The only solution is to perform on-chip serial measurement.
In that way measurement is non sensitive to parasitic capacitors (like in
SC electronic circuits)

At 17:16 01/12/98 +0800, you wrote:
>hi there! i encountering the same problem. how do detect such small
>capacitance of 1fF?
>
>----------
>> From: Chieh-Hsiao Wang 
>> To: [email protected]
>> Subject: capacitive sensor measurement
>> Date: Thursday, November 19, 1998 3:31 AM
>>
>> Dear Colleague:
>>
>>      Capacitor in MEMS is usually very small (~ fF).
>>      How can I measure the capacitance of this kind of capacitor at the
>>         presence of large parasitic capacitor and resistor?
>>
>> ---
>> Chieh-Hsiao Wang
>> [email protected]
>> Department of ECpE
>> Iowa State University
>>
>
>