Substrate processing apparatus
A substrate processing apparatus includes: a chamber configured to perform a wet process and having an internal space, a chuck in the internal spaced and being configured for loading a semiconductor substrate thereon, a probe having an end above the chuck and including an electro-optical crystal and a reflective mirror on one surface of the electro-optical crystal, a measuring unit connected to the probe and configured to provide reference light to the probe, and to detect a polarization component of reflected light reflected from the one end of the probe by the reference light, and a controller configured to calculate an amount of electrostatic charge on a surface of the semiconductor substrate from the polarization component.
1. A substrate processing apparatus, comprising:
a chamber having an internal space configured for performance of a wet process therein;
a chuck in a lower region of the internal space;
a probe having one end above an upper portion of the chuck, and including an electro-optical crystal having an optical refractive index configured to change in proportion to a magnitude of an electric field applied at an upper portion of a semiconductor substrate loaded onto the chuck, and the probe further including a reflective mirror on one surface of the electro-optical crystal;
a measuring unit connected to the probe, the measuring unit being configured to provide reference light to the probe and to detect a polarization component of reflected light from the reference light that is reflected from the reflective mirror of the probe; and
a controller configured to calculate an amount of electrostatic charge on a surface of the semiconductor substrate from the polarization component detected by the measuring unit.
2. The substrate processing apparatus of claim 1 , wherein the probe further comprises a chemical resistant resin layer on a surface of the probe.
3. The substrate processing apparatus of claim 2 , wherein the chemical resistant resin layer comprises at least one of Perfluoroalkoxy (PFA), Polytetrafluoroethylene (PTEE), and Ethylene tetrafluoroethylene (ETFE).
4. The substrate processing apparatus of claim 1 , wherein the probe further comprises an optical cable connecting the electro-optical crystal and the measuring unit.
5. The substrate processing apparatus of claim 4 , wherein the optical cable comprises a plurality of polarization maintaining fibers,
and the electro-optical crystal includes a plurality of electro-optical crystals corresponding to respective ones of the plurality of polarization maintaining fibers.
6. The substrate processing apparatus of claim 5 , wherein at least a portion of the plurality of electro-optical crystals have different thicknesses.
7. The substrate processing apparatus of claim 1 , wherein the measuring unit further comprises,
a light source configured to provide the reference light;
a polarization beam splitter configured to split the reflected light; and
a photodetector at a rear end of the polarization beam splitter and configured to detect the polarization component.
8. The substrate processing apparatus of claim 7 , wherein the light source comprises a laser diode.
9. The substrate processing apparatus of claim 7 , wherein the polarization beam splitter is configured to split the polarization component and another component from the reflected light.
10. The substrate processing apparatus of claim 1 , wherein the chuck comprises a driving shaft configured to support the chuck; and
a driving unit configured to rotate the driving shaft.
11. The substrate processing apparatus of claim 1 , wherein the measuring unit and the controller are positioned outside the chamber.
12. The substrate processing apparatus of claim 1 , wherein the probe is attached to a nozzle configured to move vertically and horizontally on the upper portion of the semiconductor substrate.
13. A substrate processing apparatus, comprising:
a chamber having an internal space configured for performance of a wet process therein;
a chuck in a lower region of the internal space and configured to rotate a semiconductor substrate seated on an upper surface thereof;
a probe having an end above an upper portion of the chuck, and including an electro-optical crystal having an optical refractive index configured to change in proportion to a magnitude of an electric field applied to an upper portion of the semiconductor substrate, and a reflective mirror on a surface of the electro-optical crystal;
a measuring unit connected to the probe, the measuring unit being configured to provide a reference light to the probe, and to detect a polarization component of reflected light that is reflected from the reflective mirror of the probe;
a charge controller including a variable resistor connected between the chuck and a ground electrode of the chuck in series; and
a main controller configured to calculate an amount of electrostatic charge on a surface of the semiconductor substrate from the polarization component detected by the measuring unit, to compare the amount of electrostatic charge with a reference value, and to control the variable resistor of the charge controller so that the amount of electrostatic charge matches a reference value.
14. The substrate processing apparatus of claim 13 , wherein the main controller is configured to reduce a resistance value of the variable resistor when the amount of electrostatic charge is greater than the reference value, and
the main controller is configured to increase a resistance value of the variable resistor when the amount of electrostatic charge is lower than the reference value.
15. The substrate processing apparatus of claim 13 , further comprising
an ionizer in an upper portion of the chamber that is configured to emit ions to the internal space.
16. The substrate processing apparatus of claim 13 , wherein the chuck further comprises:
a plate;
a support pin on an upper surface of the plate that is configured to support the semiconductor substrate;
a gripper on an edge of the upper surface of the plate and configured to secure an edge of the semiconductor substrate in a fixed position; and
a ground path inside the plate and configured to connect the support pin and the gripper to the ground electrode.
17. The substrate processing apparatus of claim 13 , wherein the probe further comprises a chemical resistant resin layer on a surface of the probe.
18. The substrate processing apparatus of claim 17 , wherein the chemical resistant resin layer comprises at least one of Perfluoroalkoxy (PFA), Polytetrafluoroethylene (PTEE), and Ethylene tetrafluoroethylene (ETFE).
19. The substrate processing apparatus of claim 13 , wherein the probe further comprises an optical cable connecting the electro-optical crystal and the measuring unit.
20. The substrate processing apparatus of claim 19 , wherein the optical cable comprises a plurality of polarization maintaining fibers,
and the electro-optical crystal includes a plurality of electro-optical crystals corresponding to respective ones of the plurality of polarization maintaining fibers.