Method for locating a wafer in the ingot of same
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorsJordi Veirman, Sébastien Dubois
Life of this patent
Estimating the term…
Abstract
A method for determining the original position of a wafer in an ingot made from semiconductor material comprises the following steps: measuring the interstitial oxygen concentration in an area of the wafer; measuring the concentration of thermal donors formed in said area of the wafer during a previous solidification of the ingot; determining the effective time of a thermal donor formation anneal undergone by the wafer when solidification of the ingot took place, from the thermal donor concentration and the interstitial oxygen concentration; and determining the original position of the wafer in the ingot from the effective time.
Claims9
A method for determining an original position of a wafer in an ingot made from semiconductor material, comprising the following steps:
- measuring an interstitial oxygen concentration in one area of the wafer;
- measuring a concentration of thermal donors formed in said area of the wafer during a previous solidification of the ingot;
- determining an effective time of a thermal donor formation anneal undergone by the wafer when solidification of the ingot took place from the thermal donor concentration and the interstitial oxygen concentration;
- and
- determining the original position of the wafer in the ingot from the effective time.
Dependencies are inferred from the claim text.