Post-plasma clean infrared image inspection for oxideless bonding and apparatus for effecting the same

A method of forming a bonded assembly, the method comprising:

• providing a wafer including a plurality of packaging substrates;
• performing a wafer plasma clean process on the wafer in a low-oxygen ambient having an oxygen partial pressure that is lower than 17 kPa;
• generating at least one wafer infrared image of a cleaned side of the wafer;
• measuring an average emissivity of at least one metallic region in the at least one wafer infrared image;
• and
• performing a subsequent processing step selected from a bonding step and an alternative processing step based on the measured average emissivity,
• wherein the bonding step is performed in response to determining that the measured average emissivity is less than a predetermined emissivity threshold value and bonds at least one semiconductor chip to a respective one of the packaging substrate in the wafer, and
• the alternative processing step is performed in response to determining that the measured average emissivity is greater than the predetermined emissivity threshold value, the alternative processing step being selected from an additional clean step and an additional inspection step.

A method of forming a bonded assembly, the method comprising:

• performing a wafer plasma clean process on a wafer including a plurality of packaging substrates in a low-oxygen ambient;
• generating at least one wafer infrared image of a cleaned side of the wafer;
• measuring an average emissivity of at least one metallic region in the at least one wafer infrared image;
• and
• performing a subsequent processing step selected from a bonding step and an alternative processing step based on the measured average emissivity,
• wherein the bonding step is performed in response to determining that the measured average emissivity is less than a predetermined emissivity threshold value and bonds at least one semiconductor chip to a respective one of the packaging substrates in the wafer, and
• the alternative processing step is performed in response to determining that the measured average emissivity is greater than the predetermined emissivity threshold value.