Wafer Support Pin Flat Rounded Front End Annealing

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Solution Overview

Problem

Conventional wafer support pins are insufficient for larger wafers, leading to increased gravitational stress and slip dislocation during high-temperature rapid thermal annealing, which can result in surface defects and reduced yield in semiconductor manufacturing.

Innovation Solution

A wafer support pin with a flat or rounded front end, made of quartz or monocrystalline/polycrystalline silicon, and optionally doped with N or C, and coated with SiC or Si3N4, to minimize gravitational stress and heat loss, with a controlled contact area to prevent slip dislocation, and an intermediate stabilization step during annealing to reduce thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the contact area between pin and wafer is minimized, then thermal stress is reduced, but gravitational stress concentration increases causing slip dislocation

Engineering Contradiction:

Improveheat lossVSAvoidslip control

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The support pin geometry is optimized with a flat or rounded front end to increase contact area for gravitational load distribution, while maintaining minimal overall contact to reduce heat loss during rapid thermal annealing. This local differentiation resolves the contradiction between heat loss and slip control.

Inventive Principle:

Principle #3Local quality

2Productivity

If high temperature rapid thermal annealing is used to form denuded zone and BMD, then productivity increases due to short process time, but slip dislocation occurs on wafer surface

Engineering Contradiction:

Improveprocess timeVSAvoidsurface quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The support pin is pre-designed with a flat or rounded front end geometry that distributes gravitational stress before the rapid thermal annealing process begins. This preliminary structural preparation prevents slip dislocation during the high-temperature process, maintaining surface quality while achieving high productivity.

Inventive Principle:

Principle #10Preliminary action

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 solution effectively reduces gravitational stress and thermal stress, achieving a slip-free wafer surface and improving the quality of annealed wafers by distributing load and reducing thermal expansion mismatch, while maintaining productivity.

Implementation Method 1

a front end of the wafer support pin, contacted with the wafer, is flat or rounded to minimize gravitational stress during annealing the wafer

Methodology Applied

Scientific EffectGravitational stress: Gravitation

Implementation Method 2

minimize thermal stress caused by heat loss and deviation of thermal expansion coefficient according to the material difference of silicon and quartz

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

minimize heat loss

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 4

an annealing process is generally carried during a semiconductor device manufacturing procedure

Methodology Applied

Scientific EffectAnnealing: Annealing

Implementation Method 5

the rapid thermal annealing process employs a method of balancing the center of gravity of a wafer on a 0.7 R inner 3-point support points

Methodology Applied

Scientific EffectThermal stress: Thermal Expansion

Data Source

PatentUS7767596B2Wafer support pin for preventing slip dislocation during annealing of water and wafer annealing method using the same

Publication Date: 2010.08.03 LG SILTRON

AI summary

A wafer support pin has a front end contacted with a wafer such that the front end is flat or rounded. Thus, gravitational stress is minimized during annealing the wafer, thereby minimizing slip dislocation. This wafer support pin is suitably used for annealing of a wafer, particularly high temperature rapid thermal annealing of a large-diameter wafer.