Semiconductor Annealing with Thermal Radiation Melting-Depth Estimation

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Solution Overview

Problem

The distribution of impurity activation rates in semiconductor wafers during annealing depends on the melting depth, making it essential to determine the melting depth for assessing the quality of the annealing process.

Innovation Solution

An annealing device and method that utilize a heating unit to melt the outer layer of a semiconductor wafer, a sensor to detect thermal radiation, and a processing unit to estimate the melting depth based on the temporal change in thermal radiation light intensity, with peaks indicating the start of melting and complete solidification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser annealing is performed to activate dopant ions implanted into the deep region, then the activation annealing of the dopant is achieved, but the melting depth at the time of annealing cannot be determined

Engineering Contradiction:
Improveactivation annealing qualityVSAvoidmelting depth measurement
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent uses thermal radiation light detection to provide real-time feedback on the melting depth during laser annealing. The sensor detects thermal radiation from the heated region, and the processing unit analyzes the waveform to determine melting depth, enabling closed-loop control and quality assessment of the annealing process

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces direct physical measurement methods with optical detection. Instead of using mechanical or contact-based measurement techniques to determine melting depth, the system uses non-contact thermal radiation light detection to estimate the melting depth based on the temporal characteristics of the emitted light

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If the melting depth is not known, then the quality assessment of the annealing process is impaired, but additional measurement devices increase device complexity

Engineering Contradiction:
Improveannealing process qualityVSAvoidmeasurement system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The sensor serves multiple functions: it detects thermal radiation light for temperature monitoring, provides waveform data for melting depth estimation, and enables quality assessment of the annealing process. This multi-functionality eliminates the need for separate measurement devices, reducing overall system complexity while maintaining manufacturing precision

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The annealing object itself serves as the measurement source. The thermal radiation light emitted by the heated region during annealing provides the necessary information for melting depth determination, eliminating the need for external measurement systems and reducing device complexity

Inventive Principle:
Principle #25Self-service

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 accurate estimation of the melting depth by analyzing the melting time from the thermal radiation light waveform, allowing for improved assessment of the annealing process without additional measurements.

Implementation Method 1

a heating unit that heats a surface of an annealing object to temporarily melt an outer layer portion

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a sensor that detects thermal radiation light from the annealing object heated by the heating unit

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

heats a surface of an annealing object to temporarily melt an outer layer portion

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 4

the waveform includes a peak corresponding to a start of melting and a peak corresponding to complete solidification

Methodology Applied
Scientific EffectSolidification: Freezing

Data Source

PatentEP3893269B1Annealing device and annealing method
Publication Date: 2023.11.01 SUMITOMO HEAVY IND LTD
  • EP3893269B1 patent drawingFigure 1
  • EP3893269B1 patent drawingFigure 2
  • EP3893269B1 patent drawingFigure 3

AI summary

A heating unit heats a surface of an annealing object to temporarily melt an outer layer portion. A sensor detects thermal radiation light from the annealing object heated by the heating unit. A processing unit estimates an annealing result of the annealing object on the basis of a waveform showing a temporal change in an intensity of the thermal radiation light detected by the sensor.