Patent ID: 7026837

Claim:
A method of determining a permittivity of a dielectric layer of a semiconductor wafer comprising: (a) providing a means for contacting a topside of a semiconductor wafer, the contact means including at least a partially spherical surface formed from a conductive material; (b) determining a thickness of a dielectric layer on the semiconductor wafer having semiconducting material underlying the dielectric layer; (c) causing the at least partially spherical surface of the contact means to contact the topside of the semiconductor wafer thereby defining a capacitor, wherein the capacitance of the capacitor is comprised of a first capacitance resulting from materials in alignment with a contact area of the contact means in contact with the top surface of the semiconductor wafer and a second capacitance resulting from materials in alignment with a gap defined between the top surface of the semiconductor wafer and a surface of the contact means not in contact with the top surface surrounding the contact area; (d) applying an electrical stimulus to the contact means and the semiconducting material when the capacitor is defined; (e) determining the capacitance of the capacitor from the response thereof to the applied electrical stimulus; and (f) determining a permittivity of the dielectric layer as a function of the capacitance determined in step (e), the thickness of the dielectric layer determined in step (b) and the thickness of the gap surrounding the contact area.