Automatic mercury probe for use with a semiconductor wafer

A method of measurement of a wafer comprising the steps of:

• a. supporting said wafer with a surface to be measured facing downward;
• b. orienting a probe head with a flat face upward with at least one probe passage defined through the probe head and opening on said face with said face disposed to make contact with the downward facing surface of said wafer during testing;
• c. advancing said probe head upward and bring said flat face into contact with said downward facing surface of said wafer;
• d. providing said at least one probe passage with mercury until a mercury contact is made with said downward facing surface of said wafer with said mercury in each of said at least one probe passages providing an electrically conductive probe to the surface of said wafer;
• e. interconnecting an electrical measurement device to said mercury in each of said probe passage;
• f. measuring selected electrical values from said wafer with said electrical measurement device via said mercury in each of said probe passages;
• g. recovering said mercury from each of said at least one probe passage;
• and
• h. retracting said probe head from said surface of said wafer.

A probe measurement system for a wafer mounted with the surface to be measured facing downward, said system comprising:

• a probe head with a flat face oriented upward with at least one probe passage defined through the probe head ending in an orifice on said face with said face disposed to make contact with the downward facing surface of said wafer during testing;
• a mercury supply system disposed to provide mercury to said at least one probe passage and to extend mercury to the opening on said face with a mercury contact made with the surface of the wafer from each of said at least one probe passage when the face of the probe head is in contact with the surface of the wafer;
• and
• a mercury recovery system to recapture the mercury from said at least one probe passage in said probe head after each probing of the wafer surface and delivers the recovered mercury to said mercury supply system.

A method of measurement of a wafer comprising the steps of:

• a. supporting said wafer with the surface to be measured facing downward;
• b. orienting a probe head with a flat face upward with at least one probe passage defined through the probe head and opening on said face with said face disposed to make contact with the downward facing surface of said wafer during testing;
• c. advancing said probe head of step b. upward and to bring said flat face into contact with said downward facing surface of said wafer;
• and
• d. following step c. providing said at least one probe passage with mercury until a mercury contact is made with said downward facing surface of said wafer with said mercury in each of said at least one probe passages providing an electrically conductive probe to the surface of said wafer;
• wherein step c. is performed with a piston coupled to said probe head to provide a regulated selected upward pressure of said flat face of said probe head on said surface of said wafer when activated and following step d. to return said probe head to a rest position when inactivated.