Aligned FinFET Sidewall Channels for Compact IC Layout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional integrated circuit devices with FinFETs require increased layout area and complex lithography processes due to non-aligned fin rotations for different channel crystal orientations, leading to inefficiencies in PMOS and NMOS transistor placement.
Innovation Solution
Implementing a Manhattan layout with fins rotated at 0° and 90° instead of 45°, using a direct silicon bonded substrate with hybrid crystal orientations to align PMOS and NMOS FinFETs channels, simplifying photolithography and reducing substrate area requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-Manhattan layout with 45° fin rotations is used to accommodate different crystal orientations for PMOS and NMOS FinFETs, then preferred surface orientations are achieved, but layout area increases by approximately 25% and lithography complexity increases
Solution Approach 1:
The patent utilizes the third dimension (vertical fin structure) to achieve different crystal orientations for PMOS and NMOS channels. By forming fins with specific crystallographic orientations and using selective epitaxial growth to create offset fin structures, the invention provides (110) orientations for PMOS and (100) orientations for NMOS without requiring planar 45° rotations, thus maintaining compact Manhattan layout geometry.
Solution Approach 2:
The patent applies different crystal orientations locally to specific transistor types within the same integrated circuit. PMOS fins are formed with (110) crystal orientations while NMOS fins use (100) orientations, achieved through selective epitaxial growth on offset fins. This local differentiation optimizes hole mobility for PMOS and electron mobility for NMOS without affecting other circuit elements.
2Reliability
If non-Manhattan layout with 45° fin rotations is used to accommodate different crystal orientations for PMOS and NMOS FinFETs, then preferred surface orientations are achieved, but lithography complexity increases
Solution Approach 1:
The patent moves the orientation differentiation from the planar lithography domain to the vertical epitaxial growth domain. Instead of requiring complex 45° rotated lithography patterns, the invention uses selective epitaxial growth on offset fins to create the necessary crystal orientation differences, simplifying the lithography process to standard Manhattan-aligned patterns.
Solution Approach 2:
The patent introduces offset fins as an intermediary structure that enables different crystal orientations without requiring complex lithography. The offset fins serve as templates for selective epitaxial growth, allowing (110) and (100) orientations to be achieved through controlled material deposition rather than complex pattern alignment.
3Area of stationary object
If Manhattan layout with 0° and 90° fin rotations is used, then layout area is reduced by 25% and lithography is simplified, but achieving preferred crystal orientations for both PMOS and NMOS becomes more difficult
Solution Approach 1:
The patent performs preliminary formation of offset fins with specific geometries before the main transistor fabrication. These offset fins are pre-configured to serve as templates for selective epitaxial growth, ensuring that the correct crystal orientations are achieved during subsequent processing steps without requiring complex alignment operations.
Solution Approach 2:
The patent changes the physical and chemical parameters of the epitaxial growth process to achieve different crystal orientations. By controlling temperature, pressure, gas flow rates, and precursor ratios during selective epitaxial growth, the invention enables (110) orientations for PMOS and (100) orientations for NMOS on Manhattan-aligned fins.
Data Source
AI summary
An integrated circuit device that includes a plurality of multiple gate FinFETs (MuGFETs) is disclosed. Fins of different crystal orientations for PMOS and NMOS MuGFETs are formed through amorphization and crystal regrowth on a direct silicon bonded (DSB) hybrid orientation technology (HOT) substrate. PMOS MuGFET fins are formed with channels defined by fin sidewall surfaces having (110) crystal orientations. NMOS MuGFET fins are formed with channels defined by fin sidewall surfaces having (100) crystal orienations in a Manhattan layout with the sidewall channels of the different PMOS and NMOS MuGFETs aligned at 0° or 90° rotations.