Semiconductor Source/Drain Protrusion with Titanium Barrier
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Solution Overview
Problem
Semiconductor devices with strained source/drain regions face challenges in maintaining low contact resistance and preventing material diffusion during annealing processes, which can lead to increased current leakage and power consumption.
Innovation Solution
A titanium-containing layer is deposited using a high-energy sputtering process to form a glue layer and barrier, increasing the contact area with the silicide layer and reducing diffusion by forming more stable TiSi2 and TiSiGe compounds instead of less stable TiGe compounds, thereby minimizing material diffusion and current leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If annealing processes are used to form silicide layers in strained source/drain regions, then conductivity in the channel region is improved, but material diffusion increases leading to current leakage
Solution Approach 1:
A titanium-containing layer is deposited over the source/drain regions to act as an intermediary barrier. This layer prevents direct diffusion of source/drain materials into the channel region during annealing, while still allowing the formation of stable silicide compounds (TiSi2, TiSiGe) that maintain low contact resistance and high conductivity.
Solution Approach 2:
The invention uses composite silicide compounds formed by the titanium-containing layer reacting with source/drain materials. The resulting TiSi2 and TiSiGe compounds combine the benefits of high stability (low diffusion) with high conductivity, resolving the contradiction between reliability and harmful diffusion effects.
2Area of stationary object
If high-energy sputtering is used to deposit titanium-containing layer, then contact area with silicide layer is increased, but energy consumption increases
Solution Approach 1:
The high-energy sputtering process is applied selectively and controllably to deposit the titanium-containing layer. The energy input is optimized to achieve sufficient contact area enhancement without excessive energy consumption, by controlling deposition parameters such as power, time, and material flux.
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 reduces contact resistance and current leakage, enhancing signal transfer efficiency and decreasing power consumption in semiconductor devices by forming a higher percentage of stable silicide compounds and minimizing material diffusion from the source/drain regions.
Implementation Method 1
A titanium-containing layer is deposited using a high-energy sputtering process to form a glue layer and barrier
Implementation Method 2
Annealing processes are used to form silicide layers in the strained S/D regions of semiconductor devices. The annealing process heats the semiconductor device in order to cause a reaction between at least silicon and a metallic material
Implementation Method 3
forming more stable TiSi2 and TiSiGe compounds instead of less stable TiGe compounds, thereby minimizing material diffusion
Data Source
AI summary
A device includes a source/drain (S/D) in a substrate and adjacent to a gate structure, wherein the S/D comprises a protrusion extending from a top surface of the S/D, and the protrusion has a tapered profile. The device further includes a contact plug electrically connected to the protrusion.