SIO probe for real-time monitoring and control of oxygen during czochralski growth of single crystal silicon

A method for determining the amount of oxygen in a pool of molten silicon, the method comprising

• withdrawing a sample containing SiO from an atmosphere over the molten silicon,
• reacting SiO present in the sample with a reactant to form a detectable reaction product,
• determining the amount of reaction product formed, and
• correlating the determined amount of reaction product to the amount of oxygen in the pool of molten silicon.

A method for determining, in near real-time, the oxygen content in a single crystal silicon ingot being drawn from a pool of molten silicon, the method comprising

• withdrawing a sample containing SiO from an atmosphere over the pool of molten silicon,
• reacting SiO present in the sample with a reactant to form a detectable reaction product,
• determining the amount of reaction product formed, and
• correlating the determined amount of reaction product to the oxygen content in the single crystal silicon ingot.

A method for controlling, in near real-time, the oxygen content in a single crystal silicon ingot being drawn from a pool of molten silicon under a set of process conditions that affect the oxygen content in the ingot, the method comprising

• withdrawing a sample containing SiO from an atmosphere over the pool of molten silicon,
• reacting SiO present in the sample with a reactant to form a detectable reaction product,
• determining the amount of reaction product formed, and
• effecting a change in at least one process condition that affects the oxygen content in the silicon ingot, the sense and magnitude of the change being based on the determined amount of reaction product.

A system for use in determining or controlling, in near-real time, the amount of SiO present in an atmosphere over a pool of molten silicon contained within a quartz crucible, the amount of oxygen in the molten silicon or the oxygen content of a single crystal silicon ingot drawn from the molten silicon according to the Czochraski method, the system comprising

• a SiO reaction probe located within a Czochraski crystal puller in the atmosphere over the pool of molten silicon for reacting SiO present in a gas sample withdrawn from the atmosphere with a reactant to form a detectable reaction product, the probe comprising a reaction chamber defined in a body of the probe, the probe body being made of a material having a melting point greater than about 1500.degree. C. and being non-contaminating to the molten silicon, an inlet port in fluid communication with the chamber and adapted for fluid communication with the atmosphere for withdrawing a sample containing SiO from the atmosphere into the chamber, an outlet port in fluid communication with the chamber and adapted for fluid communication with a detector for determining the amount of reaction product formed, and a reactant material contained within the chamber, the reactant material being capable of reacting with SiO present in the sample drawn into the chamber through the inlet port to form a detectable reaction product, and
• a detector for determining the amount of reaction product formed.

A method for determining, in near real-time, the oxygen content in a single crystal silicon ingot being drawn from a pool of molten silicon, the method comprising

• withdrawing a sample containing SiO from an atmosphere over the pool of molten silicon,
• reacting SiO present in the sample with graphite to form gaseous carbon monoxide and SiC,
• determining the amount of carbon monoxide formed, and
• correlating the determined amount of carbon monoxide to the oxygen content in the single crystal silicon ingot.