Inorganic Spacer Formation for Array Double Patterning
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Solution Overview
Problem
Current semiconductor wafer processing techniques face challenges in efficiently defining features with precise control over array and periphery areas using traditional patterning and etching methods, which often require multiple masks and steps, leading to increased costs and complexity.
Innovation Solution
A method involving a patterned organic mask with an inorganic layer deposition process, where the inorganic layer thickness is greater over the periphery area than the array area, allowing for the formation of inorganic spacers in the array area while protecting the periphery area, enabling a single mask to be used for both end-of-line and periphery etching, thereby reducing the need for multiple lithography steps and associated costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional patterning and etching methods are used to define features with precise control over array and periphery areas, then feature definition is achieved, but multiple masks and steps are required leading to increased costs and complexity
Solution Approach 1:
The patent combines the array area definition and periphery area definition into a single patterned organic mask, eliminating the need for separate masks. The inorganic layer is deposited once and then selectively removed through a single etch-back step, merging multiple patterning and etching operations into one integrated process flow.
Solution Approach 2:
The patterned organic mask is segmented into two functional regions: the array area portion that will be removed to define features, and the periphery area portion that will be retained to protect surrounding structures. This segmentation allows a single mask to perform multiple functions that traditionally required separate masks.
2Device complexity
If a single patterned organic mask is used for both array and periphery areas, then the number of masks is reduced, but selective removal of the mask in the array area while protecting the periphery area becomes challenging
Solution Approach 1:
An inorganic layer is deposited as an intermediary material over the entire patterned organic mask. This inorganic layer serves as a protective mediator that can be selectively removed: in the array area, it is removed to expose and allow subsequent removal of the organic mask, while in the periphery area, it remains to protect the organic mask from removal.
Solution Approach 2:
The inorganic layer is given different thicknesses in different regions: a first thickness over the array area and a second (greater) thickness over the periphery area. This local quality differentiation enables selective etch-back removal where the thinner inorganic layer in the array area is completely removed to expose the organic mask, while the thicker inorganic layer in the periphery area remains to protect it.
3Manufacturing precision
If multiple etch and strip steps are used to process array and periphery areas separately, then precise control is achieved, but processing time and costs increase
Solution Approach 1:
Multiple separate etching and stripping operations are merged into a single etch-back step. The inorganic layer is etched back in one operation to simultaneously expose the organic mask in the array area while leaving it protected in the periphery area, eliminating the need for multiple sequential steps.
Solution Approach 2:
The inorganic layer is deposited in advance over the entire patterned organic mask before any etching or stripping operations. This preliminary deposition creates a protective structure that enables subsequent selective removal operations to be performed in a single step rather than requiring multiple sequential operations.
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 allows for precise feature definition with reduced costs by eliminating the need for separate masks and subsequent etch and strip steps, achieving cost savings and improved processing efficiency in semiconductor wafer fabrication.
Implementation Method 1
A plasma processing chamber is provided, comprising a chamber wall forming a plasma processing chamber enclosure, at least one antenna for providing power to the plasma processing chamber enclosure for sustaining a plasma
Data Source
AI summary
A method for forming an array area with a surrounding periphery area, wherein a substrate is disposed under an etch layer, which is disposed under a patterned organic mask defining the array area and covers the entire periphery area is provided. The patterned organic mask is trimmed. An inorganic layer is deposited over the patterned organic mask where a thickness of the inorganic layer over the covered periphery area of the organic mask is greater than a thickness of the inorganic layer over the array area of the organic mask. The inorganic layer is etched back to expose the organic mask and form inorganic spacers in the array area, while leaving the organic mask in the periphery area unexposed. The organic mask exposed in the array area is stripped, while leaving the inorganic spacers in place and protecting the organic mask in the periphery area.