Semiconductor Floating Gate Data Retention via Ion Repulsion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional one-time programming (OTP) memory experiences poor data retention after a high-temperature baking process due to ions recombining with electrons stored in the floating gate, leading to reduced data retention.
Innovation Solution
A method involving a semiconductor device processing flow that includes a first voltage application to generate electrons, a baking process to reduce Si—H bonds, and a second voltage application to store additional electrons, followed by another baking process to maintain electron retention, thereby reducing hydrogenated complexes and improving data retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high-temperature baking process is applied to OTP memory, then data retention deteriorates due to ion recombination with electrons in the floating gate, but the device requires thermal processing for manufacturing
Solution Approach 1:
The patent applies a preliminary baking process before the final high-temperature baking to pre-release hydrogenated complexes and reduce the concentration of ions that would otherwise recombine with electrons during subsequent high-temperature processing. This preliminary action mitigates the harmful recombination effect while allowing necessary thermal processing to proceed
Solution Approach 2:
The patent applies a negative voltage to the floating gate before high-temperature baking to create an electric field that repels positively charged ions, preventing them from reaching and recombining with electrons in the floating gate. This preliminary anti-action directly counteracts the harmful recombination mechanism
2Duration of action of stationary object
If electrons are stored in the floating gate for data retention, then data can be maintained, but ions from the dielectric layer recombine with these electrons at high temperature, reducing retention time
Solution Approach 1:
The patent performs a preliminary baking process before final data programming to pre-release hydrogenated complexes from the dielectric layer. This reduces the pool of ions available for future recombination, thereby extending electron retention time during subsequent high-temperature storage
Solution Approach 2:
The patent introduces a control gate as an intermediary element that can apply electric fields to influence ion movement. By controlling the potential distribution, the control gate acts as a mediator to prevent ions from reaching the floating gate electrons, thereby protecting stored data
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 method effectively enhances data retention in OTP memory by minimizing the recombination of electrons with hydrogenated complexes, allowing data to be maintained for a longer period at elevated temperatures compared to conventional approaches.
Implementation Method 1
ions with positive charges released from an interface between a dielectric layer and a substrate of the one-time programming (OTP) memory recombine with electrons stored in a floating gate
Implementation Method 2
At high temperature, ions with positive charges released from an interface between a dielectric layer and a substrate
Data Source
AI summary
A semiconductor device includes a substrate, a dielectric layer and a floating gate. The dielectric layer disposed on the substrate. The floating gate disposed on the dielectric layer. After a first programming process, the floating gate is configured to store first electrons that are to be combined with ions from the dielectric layer. After a second programming process, the floating gate is configured to store second electrons, and a number of the second electrons is larger than a number of the first electrons.