In-situ real-time sheet resistance measurement system and method using an electrostatic chuck
AssigneeTexas Instruments Incorporated
InventorMehrdad M. Moslehi
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Abstract
A system 20 for measuring the sheet resistance of a conductive layer on the top surface of a semiconductor wafer 22 is disclosed herein. In one embodiment, the system includes a chuck 30 electrically coupled to the backside surface of the wafer 22. The chuck 30 is capable of supporting the wafer 22 electrostatically. A signal source 40 provides an excitation signal to the wafer 22 and circuitry for monitoring an induced signal is provided. The sheet resistance on the top surface of the wafer 22 is determined from the measurements of the excitation and induced electrical signals. Other systems and methods are also disclosed.
Claims21
A system for measuring output signals at selected locations on the top surface of a semiconductor wafer comprising:
- a chuck electrically coupled to the bottom surface of said wafer, said chuck capable of supporting said wafer electrostatically;
- a plurality of sensor electrodes attached to a surface of said chuck, said electrodes insulated from each other and from said chuck and said sensor electrodes electrically coupled to said bottom surface of said wafer, and wherein no sensor electrode is coupled to the frontside of said semiconductor wafer;
- a signal source coupled to at least one of said sensor electrodes to provide an excitation signal to said wafer and to induce signals in said wafer;
- and
- circuitry coupled to at least one other of said sensor electrodes for monitoring said induced signals.
Dependencies are inferred from the claim text.