Transistor-Based Fuse Programming via Gate Oxide Breakdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing one-time programmable (OTP) fuses in semiconductor devices require high voltages for programming, generating excess heat and potentially damaging surrounding components, and necessitate additional fabrication processes, as well as a separate voltage supply that may not be available on the semiconductor device.
Innovation Solution
A transistor-based fuse structure is formed using the same semiconductor fabrication process as the device, allowing for programming with low-resistance/high-current and high-resistance/low-current states by applying specific voltage configurations to the source, gate, and drain, including grounding or floating the gate and applying programming voltages to achieve desired states without altering the fuse physically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicided polysilicon OTP fuses are used, then fuse programming capability is achieved, but high programming voltages are required which generate excess heat and may damage surrounding components
Solution Approach 1:
The patent changes the electrical parameters of the fuse structure by using a thin-oxide MOS transistor instead of silicided polysilicon. The thin gate oxide (50-200 nm) enables breakdown at lower voltages compared to traditional OTP fuses, reducing the programming voltage from typically >10V to lower levels that generate less heat and avoid damaging surrounding components.
Solution Approach 2:
The patent replaces the physical/breakdown mechanism of silicided polysilicon OTP fuses with an electrical field effect mechanism. Instead of relying on high-voltage breakdown of silicide material, the invention uses electric field-induced breakdown of the thin gate oxide in a MOS transistor, which can be controlled more precisely and generates less thermal damage.
2Reliability
If silicided polysilicon OTP fuses are used, then fuse functionality is achieved, but additional fabrication processes are required beyond standard device manufacturing
Solution Approach 1:
The patent merges the fuse structure with the standard MOS transistor fabrication process. The fuse is formed as a thin-oxide MOS transistor using the same process steps as the main device transistors, consolidating multiple functions into a unified fabrication flow that eliminates separate fuse manufacturing steps.
Solution Approach 2:
The thin-oxide MOS transistor structure serves dual purposes: it functions as both the main device transistor and the fuse element. This universal structure eliminates the need for specialized fuse fabrication processes, as the same transistor design can be used for both operational devices and programmable fuse elements.
3Reliability
If silicided polysilicon OTP fuses are used, then fuse programming is possible, but a separate voltage supply is needed that may not be available on the semiconductor device
Solution Approach 1:
The thin-oxide MOS transistor fuse structure can be programmed using the device's own supply voltages without requiring external high-voltage sources. The thin gate oxide enables breakdown and programming at voltages that are naturally available in the device operation, making the fuse self-programmable using existing power supplies.
4Ease of manufacture
If transistor-based fuse structure is used, then conventional fabrication processes are utilized, but precise voltage control is required to achieve desired fuse states
Solution Approach 1:
The patent utilizes changes in voltage parameters to control the fuse state. By applying specific voltage combinations to the gate, source, and drain terminals, the thin-oxide MOS transistor can be programmed into desired states (broken-down or intact) using precisely controlled voltage application sequences that leverage the thin oxide's electrical characteristics.
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 method allows for efficient programming of semiconductor fuses using existing fabrication processes and supply voltages, reducing the risk of heat damage and eliminating the need for additional fabrication steps, while enabling precise control of fuse states without requiring high programming voltages.
Implementation Method 1
applies a first set of program voltages to the first source, the first gate, and the first drain to cause breakdown of the first gate insulator layer such that current can flow from the first source to the first gate through the first gate insulator layer, and from the first gate to the first drain through the first gate insulator layer
Data Source
AI summary
A transistor-based fuse structure is realized in a semiconductor device having a semiconductor substrate, transistor devices formed on the semiconductor substrate, and the transistor-based fuse structure formed on the semiconductor substrate. The transistor-based fuse structure includes a plurality of transistor-based fuses, and the method begins by selecting, from the plurality of transistor-based fuses, a first target fuse to be programmed for operation in a low-resistance/high-current state, the first target fuse having a first source, a first gate, a first drain, and a first gate insulator layer between the first gate and the semiconductor substrate. The method applies a first set of program voltages to the first source, the first gate, and the first drain to cause breakdown of the first gate insulator layer such that current can flow from the first source to the first gate through the first gate insulator layer, and from the first gate to the first drain through the first gate insulator layer.