Thin-Oxide CMOS Schmitt Trigger for Mixed-Voltage I/O
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of thick oxide devices and thin oxide devices on the same die becomes increasingly difficult and costly, especially in advanced technologies like GAAFET and MBCFET, due to the need for extra masks and larger layout areas, including keep out zones, which complicates the fabrication process.
Innovation Solution
A Schmitt trigger circuit designed and manufactured using only thin oxide FET devices, which eliminates the need for integrating thick oxide devices and reduces costs by eliminating extra masks and keep out zones, while providing a layout and manufacturing-friendly solution for next-generation technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If thick oxide devices and thin oxide devices are integrated on the same die, then the demands of I/O circuits, ESD control circuits, and core logic circuits are fulfilled, but the fabrication process becomes increasingly difficult and costly due to extra masks and larger layout areas
Solution Approach 1:
The patent extracts the thick oxide device functionality from the mixed-oxide architecture and implements it using thin oxide devices with appropriate circuit configurations. This eliminates the need for separate thick oxide device fabrication processes while maintaining the required I/O circuit, ESD control, and core logic circuit functionalities.
Solution Approach 2:
The patent makes thin oxide devices perform multiple functions that previously required both thick oxide and thin oxide devices. By configuring thin oxide devices to handle I/O signals, ESD protection, and core logic operations, the design achieves multi-functionality with a single device type, simplifying the fabrication process.
2Adaptability or versatility
If thick oxide devices and thin oxide devices are integrated on the same die, then mixed voltage I/O interfaces are enabled, but layout area increases due to keep out zones between device types
Solution Approach 1:
The patent removes the requirement for keep out zones by eliminating thick oxide devices from the design. Thin oxide devices are configured to handle all voltage levels through appropriate circuit arrangements, extracting the voltage handling capability from the physical device structure to the circuit level.
Solution Approach 2:
The patent changes the operating parameters of thin oxide devices to handle higher voltages and different current conditions that previously required thick oxide devices. By adjusting bias conditions and circuit configurations, thin oxide devices achieve the same voltage interface capabilities with reduced layout area.
3Reliability
If thick oxide devices are used for I/O circuits operating at higher voltages, then device reliability is ensured, but manufacturing precision requirements increase due to process complexity
Solution Approach 1:
The patent uses homogeneous thin oxide device technology throughout the design, eliminating the heterogeneity of mixing thick and thin oxide processes. This uniformity simplifies the fabrication process and reduces precision requirements while maintaining reliability through proven thin oxide device performance and appropriate circuit design.
Data Source
AI summary
A device including an inverter circuit, a hysteresis control circuit, and a high-side input level shifter. The inverter circuit having an output and including at least two series connected PMOS transistors connected, at the output, in series to at least two series connected NMOS transistors. The hysteresis control circuit coupled to the output to provide feedback to the at least two series connected PMOS transistors and to the at least two series connected NMOS transistors. The high-side input level shifter connected to gates of the at least two PMOS transistors and configured to shift a low level of an input signal to a higher level and provide the higher level to one or more of the gates of the at least two PMOS transistors.