Nitrogen-Graded Silicide Contacts for Low-Resistance Semiconductor Structures
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Solution Overview
Problem
The decreasing feature size of semiconductor structures leads to increased contact resistance due to smaller contact areas, resulting in performance issues such as slowed operation and deteriorated amplification characteristics, and current metal silicides suffer from line width effects and high resistance.
Innovation Solution
A semiconductor structure manufacturing method involving the deposition of an alloy layer on a silicon layer in a nitrogen-containing atmosphere, where the nitrogen concentration increases with deposition time, forming a metal silicide layer with varying nitrogen content to control silicification reactions and reduce resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal silicide is used to form ohmic contact, then contact resistance is reduced, but line width effect and high resistance problems still occur
Solution Approach 1:
The patent changes the chemical composition parameters of the contact layer by introducing nitrogen atoms during deposition. The nitrogen concentration is controlled to increase with deposition time, creating a gradient composition that optimizes both contact resistance and line width performance. This parameter change transforms the material properties to resolve the contradiction between low resistance and line width effect.
Solution Approach 2:
The patent creates a composite material structure by forming an alloy layer containing metal atoms and nitrogen atoms on the silicon layer. This composite structure combines the beneficial properties of metal silicide (low contact resistance) with the advantages of nitrogen incorporation (reduced line width effect), achieving a material that simultaneously addresses both issues.
2Productivity
If feature size is decreased to increase integration scale, then device density is improved, but contact resistance increases due to smaller contact area
Solution Approach 1:
The patent changes the compositional parameters of the contact layer by incorporating nitrogen atoms with a concentration that increases during deposition. This modification alters the electrical and structural properties of the contact material, enabling it to maintain low contact resistance even when contact area is reduced due to smaller feature sizes, thus resolving the contradiction between integration scale and contact resistance.
3Reliability
If nitrogen concentration increases with deposition time, then silicification reaction is optimized and resistance is reduced, but deposition time increases
Solution Approach 1:
The patent employs periodic action in the deposition process by controlling nitrogen concentration to increase progressively during deposition time. This time-dependent nitrogen incorporation creates optimal conditions for silicification reaction at different stages, achieving reduced resistance while managing deposition time through controlled periodic variation of nitrogen concentration.
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 effectively reduces contact resistance and prevents line width effects, thereby enhancing the performance of semiconductor structures by optimizing the silicification process and ensuring balanced reactions.
Implementation Method 1
performing deposition to form an alloy layer on the silicon layer, the deposition being performed in a nitrogen-containing atmosphere
Implementation Method 2
annealing the alloy layer and the silicon layer
Data Source
AI summary
The present application provides a semiconductor structure manufacturing method and two semiconductor structures. The manufacturing method includes: providing a substrate and a silicon layer, the substrate exposing a top surface of the silicon layer; performing deposition to form an alloy layer on the silicon layer, the deposition being performed in a nitrogen-containing atmosphere, and a concentration of nitrogen atoms in the nitrogen-containing atmosphere increasing with an increase in deposition time; and annealing the alloy layer and the silicon layer. In embodiments of the present application, an increase in the concentration of nitrogen atoms can control a silicification reaction of the alloy layer, thereby preventing a line width effect and reducing the resistance of the semiconductor structure.