Capacitance monitoring using X-ray diffraction

A method comprising:

• forming a deep trench on a substrate;
• conducting a first X-ray diffraction measurement on the substrate, wherein a first X-ray diffraction peak is observed in the the first X-ray diffraction measurement;
• depositing a high-k dielectric material on the substrate and in the deep trench;
• conducting a second X-ray diffraction measurement on the substrate, wherein a second X-ray diffraction peak is observed in the second X-ray diffraction measurement;
• measuring a difference between a center of the first X-ray diffraction peak and a center of the second X-ray diffraction peak, wherein the difference between the center of the first X-ray diffraction peak and the center of the second X-ray diffraction peak comprises a delta peak shift;
• correlating, using a database, a plurality of previously measured delta peak shift and deep trench capacitance values to obtain a correlation curve, wherein a lower capacitance limit and an upper capacitance limit are set in the correlation curve based on the database;
• and
• comparing to the correlation curve the delta peak shift to determine a deep trench capacitance value, wherein continuing processing of the substrate depends on the deep trench capacitance value being above the lower capacitance limit and below the upper capacitance limit set in the correlation curve.

A computer program product comprising:

• a computer readable non-transitory article of manufacture tangibly embodying computer readable instructions which, when executed, cause a computer to carry out a method comprising:
• conducting a first X-ray diffraction measurement on a substrate before forming a deep trench in the substrate, wherein a first X-ray diffraction peak is observed in the first X-ray diffraction measurement;
• conducting a second X-ray diffraction measurement on the substrate after depositing a high-k dielectric material in the deep trench, wherein a second X-ray diffraction peak is observed in the second X-ray diffraction measurement;
• measuring a difference between a center of the first X-ray diffraction peak and a center of the second X-ray diffraction peak, wherein the difference between the center of the first X-ray diffraction peak and the center of the second X-ray diffraction peak comprises a delta peak shift;
• correlating, using a database, a plurality of previously measured delta peak shift and deep trench capacitance values to obtain a correlation curve, wherein a lower capacitance limit and an upper capacitance limit are set in the correlation curve based on the database;
• and
• comparing to the correlation curve the delta peak shift to determine a deep trench capacitance value, wherein continuing processing of the substrate depends on the deep trench capacitance value being above the lower capacitance limit and below the upper capacitance limit set in the correlation curve.