Temperature control method of epitaxial growth apparatus

{
  "publication_number": "US7833348B2",
  "country": "US",
  "kind": "B2",
  "title": "Temperature control method of epitaxial growth apparatus",
  "abstract": "An object of the invention is to calibrate an upper pyrometer for indirectly measuring a substrate temperature at the time of epitaxial growth in a comparatively short time and with accuracy to thereby improve the quality of an epitaxial substrate. After calibrating an upper pyrometer by a thermocouple mounted to a temperature calibrating susceptor, a measured value of a lower pyrometer is adjusted to a calibrated value of the upper pyrometer. Then, a correlation line between substrate temperature indirectly measured by the upper pyrometer at the time of epitaxial growth onto a sample substrate and haze of a sample substrate measured immediately after epitaxial growth is set to indirectly measure a substrate temperature by the upper pyrometer at the time of epitaxial growth onto a mass-production substrate. Moreover, substrate temperature at the time of epitaxial growth onto the mass-production substrate is estimated by applying the haze of the mass-production substrate measured immediately after epitaxial growth to the correlation line and then a measured temperature of the upper pyrometer is adjusted to the estimated temperature.",
  "claims": [
    "1. A method for controlling the temperature of an epitaxial growth apparatus having an upper pyrometer above a mass-production susceptor and a lower pyrometer below the mass-production susceptor to grow an epitaxial layer on a mass-production substrate mounted onto the susceptor based on the temperature readings of both the upper and lower pyrometers, comprising: performing a first calibration for calibrating the upper pyrometer by a thermocouple mounted to a temperature calibrating susceptor previously set in place of the mass-production susceptor; adjusting a measured value of the lower pyrometer to a calibrated value of the upper pyrometer; setting a correlation line between a temperature of a sample substrate indirectly measured by the upper pyrometer at the time of epitaxial growth onto the sample substrate previously mounted onto the mass-production susceptor instead of the mass-production substrate and haze of the sample substrate measured immediately after epitaxial growth; indirectly measuring a temperature (Tx) of the mass production substrate by the upper pyrometer at the time of epitaxial growth onto the mass-production substrate; estimating a temperature (Ty) of the mass production substrate at the time of epitaxial growth onto the mass-production substrate by applying the haze of the mass-production substrate measured immediately after the epitaxial growth to the correlation line; and performing a second calibration for adjusting the measured temperature (Tx) of the upper pyrometer to the estimated temperature (Ty) of the mass production substrate.",
    "2. The method according to claim 1 wherein each of the haze of the sample substrate and the haze of the mass-production substrate is measured immediately after epitaxial growth by using a laser surface inspection apparatus.",
    "3. The method according to claim 1, wherein the calibration for adjusting the temperature (Tx) of the mass-production substrate indirectly measured to the estimated temperature (Ty) of the mass-production substrate is carried out when the difference between the temperature (Tx) of the mass-production substrate at the time of epitaxial growth indirectly measured by the upper pyrometer and the temperature (Ty) of the mass-production substrate at the time of epitaxial growth estimated by applying the haze of the mass-production substrate to a correlation line becomes 5° C. or higher."
  ],
  "cpc": [
    "C30B 25/10",
    "C30B 25/16"
  ],
  "assignees": [
    "SUMCO CORP"
  ],
  "filing_date": "2006-09-21",
  "publication_date": "2010-11-16",
  "grant_date": "2010-11-16",
  "priority_date": "2005-09-21",
  "application_number": "US-53388906-A",
  "family_id": "37882795",
  "citations": [
    "JP2000269137A",
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  ]
}