Epitaxial Semiconductor Device Shallow Junction Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The continuous scaling down of semiconductor devices leads to significant short channel effects, which are challenging to address due to substrate damage caused by ion implantation, requiring low-energy ion implantation and ultra-short annealing, and additional annealing processes to remove damages.
Innovation Solution
A method involving the growth of epitaxial layers on a substrate, forming a sacrificial gate stack, selective etching, in-situ doping, and using spacers to form source/drain regions, which avoids ion implantation and ultra-short annealing by controlling the thickness and doping of the epitaxial layers to create shallow extension regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If low-energy ion implantation is used to form shallow extension regions, then short channel effects are suppressed, but substrate damage occurs requiring additional annealing processes
Solution Approach 1:
The patent replaces the mechanical ion implantation process with a chemical epitaxial growth process. Instead of physically implanting ions into the substrate (which causes damage), the extension regions are formed through in-situ doped epitaxial growth where dopants are incorporated during the crystal growth process itself. This substitution eliminates substrate damage while maintaining precise depth control through growth time and temperature parameters.
Solution Approach 2:
The patent changes the fundamental process parameters from ion implantation (energy, dose, angle) to epitaxial growth (temperature, time, gas flow, precursor ratios). By controlling the epitaxial growth conditions, the junction depth and doping concentration are precisely controlled without causing substrate damage, thus resolving the contradiction between manufacturing precision and substrate damage.
2Productivity
If conventional ion implantation is used, then source/drain regions can be formed, but ultra-short annealing is required to activate implanted ions and remove damage
Solution Approach 1:
The patent merges the formation of extension regions and source/drain regions into a single epitaxial growth process. The in-situ doped epitaxial growth simultaneously creates both regions with appropriate doping profiles, eliminating the need for separate ion implantation and annealing steps. This reduces process complexity while maintaining or improving productivity.
Solution Approach 2:
The patent extracts and eliminates the harmful ion implantation step from the manufacturing process. By using epitaxial growth instead, the need for ultra-short annealing to activate ions and remove damage is eliminated, simplifying the process flow and reducing the number of required process steps.
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 allows for the formation of shallow source/drain extension regions with precise control, reducing substrate damage and eliminating the need for ultra-short annealing, thereby improving semiconductor device manufacturing processes and performance.
Implementation Method 1
growing a first epitaxial layer on a substrate
Implementation Method 2
growing and in-situ doping a second epitaxial layer on the substrate
Data Source
AI summary
A semiconductor device and a method for manufacturing the same are provided. In one embodiment, the method comprises: growing a first epitaxial layer on a substrate; forming a sacrificial gate stack on the first epitaxial layer; selectively etching the first epitaxial layer; growing and in-situ doping a second epitaxial layer on the substrate; forming a spacer on opposite sides of the sacrificial gate stack; and forming source/drain regions with the spacer as a mask.