Semiconductor Soft Error Inspection via Laser and Electron Beam
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current soft error inspection methods, particularly the laser evaluation method, cannot determine the durability or endurance time of semiconductor devices against radiation-induced malfunctions, making it difficult to assess the long-term reliability of such devices.
Innovation Solution
A soft error inspection method and apparatus that uses a combination of laser and electron beam irradiation to evaluate the endurance time of semiconductor devices by measuring bit information changes under various irradiation conditions, generating an endurance time map to quantify the reliability of each area, allowing for optimized memory allocation and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a laser evaluation method is used to inspect soft errors, then the inspection can be performed with small-scale equipment and specific memory areas can be individually evaluated, but only the inverted position can be known and durability (endurance period) regarding the soft error cannot be known
Solution Approach 1:
The patent combines laser beam irradiation with electron beam irradiation in a single inspection system. The laser beam induces soft errors by radiating photons to specific memory areas, while the electron beam detects the resulting bit inversions. This merging of two different radiation methods allows the system to maintain the advantage of small-scale equipment while gaining the capability to measure durability through controlled electron beam irradiation at varying doses.
Solution Approach 2:
The patent changes the irradiation parameters by controlling the electron beam dose and using different laser beam conditions to induce soft errors. By varying the electron beam irradiation dose and measuring bit inversion rates at different doses, the system can determine the endurance period and durability of memory areas against soft errors, transforming the inspection from simple position detection to quantitative durability assessment.
2Ease of operation
If traditional soft error inspection methods are used, then the inspection process is simple, but the endurance time and reliability information cannot be determined
Solution Approach 1:
The patent implements a feedback mechanism where the inspection results (bit inversion data from electron beam detection) are fed back to calculate endurance time and create error occurrence frequency maps. The system measures bit inversions at different electron beam doses, uses this feedback data to determine durability characteristics, and generates comprehensive reliability information including endurance time maps and error frequency distributions for each memory area.
Solution Approach 2:
The patent performs preliminary soft error induction using laser beam irradiation before the actual durability measurement. By pre-inducing soft errors with controlled laser irradiation and then measuring the persistence and inversion rates with electron beam irradiation at various doses, the system prepares the memory areas in a known state that enables subsequent durability assessment without requiring complex external testing equipment.
3Manufacturing precision
If laser beam irradiation is used to induce soft errors, then specific memory areas can be targeted, but the error occurrence frequency and durability quantification cannot be achieved
Solution Approach 1:
The patent uses the electron beam as an intermediary between the laser-induced soft errors and the measurement system. The laser beam targets specific memory areas to induce soft errors with high spatial precision, the electron beam acts as an intermediary to detect and quantify the resulting bit inversions at controlled doses, and the measurement system processes this intermediary data to calculate error occurrence frequencies and durability metrics for the targeted memory areas.
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
Enables the determination of endurance time and error occurrence frequency maps, enabling the adjustment of memory operations to meet specifications and ensuring reliable performance by identifying and avoiding low-durability areas, thus improving the overall reliability of semiconductor devices.
Implementation Method 1
a laser beam is radiated to a semiconductor device for a predetermined time under a predetermined irradiation condition
Implementation Method 2
a so-called soft error occurs that is a malfunction due to radiation
Implementation Method 3
the semiconductor device is irradiated with a laser beam and also irradiated with an electron beam
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The above problem is solved by a soft error inspection method for a semiconductor device, the soft error inspection method including: irradiating and scanning a semiconductor device with a laser beam or an electron beam; and measuring and storing a time of bit inversion for each of areas irradiated with the laser beam or the electron beam of the semiconductor device.