Method, apparatus, and system for wafer grounding
Systems and methods for wafer grounding and wafer grounding location adjustment are disclosed. A first method may include receiving a first value of an electric characteristic associated with the wafer being grounded by an electric signal; determining a first control parameter using at least the first value; and controlling a characteristic of the electric signal using the first control parameter and the first value. A second method for adjusting a grounding location for a wafer may include terminating an electric connection between the wafer and at least one grounding pin in contact the wafer; adjusting a relative position between the wafer and the grounding pin; and restoring the electric connection between the grounding pin and the wafer. A third method may include causing a grounding pin to penetrate through a coating on the wafer by impact; and establishing an electrical connection between the grounding pin and the wafer.
1 . A method for grounding a wafer, the method comprising:
receiving a first value of an electric characteristic associated with the wafer being grounded by an electric signal;
determining a first control parameter based on a comparison of the first value and a target value of the electric characteristic; and
controlling a characteristic of the electric signal using the first control parameter and the first value.
2 . The method of claim 1 , wherein the electric characteristic is associated with an electric path comprising the wafer and a wafer mount supporting the wafer.
3 . The method of claim 2 , further comprising:
based on a determination that a resistance of the electric path is greater than or equal to a predetermined threshold value, determining a second control parameter using at least the first value, wherein the second control parameter and the first control parameter have different values; and
controlling the characteristic of the electric signal using the second control parameter and the first value.
4 . The method of claim 1 , wherein determining the first control parameter comprises:
determining whether a difference between the first value and the target value satisfies a threshold condition; and
determining the first control parameter based on a determination that the difference satisfies the threshold condition.
5 . A method for grounding a wafer, the method comprising:
receiving a first value of an electric characteristic associated with the wafer being grounded by an electric signal;
determining a first control parameter using at least the first value;
controlling a characteristic of the electric signal using the first control parameter and the first value; and
wherein the electric characteristic comprises at least one of an impedance, a resistance, a capacitive reactance, an admittance, a conductance, or a capacitive susceptance.
6 . The method of claim 5 , wherein the electric characteristic comprises one of a resistance between the wafer and a wafer mount or a capacitive reactance between the wafer and the wafer mount.
7 . The method of claim 1 , wherein a threshold condition comprises the first value being smaller than or equal to a target value.
8 . The method of claim 1 , wherein determining the first control parameter comprises:
determining an initial parameter using at least the first value; and
determining the first control parameter based on at least the initial parameter, the first value, the target value, and a type of the wafer.
9 . The method of claim 1 , wherein the characteristic of the electric signal comprises at least one of a voltage, a current, a profile of the voltage or the current, a frequency of the profile, a period of the profile, a phase of the profile, an amplitude of the profile, or a duration of the voltage or the current.
10 . The method of claim 1 , wherein controlling the characteristic of the electric signal using the first control parameter and the first value comprises:
changing a value of the characteristic of the electric signal using the first control parameter and the first value.
11 . The method of claim 1 , wherein controlling the characteristic of the electric signal comprises:
lowering a voltage of the electric signal.
12 . The method of claim 1 , further comprising:
receiving a second value of the electric characteristic after controlling the characteristic of the electric signal using the first control parameter and the first value;
determining a third control parameter using at least the second value, wherein the third control parameter and the first control parameter have different values; and
controlling the characteristic of the electric signal using the third control parameter and the second value.
13 . A system for grounding a wafer, the system comprising:
a sensor configured to generate a first value of an electric characteristic associated with the wafer being grounded by an electric signal;
an electric signal generator configured to generate the electric signal; and
a controller including circuitry for receiving the first value of the electric characteristic, determining a first control parameter based on a comparison of the first value and a target value of the electric characteristic, and controlling a characteristic of the electric signal using the first control parameter and the first value.
14 . The system of claim 13 , further comprising:
a grounding pin, electrically connected between the electric signal generator and the wafer.