1. A wafer grounding and biasing apparatus adaptable to a charged particle beam apparatus, comprising:
a wafer mount for supporting a wafer substrate;
a grounding pin arranged to be in contact with at least one backside film formed on a backside of the wafer substrate; and
a grounding pulse generator for providing at least one pulse to drive the grounding pin such that dielectric breakdown occurring at the backside films leads to establishment of a current path through the backside films;
wherein a pulse current flows in the wafer substrate through the current path and then flows out of the wafer substrate via at least one current return path formed from capacitive coupling between the wafer substrate and the wafer mount.
2. The apparatus of claim 1, wherein single one of the grounding pin is included in the apparatus.
3. The apparatus of claim 1, wherein the charged particle beam apparatus is an electron microscope.
4. The apparatus of claim 1, wherein the wafer mount is an electrostatic chuck.
5. The apparatus of claim 4, wherein the electrostatic chuck comprises at least one positive electrode and at least one negative electrode.
6. The apparatus of claim 5, further comprising an electrostatic chuck power supply for supplying positive voltage and negative voltage for the positive electrodes and the negative electrodes, respectively.
7. The apparatus of claim 6, wherein the electrostatic chuck power supply comprises a positive DC voltage source and a negative DC voltage source, wherein the at least one current return path includes a first current return path or a second current return path or both;
wherein the first current return path includes the capacitive coupling between the wafer substrate and the positive electrode, interconnection between the positive electrode and the positive DC voltage source, and the positive DC voltage source; and
wherein the second current return path includes the capacitive coupling between the wafer substrate and the negative electrode, interconnection between the negative electrode and the negative DC voltage source, and the negative DC voltage source.
8. The apparatus of claim 1, further comprising a resistor connected between the grounding pulse generator and the grounding pin.
9. The apparatus of claim 1, further comprising a wafer bias supply for controllably providing, during a wafer biasing operation, a predetermined potential to the wafer substrate via the grounding pin.
10. The apparatus of claim 1, wherein multiple ones of the grounding pin are included in the apparatus, wherein one of the multiple grounding pins is driven by the grounding pulse generator to trigger the dielectric breakdown at a time.
11. The apparatus of claim 10, further comprising a switch that selects one of the multiple grounding pins to be driven by the grounding pulse generator.
12. The apparatus of claim 1, further comprising a return-side grounding pin that is recessed back from contact with the backside films or is physically removed, wherein the return-side grounding pin is originally used for creating a current path through which a current can flow out of the water substrate.
13. A charged particle beam apparatus, comprising:
a charged particle beam generator for generating a charged particle beam to impinge on the surface of a wafer substrate;
an electron detector for detecting electrons from the surface of the wafer substrate being impinged;
an image generator electrically coupled to the electron detector for generating images of the substrate surface according to the electrons detected by the electron detector;
a wafer mount for supporting the wafer substrate;
a grounding pin arranged to be in contact with at least one backside film formed on a backside of the wafer substrate; and
a grounding pulse generator for providing at least one pulse to drive the grounding pin such that dielectric breakdown occurring at the backside films leads to establishment of a current path through the backside films;
wherein a pulse current flows in the wafer substrate through the current path and then flows out of the wafer substrate via at least one current return path formed from capacitive coupling between the wafer substrate and the wafer mount.
14. The apparatus of claim 13, wherein single one of the grounding pin is included in the apparatus.
15. The apparatus of claim 13, wherein the wafer mount is an electrostatic chuck that comprises at least one positive electrode and at least one negative electrode.
16. The apparatus of claim 15, further comprising an electrostatic chuck power supply for supplying positive voltage and negative voltage for the positive electrodes and the negative electrodes, respectively;
wherein the electrostatic chuck power supply comprises a positive DC voltage source and a negative DC voltage source, wherein the at least one current return path includes a first current return path or a second current return path or both;
wherein the first current return path includes the capacitive coupling between the wafer substrate and the positive electrode, interconnection between the positive electrode and the positive DC voltage source, and the positive DC voltage source; and
wherein the second current return path includes the capacitive coupling between the wafer substrate and the negative electrode, interconnection between the negative electrode and the negative DC voltage source, and the negative DC voltage source.
17. The apparatus of claim 13, wherein multiple ones of the grounding pin are included in the apparatus, wherein one of the multiple grounding pins is driven by the grounding pulse generator to trigger the dielectric breakdown at a time.
18. The apparatus of claim 13, further comprising a return-side grounding pin that is recessed back from contact with the backside films or is physically removed, wherein the return-side grounding pin is originally used for creating a current path through which a current can flow out of the water substrate.
19. A wafer grounding and biasing method adaptable to a charged particle beam apparatus, comprising:
supporting a wafer substrate with a wafer mount;
arranging a grounding pin to be in contact with a backside film formed on the backside of the wafer substrate;
providing at least one pulse to drive the grounding pin such that dielectric breakdown occurring at the backside films leads to establishment of a current path through the backside films; and
a pulse current flows in the wafer substrate through the current path and then flows out of the wafer substrate via at least one current return path formed from capacitive coupling between the wafer substrate and the wafer mount.
20. The method of claim 19, wherein single one of the grounding pin is included in the charged particle beam apparatus.
21. The method of claim 19, wherein the wafer mount is an electrostatic chuck that comprises at least one positive electrode and at least one negative electrode.
22. The method of claim 21, further comprising a step of supplying positive voltage and negative voltage for the positive electrodes and the negative electrodes, respectively, wherein individual of the positive and negative electrodes constitute the capacitive coupling with the wafer substrate.
23. The method of claim 19, further comprising a step of controllably providing, during a wafer biasing operation, a predetermined potential to the wafer substrate via the grounding pin.
24. The method of claim 19, wherein multiple ones of the grounding pin are included in the charged particle beam apparatus, wherein one of the multiple grounding pins is driven to trigger the dielectric breakdown at a time.
25. The method of claim 19, further comprising a step of removing a return-side grounding pin by recessing back the return-side grounding pin back from contact with the backside films or physically removing the return-side grounding pin, wherein the return-side grounding pin is originally used for creating a current path through which a current can flow out of the water substrate.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. Device for determining the corrosion of the grinding bodies in a rotary mill comprising a cylindrical shell ring (10) revolving about its longitudinal axis and containing a grinding charge comprising grinding bodies made of metal alloy, the mill having the material that is to be milled pass longitudinally through it, characterized in that at least one grinding body (30) identical to those that make up the grinding charge is fixed to an elastomer or rubber pedestal (28), itself fixed to the interior surface of the shell ring, and in that this grinding body (30) is exposed to the conditions inside the mill and is associated with a reference electrode (36) from which it is electrically insulated, in that the said reference electrode (36) is protected from impact knocks of the charge in the mill that is in electrical contact with the pulp in the mill and in that the said grinding body (30) and the said electrode (36) are electrically connected to a measurement apparatus (18) fixed outside the shell ring of the mill.
2. Device according to claim 1, characterized in that the said pedestal (28) comprises several pairs of grinding bodies (30) and reference electrodes (36), at least one grinding body of which is identical to those that make up the charge.
3. Device according to claim 1, characterized in that each grinding body (30) is fixed to the pedestal (28) and to the shell ring using a hollow bolt (32) passing radially through the pedestal (28) and the shell ring and containing the reference electrode (36).
4. Device according to claim 3, characterized in that the reference electrode (36) is bathed in an electrolyte contained in an axial bore (34) of the bolt (32), the said electrolyte being in electrical contact with the pulp in the mill.
5. Device according to claim 4, characterized in that the axial bore (34) in the bolt (32) is closed, at the interior end, by a spongy plug (40) protecting the reference electrode (36) from knocks and allowing contact with the pulp.
6. Device according to claim 1, characterized in that the pedestal (28) carrying the grinding bodies (30) and the reference electrodes (36) is fixed on the inside of the inspection hatch (14), each mill being equipped with at least one of these hatches.
7. Device according to claim 2, characterized in that the pedestal (28) carrying the grinding bodies (30) and the reference electrodes (36) is fixed on the inside of the inspection hatch (14), each mill being equipped with at least one of these hatches.
8. Device according to claim 3, characterized in that the pedestal (28) carrying the grinding bodies (30) and the reference electrodes (36) is fixed on the inside of the inspection hatch (14), each mill being equipped with at least one of these hatches.
9. Device according to claim 4, characterized in that the pedestal (28) carrying the grinding bodies (30) and the reference electrodes (36) is fixed on the inside of the inspection hatch (14), each mill being equipped with at least one of these hatches.
10. Device according to claim 5, characterized in that the pedestal (28) carrying the grinding bodies (30) and the reference electrodes (36) is fixed on the inside of the inspection hatch (14), each mill being equipped with at least one of these hatches.
11. Device according to claim 1, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
12. Device according to claim 2, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
13. Device according to claim 3, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
14. Device according to claim 4, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
15. Device according to claim 5, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
16. Device according to claim 6, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
17. Device according to claim 7, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
18. Device according to claim 8, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
19. Device according to claim 9, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
20. Device according to claim 10, characterized in that the said measurement apparatus (18) makes it possible to measure potential and current on each grinding body (30) and its reference electrode (36) and sends the data, telematically, to a receiving module (24) remote from the mill.
21. Device according to claim 11, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
22. Device according to claim 12, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
23. Device according to claim 13, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
24. Device according to claim 14, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
25. Device according to claim 15, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
26. Device according to claim 16, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
27. Device according to claim 17, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
28. Device according to claim 18, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
29. Device according to claim 19, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).
30. Device according to claim 20, characterized in that the results of the potential andor current measurements are analysed and correlated with known measurement results so as to provide information regarding the state of corrosion of each ball (30).