Semiconductor Contact Doping via Surface Annealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices are miniaturized, contact resistance increases due to dopant deactivation and depletion in near-surface layers caused by native oxide formation, etch and surface-cleaning treatments, and metal deposition processes, leading to reduced doping density and increased heterogeneity.
Innovation Solution
The process involves surface or near-surface doping of contact surfaces, followed by an annealing process to enhance doping concentration and preserve electrical current quality, which includes forming a trench to expose raised source/drain contacts, applying surface doping, and completing contact metallization before annealing to facilitate solid-state diffusion of dopants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If semiconductor devices are miniaturized to reduce device size, then device dimensions are reduced, but contact resistance increases due to dopant deactivation and depletion in near-surface layers
Solution Approach 1:
The patent applies local quality by creating a doping-rich zone specifically in the near-surface layer of the contact region, while the bulk semiconductor material maintains its original doping concentration. This localized enhancement of doping concentration at the contact surface compensates for dopant deactivation and depletion caused by miniaturization, thereby reducing contact resistance without requiring overall device enlargement.
2Ease of manufacture
If conventional doping processes are used in miniaturized devices, then manufacturing simplicity is maintained, but doping density decreases and heterogeneity increases due to process-related deactivations
Solution Approach 1:
The patent employs preliminary action by performing surface doping treatments on the semiconductor contact regions before final metallization and device assembly. This pre-treatment ensures that the near-surface layers are pre-loaded with dopants that will compensate for subsequent dopant deactivation during manufacturing processes, thereby maintaining doping density uniformity without complicating the overall manufacturing流程.
3Area of moving object
If contact area is reduced due to miniaturization, then device footprint is reduced, but contact resistance increases due to greater surface-area-to-volume ratio effects
Solution Approach 1:
The patent applies parameter changes by modifying the doping concentration parameter specifically in the near-surface layer of the contact region. By creating a doping-rich zone with elevated dopant concentration at the contact surface, the electrical conductivity is enhanced, which compensates for the increased surface-area-to-volume ratio effects caused by reduced contact area, thereby maintaining low contact resistance in miniaturized devices.
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 reduces contact resistance by maintaining sufficient doping density and homogeneity in near-surface layers, counteracting the effects of miniaturization and process-related deactivations, thereby improving electrical current conduction.
Implementation Method 1
annealing process to enhance doping concentration... annealing process to facilitate solid-state diffusion of dopants
Data Source
AI summary
A die includes a semiconductive prominence and a surface-doped structure on the prominence. The surface-doped structure makes contact with contact metallization. The prominence may be a source- or drain contact for a transistor. Processes of making the surface-doped structure include wet-vapor- and implantation techniques, and include annealing techniques to drive in the surface doping to only near-surface depths in the semiconductive prominence.