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Charge weight
Check if the weight of poly silicon is accurate before charging it to the grower.
Dopant weight
Check if the amount of the dopant, which gives the electrical characteristics intended by the manufacturing specification, is accurate.
Growth parameter
Make sure that the parameters loaded into the growing program of the crystal grower, which grows single crystals, match those of the registered program.
Crystal Length
Of the grown crystal, measure the length of the body that can be used for wafer production.
Crystal diameter
Measure the diameter of a grown crystal.
Slug thickness
Check if the thickness of the slug, tested for quality evaluation, lies within the specified thickness range.
Resistivity / RRG
Measure the resistivity and RRG values of the crystal.
Oi / ORG
Measure the concentration and ORG of the interstitial oxygen contained in the crystal.
After thermal treatment of the crystal under a certain condition, visually inspect the crystal for defects formed during the crystal growing process.
After the etching process under a certain condition, check if any dislocation happened during the crystal growing process.
Flat depth
Measure and check if the depth of the flat formed during the grinding process is proper.
Flat orientation
The crystal is flat processed to mark the wafer's orientation so that cutting of the chip is facilitated using the single crystal's orientation. Check if the formed flat's orientation is correct.
Notch depth
To improve a device's yield, a V-shaped groove is formed on the crystal, where the groove, called "notch," plays the same role as the flat. Check the depth of the notch.
Ingot orientation
Check if the orientation of a single crystal is <100> or <111>.
(X,Y) Diameter
Measure the X diameter (diameter of the wafer) and Y diameter (diameter of the wafer's flat area).
Measure the wafer's thickness.
Measure the concave or convex deformity of the median surface from the wafer's mid point. (The bow is defined as the deviation of the center point of the median surface of a free, unclamped wafer from a median-surface reference plane established by three points equally spaced on a circle with diameter a specified amount less than the nominal diameter of the wafer.)
Measure the maximum and minimum deviations of a wafer's median surface with respect to a reference plane, and compute the difference of the two.
Measure the maximum and the minimum thicknesses of a wafer, and compute the difference of the two.
Visual Inspection
Inspect a wafer's surface and edge with naked eyes for contamination and scratches.
Making depth & diameter
Measure the depth and the diameter of a marking.
Thickness removal
Measure the thickness portion of the wafer that has to be eliminated during etching to get rid of mechanical damages.
Backside brightness
Measure the brightness of a wafer's backside that did not undergo processes such as polishing and cleaning.
Use the Lifetime method to measure the degree of contamination due to metallic impurities during the growing and the wafering processes.
After cleaning, inspect a finished wafer's surface by searching for minute quantity of solid or liquid matters, called particles, using different size categories.
Inspect a wafer's surface for scratches, which are formed, for instance, when wafers collide with one another, the vacuum arm, or the surface plate during the lapping process.
Metallic Impurity
Measure the degree of contamination due to chemical-based metallic impurities during the wafering processes.