Nitrogen-Treated Silicon Pillars for Planar Contact Formation
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving precise control of element configuration due to undesired oxidation of silicon pillars, leading to rounding of edges and uneven surfaces, which results in reduced contact area and electrical disconnection or high electric resistance.
Innovation Solution
A method involving nitrogen treatment to prevent oxidation during the formation of oxide materials, ensuring a planar surface of silicon pillars by forming a residual nitrogen film that protects the silicon from oxidation, followed by conformal deposition of oxide and dielectric layers to maintain the planarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxide material is formed over silicon pillars, then electrical connection is established, but rounding of edges and uneven surfaces occur leading to reduced contact area and high resistance
Solution Approach 1:
A planarization layer is formed over the oxide material before trench formation. This preliminary action ensures that the surface is flattened prior to subsequent processing steps, preventing rounding effects from propagating to the trench structures and maintaining precise geometric control throughout the fabrication process.
Solution Approach 2:
The patent applies a nitridation treatment to the silicon pillars before oxide formation. This preliminary anti-action creates a nitrogen-rich surface layer that prevents excessive oxidation and rounding of the pillar edges during subsequent thermal processing, thereby maintaining surface planarity and contact area.
2Reliability
If conformal oxide deposition is performed on pillars, then complete coverage is achieved, but surface non-planarity is amplified
Solution Approach 1:
The planarization layer is deposited conformally over the oxide-coated pillars, providing complete coverage while simultaneously creating a flat upper surface. This preliminary planarization enables subsequent lithography and etching steps to proceed with precise geometric control.
Solution Approach 2:
The patent uses chemical mechanical polishing (CMP) to mechanically remove surface irregularities and achieve planarity. This process changes the surface topology parameter from non-planar to planar while maintaining the underlying conformal oxide structure.
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
The method improves device performance and product yield by preventing electrical disconnection and high resistance issues, ensuring a planar surface for silicon pillars.
Implementation Method 1
A nitridation is performed on the pillars
Implementation Method 2
prevent oxidation from occurring during formation of an oxide material
Implementation Method 3
An oxide material is deposited over the substrate to form a first oxide layer conformal to the plurality of pillars
Data Source
AI summary
The present application provides a semiconductor structure and a manufacturing method of the semiconductor structure. The semiconductor structure includes a substrate, a residual nitrogen, a first dielectric layer, a plurality of first contacts, and a plurality of second contacts. The substrate includes a plurality of pillars in an array region of the substrate, wherein a top surface of each of the plurality of pillars is a substantially planar surface. The residual nitrogen is partially disposed on sidewalls of the pillars proximal to the top surfaces of the pillars. The first dielectric layer surrounds each of the pillars. The plurality of first contacts extends from the top surfaces of the pillars into the pillars. The plurality of second contacts extends from the top surface of the first dielectric layer into the first dielectric layer.