Merged Source-Drain Regions via Self-Aligned Epitaxy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for forming merged source/drain regions in integrated circuit products face challenges in ensuring physical contact between inversely doped P-type and N-type regions, often resulting in misalignment and increased processing costs due to the use of dual ion implantation processes.
Innovation Solution
A method involving the formation of vertically oriented channel semiconductor structures, recess creation, and epitaxial growth of P-type and N-type doped semiconductor materials, where a single patterned masking layer is used to ensure self-aligned engagement of P-type and N-type doped regions within the merged source/drain region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If dual ion implantation processes are used to form merged source/drain regions, then P-type and N-type doped regions can be formed, but misalignment and edge placement errors occur reducing manufacturing precision
Solution Approach 1:
The single patterned masking layer serves itself by defining both the recess location and the alignment reference for subsequent epitaxial growth. The masking layer remains in place during the entire process, automatically ensuring that the P-type and N-type doped regions are formed in correct registration without requiring additional alignment steps or multiple masks.
Solution Approach 2:
The recess is pre-formed in the substrate between the vertically oriented channel semiconductor structures before doping. This preliminary action creates a physical template that guides the subsequent epitaxial growth of doped regions, ensuring they form in the correct positions with proper alignment from the start of the doping process.
2Quantity of substance
If dual patterned implant masks are used, then complete doping coverage can be achieved, but processing costs and complexity increase
Solution Approach 1:
The formation of P-type and N-type doped regions, which traditionally requires separate implantation steps with two different patterned masks, is merged into a single epitaxial growth process. The single patterned masking layer defines both regions, and the epitaxial growth simultaneously forms both P-type and N-type doped semiconductor materials in their respective locations within the recess, eliminating the need for dual masking and sequential implantation.
3Manufacturing precision
If epitaxial growth is used instead of ion implantation, then self-aligned engagement is achieved, but process time may increase
Solution Approach 1:
The epitaxial growth process continuously deposits and dopes semiconductor material in a single uninterrupted step, forming both P-type and N-type doped regions simultaneously. This continuous process eliminates the need for multiple discrete ion implantation steps, mask removals, and re-alignments, achieving self-aligned engagement while maintaining efficient processing throughput.
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 ensures accurate physical contact between inversely doped regions, improves product yields, and reduces processing costs by eliminating edge placement errors and the need for dual patterned implant masks.
Implementation Method 1
forming a P-type-doped semiconductor material in the recess... forming a substantially horizontally-oriented N-type-doped semiconductor material in the recess laterally adjacent the second substantially horizontally-oriented portion of the P-type-doped semiconductor material
Data Source
AI summary
A method of forming a merged source/drain region is disclosed that includes forming first and second VOCS structures above a semiconductor substrate, forming a recess in the substrate between the first and second VOCS structures and forming a P-type-doped semiconductor material in the recess. In this particular example, the method also includes removing a first substantially horizontally-oriented portion of the P-type-doped semiconductor material from within the recess while leaving a second substantially horizontally-oriented portion of the P-type-doped semiconductor material remaining in the recess and forming a substantially horizontally-oriented N-type-doped semiconductor material in the recess laterally adjacent the second substantially horizontally-oriented portion of the P-type-doped semiconductor material, wherein the substantially horizontally-oriented N-type-doped semiconductor material physically engages the second substantially horizontally-oriented portion of the P-type-doped semiconductor material along an interface within the merged source/drain region.