Semiconductor Source Drain Doping via Diffused Layer
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Solution Overview
Problem
Current methods for reducing contact resistance in semiconductor devices, such as the dopant segregated schottky (DSS) injection process, often damage the surfaces of source and drain contacts and require additional masks or photoetching processes, increasing complexity and cost.
Innovation Solution
A method involving the formation of a diffused layer with a higher doping density than the source and drain, followed by annealing, to increase doping density at the surfaces and reduce contact resistance, without using ion injection, thereby simplifying the process and reducing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion injection process is used to increase doping density at source and drain surfaces, then contact resistance is reduced, but surface damage occurs and additional masks or photoetching processes are required
Solution Approach 1:
A diffused layer is introduced as an intermediary between the source/drain and the ion injection process. This diffused layer serves as a protective mediator that receives the ion injection damage instead of the source/drain surfaces, while still enabling dopant segregation to reduce contact resistance. The diffused layer acts as a buffer zone that protects the critical source/drain regions from direct ion bombardment.
Solution Approach 2:
The doping process is segmented into two distinct stages: first forming the source and drain regions with baseline doping, then performing ion injection to create a separate diffused layer with higher doping density. This segmentation allows the ion injection to be targeted specifically at creating the low-resistance contact region without directly damaging the source/drain interfaces, as the diffused layer absorbs the harmful effects.
2Reliability
If ion injection process is used to increase doping density at source and drain surfaces, then contact resistance is reduced, but process complexity increases due to additional masks or photoetching
Solution Approach 1:
The formation of the diffused layer and the ion injection process are merged into a single integrated step. The diffused layer is formed through ion injection without requiring separate mask or photoetching processes, as the ion injection itself defines the diffused layer region. This merging eliminates the need for additional process steps while achieving both surface doping and contact resistance reduction.
3Reliability
If conventional doping methods are used to reduce contact resistance, then doping density is increased, but contact resistance reduction is insufficient
Solution Approach 1:
The doping density parameter is changed by introducing a diffused layer with significantly higher doping density than the source and drain regions. This parameter change creates a graded doping profile that optimizes contact resistance by providing a transition zone with varying doping concentrations, allowing better carrier transport while maintaining electrical control.
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, improves device performance, and eliminates the need for additional masks or photoetching processes, thereby simplifying the manufacturing process and reducing costs.
Implementation Method 1
the dopant in the diffused layer diffuses towards the surfaces of the source and/or the drain, so as to increase doping densities at the surfaces of the source and/or the drain
Implementation Method 2
performing an annealing processing after the diffused layer is formed
Data Source
AI summary
The present disclosure relates to the technical field of semiconductors, and discloses a semiconductor device and a manufacturing method therefor. The manufacturing method includes: providing a substrate; forming a source and a drain that are at least partially located in the substrate; forming a diffused layer on a surface of at least one of the source or the drain, where a conductivity type of the diffused layer is the same conductivity type as the source and the drain, and a doping density of a dopant contained in the diffused layer is separately greater than doping densities of dopants contained in the source and the drain; and performing an annealing processing after the diffused layer is formed. The present disclosure can increase a doping density at a surface of a source and/or a drain, helping to reduce a contact resistance, thereby improving performance of a device.