Oxide Semiconductor Storage Circuit for Nonvolatile Reconfigurable Logic

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Solution Overview

Problem

Semiconductor devices face challenges in maintaining the connection relation between logic circuit units or circuit configuration for a long time after power supply voltage is stopped, and achieving high-speed operation with low power consumption.

Innovation Solution

A semiconductor device incorporating an oxide semiconductor in the storage circuit, which includes a transistor and a capacitor, allowing data to be stored and maintained even after power is off, and enabling fast reconfiguration and low power consumption by using a selector circuit to control the connection between logic circuit units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If flash memory is used as the storage circuit, then data can be maintained even after supply of power supply voltage is stopped, but it is difficult to achieve high-speed operation and reduce power consumption because the drive voltage of flash memory is high

Engineering Contradiction:

Improvedata retention timeVSAvoidpower consumption

Core Design Contradiction:

Duration of action of stationary objectVSUse of energy by moving object

Solution Approach 1:

The storage circuit is divided into two distinct parts: a volatile storage element (SRAM/DRAM) for fast data access and a nonvolatile storage element (flash memory) for long-term data retention. This segmentation allows the system to leverage the advantages of both storage types while mitigating their individual disadvantages, achieving both high-speed operation and low power consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Data is pre-loaded into the volatile storage element before power is stopped. When power is restored, the system quickly retrieves this pre-loaded data from the volatile storage, avoiding the need to read from the slower flash memory, thus achieving high-speed operation with reduced power consumption.

Inventive Principle:

Principle #10Preliminary action

2Speed

If SRAM or DRAM is used as the storage circuit, then the connection relation between ALUs or the circuit configuration of each ALU can be changed at high speed, but stored data is lost when supply of power supply voltage is stopped

Engineering Contradiction:

Improvereconfiguration speedVSAvoiddata retention time

Core Design Contradiction:

SpeedVSDuration of action of stationary object

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Data is copied from the volatile storage element to the nonvolatile storage element before power is stopped. This creates a backup copy that persists after power loss, while the volatile storage retains the original data for fast access when power is restored, enabling both high-speed reconfiguration and data retention.

Inventive Principle:

Principle #26Copying

3Productivity

If a conventional transistor is used in the storage circuit, then the device can operate at standard speeds, but leakage current is high and data retention after power-off is poor

Engineering Contradiction:

Improveoperation speedVSAvoidleakage current

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The transistor channel is constructed using an oxide semiconductor material, which combines the beneficial properties of semiconductors (high mobility when conducting) with extremely low leakage current when non-conducting. This composite material approach enables the transistor to maintain low leakage current even during standby or after power-off, while still supporting high-speed operation when active.

Inventive Principle:

Principle #40Composite materials

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 semiconductor device effectively maintains data and circuit configuration for an extended period without power, enabling high-speed operation and reduced power consumption by leveraging the low leakage current of oxide semiconductors and efficient data storage.

Implementation Method 1

leveraging the low leakage current of oxide semiconductors

Methodology Applied

Scientific EffectLow leakage current property of oxide semiconductors:

Implementation Method 2

which includes a transistor and a capacitor, allowing data to be stored and maintained

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10505547B2Semiconductor device

Publication Date: 2019.12.10 SEMICON ENERGY LAB CO LTD

AI summary

An object is to provide a semiconductor device that can maintain the connection relation between logic circuit units or the circuit configuration of each of the logic circuit units even after supply of power supply voltage is stopped. Another object is to provide a semiconductor device in which the connection relation between logic circuit units or the circuit configuration of each of the logic circuit units can be changed at high speed. In a reconfigurable circuit, an oxide semiconductor is used for a semiconductor element that stores data on the circuit configuration, connection relation, or the like. Specifically, the oxide semiconductor is used for a channel formation region of the semiconductor element.