Contact Plug Liner Structure for Low-Resistance Semiconductor Contacts
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Solution Overview
Problem
In semiconductor devices, the increasing grain size of conductive patterns in contact plugs leads to higher resistance, affecting the overall electrical characteristics of the device.
Innovation Solution
The semiconductor device incorporates a contact plug structure comprising a barrier pattern, a first liner with varying grain sizes, a second liner in an amorphous metal state, and a conductive pattern on top, optimized through physical vapor deposition (PVD) and atomic layer deposition (ALD) processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the grain size of the conductive pattern is decreased, then the resistance of the conductive pattern increases, but the contact plug can be manufactured with finer patterns
Solution Approach 1:
The first liner is divided into two portions with different grain sizes: a first portion with smaller grain size for fine pattern manufacturing precision, and a second portion with larger grain size for lower resistance. This local differentiation allows each portion to optimize for its specific function while being part of the same continuous liner structure.
Solution Approach 2:
The first liner is segmented into two distinct portions along the vertical direction, with the first portion extending from the barrier pattern and the second portion extending from the first portion. This segmentation enables independent optimization of grain sizes in different regions to simultaneously achieve fine patterning and low resistance.
2Device complexity
If a single-layer liner structure is used, then the manufacturing process is simpler, but the resistance control and grain size optimization are insufficient
Solution Approach 1:
The liner structure is segmented into a first liner with two portions and a second liner, creating a multi-layer structure that enables differentiated grain size control. The first liner's two portions provide vertical gradient in grain size, while the second liner adds another functional layer, together achieving superior resistance control.
Solution Approach 2:
The contact plug employs a composite liner structure combining multiple material layers with different properties. The first liner and second liner are made of different materials or have different microstructures, creating a composite system where each layer contributes specific properties for optimal electrical performance.
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 configuration results in a contact plug with low resistance due to the large grain size of the conductive pattern, thereby enhancing the electrical characteristics of the semiconductor device.
Implementation Method 1
forming a first liner layer on the barrier pattern and the upper sidewall of the opening by a physical vapor deposition (PVD) process
Implementation Method 2
forming a second liner layer on the first liner layer by an atomic layer deposition (ALD) process
Data Source
AI summary
The semiconductor device includes a substate, a gate structure on the substrate, a source/drain layer on the substrate adjacent to the gate structure, and a contact plug. The contact plug includes a barrier pattern on the source/drain layer, a first liner on the barrier pattern, a second liner on the first liner and including a metal, a conductive pattern on the second liner and including the metal. The first liner includes a first portion extending along a surface of the barrier pattern and having a first grain size, and a second portion extending from the first portion disposed on an end portion of the barrier pattern, the second portion being in contact with the first portion and having a second grain size greater than the first grain size.