths and curved contact profiles.
Innovation Solution
A method involving filling a trench with a sacrificial material, infiltrating it with a ceramic material, and removing the sacrificial material to form a thin, independent contact isolation with a flat top profile, suitable for trenches narrower than 20 nm, using a sacrificial material like spin-on-carbon and ceramic materials like Al2O3, with controlled etching and sequential infiltration synthesis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conformal Si3N4 liner is used for contact isolation in narrow trenches (12-14 nm), then the trench can be completely filled, but the approach becomes unsuitable and cannot provide proper isolation
Solution Approach 1:
A sacrificial material layer is deposited beforehand in the trench before forming the final contact isolation material. This preliminary layer serves as a placeholder that enables subsequent selective removal to create the desired isolation structure with proper dimensions and profile, solving the problem of complete trench filling leading to unsuitable isolation.
Solution Approach 2:
The method changes the physical and chemical parameters of the materials involved by using a sacrificial material with specific properties (organic material like spin-on-carbon) that can be selectively removed. This parameter change enables the formation of contact isolation with thickness below 10 nm, which cannot be achieved with conventional inorganic materials alone.
2Length of stationary object
If the contact isolation thickness is reduced to 10 nm or less for advanced nodes, then vertical space is optimized, but material choice and process control become more constrained
Solution Approach 1:
The method changes the material parameter space by introducing organic sacrificial materials (such as spin-on-carbon) that enable precise thickness control at the 10 nm scale. This parameter change expands the available material choices and process options for forming ultra-thin contact isolation structures that meet advanced node requirements.
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 enables effective contact isolation with a thickness of 10 nm or less, independent of the underlying contact profile, and provides stable, reliable performance in advanced technology nodes with controlled etch-back and economical manufacturing steps.
Implementation Method 1
infiltrating the sacrificial material with a ceramic material
Implementation Method 2
removing the sacrificial material
Data Source
AI summary
In a first aspect, the present disclosure relates to a method for forming a contact isolation for a semiconductor device, comprising: providing a semiconductor structure comprising a trench exposing a contact thereunder, filling a bottom of the trench with a sacrificial material, infiltrating the sacrificial material with a ceramic material, and removing the sacrificial material.