1. A chemical mechanical polishing (CMP) apparatus comprising:
a wafer;
a polishing pad to polish a surface of the wafer;
a polishing pad structure to rotate the polishing pad over the surface of the wafer; and
a wafer chuck to support the wafer, the wafer chuck being arranged to support a first portion of the wafer that is in physical contact with the wafer chuck and to indirectly support a second portion of the wafer that is not in physical contact with the wafer chuck, wherein the second portion of the wafer is supported by the wafer chuck using a bearing surface arranged between the second portion of the wafer and the wafer.
2. The CMP apparatus of claim 1 wherein the wafer chuck is arranged to support the first portion of the wafer using a vacuum pressure.
3. The CMP apparatus of claim 1 wherein the wafer chuck defines at least one opening, the CMP apparatus further including:
a first supply, the first supply being arranged to provide the wafer chuck with a supply through the at least one opening that is arranged to create a boundary layer between an edge surface of the wafer chuck and the second portion of the wafer, wherein the boundary layer forms the bearing surface.
4. The CMP apparatus of claim 3, wherein the first supply is an air supply, and the bearing surface is an air bearing surface.
5. The CMP apparatus of claim 3, wherein the first supply is a fluid supply, and the bearing surface is a fluid bearing surface.
6. The CMP apparatus of claim 1 wherein the second portion of the wafer is a bottom edge periphery of the wafer, and wherein a boundary layer is formed between the bottom edge periphery of the wafer and an outside edge surface of the wafer chuck.
7. The CMP apparatus of claim 6 wherein a distance between the bottom edge periphery of the wafer and the outside edge surface of the wafer chuck is approximately 10 micrometers.
8. The CMP apparatus of claim 1 wherein the bearing surface has an associated pressure, the associated pressure being arranged to support the second portion of the wafer.
9. The CMP apparatus of claim 8 wherein the associated pressure is adjustable to adjust an amount of support provided to the second portion of the wafer.
10. A method for controlling a removal rate of material from a top surface of a wafer during chemical mechanical polishing (CMP), the wafer being supported on a wafer chuck such that a portion of the wafer is in direct contact with the wafer chuck, the method comprising:
applying a polishing pressure to the top surface of the wafer; and
applying a support pressure to an edge periphery of a bottom surface of the wafer, wherein the support pressure is applied through a gap between an edge surface of the wafer chuck and the edge periphery of the bottom surface of the wafer, the edge periphery of the bottom surface of the wafer not being in direct contact with the wafer chuck.
11. A method for controlling a removal rate of material from a top surface of a wafer during chemical mechanical polishing (CMP) the wafer being supported on a wafer chuck the method comprising:
applying a polishing pressure to the top surface of the wafer; and
applying a support pressure to an edge periphery of a bottom surface of the wafer, wherein the support pressure is applied through a gap between an edge surface of the wafer chuck and the edge periphery of the bottom surface of the wafer, the edge periphery of the bottom surface of the wafer not being in direct contact with the wafer chuck wherein the support pressure is in the range of between approximately 0.3 Mega Pascal (MPa) and approximately 0.6 MPa.
12. The method of claim 10 wherein applying the support pressure to the edge periphery of the bottom surface of the wafer includes distributing an air pressure on the edge periphery of the bottom surface of the wafer, the air pressure being arranged to act as an air bearing in the gap.
13. The method of claim 10 wherein applying the support pressure to the edge periphery of the bottom surface of the wafer includes distributing a fluid pressure on the edge periphery of the bottom surface of the wafer, the fluid pressure being arranged to act as fluid bearing in the gap.
14. The method of claim 10 further including:
determining if the removal rate of material from the top surface of the wafer over the edge periphery is acceptable; and
adjusting the support pressure to the edge periphery of the bottom surface of the wafer if it is determined that the removal rate of material from the top surface of the wafer over the edge periphery is not acceptable.
15. The method of claim 14 wherein adjusting the support pressure includes one selected from the group including increasing the support pressure and decreasing the support pressure.
16. The method of claim 14 wherein determining if the removal rate of material from the top surface of the wafer over the edge periphery is acceptable includes identifying an amount of deflection associated with the edge periphery of the bottom surface of the wafer.
17. A method for controlling a removal rate of material from a top surface of a wafer during chemical mechanical polishing (CMP), the wafer being supported on a wafer chuck the method comprising:
applying a polishing pressure to the top surface of the wafer;
applying a support pressure to an edge periphery of a bottom surface of the wafer, wherein the support pressure is applied through a gap between an edge surface of the wafer chuck and the edge periphery of the bottom surface of the wafer, the edge periphery of the bottom surface of the wafer not being in direct contact with the wafer chuck
applying a vacuum pressure to the bottom surface of the wafer, the vacuum pressure being arranged to secure a portion of the bottom surface of the wafer that is not the edge periphery against the wafer chuck; and
adjusting the vacuum pressure to control the removal rate of material from the top surface of the wafer over the edge periphery.
18. An apparatus for controlling a removal rate of material from a top surface of a wafer supported on a wafer chuck during chemical mechanical polishing (CMP), the wafer being supported on the wafer chuck such that a portion of the wafer is in direct contact with the wafer chuck the apparatus comprising:
means for applying a polishing pressure to the top surface of the wafer; and
means applying a support pressure to an edge periphery of a bottom surface of the wafer, wherein the support pressure is applied through a gap between an edge surface of the wafer chuck and the edge periphery of the bottom surface of the wafer, the edge periphery of the bottom surface of the wafer not being in physical contact with the wafer chuck.
19. The apparatus of claim 18 wherein the means for applying the support pressure to the edge periphery of the bottom surface of the wafer includes means for distributing an air pressure on the edge periphery of the bottom surface of the wafer, the air pressure being arranged to act as an air bearing in the gap.
20. The apparatus of claim 18 wherein the means for applying the support pressure to the edge periphery of the bottom surface of the wafer includes means for distributing a fluid pressure on the edge periphery of the bottom surface of the wafer, the fluid pressure being arranged to act as fluid bearing in the gap.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for purifying the compound of Formula I
the process comprising:
(a) extracting an organic phase comprising: (i) the compound of Formula I; and (ii) one or more organic solvents, with an aqueous bisulfite solution, thereby forming an aqueous phase comprising a bisulfite adduct of the compound of Formula I; and
(b) regenerating the compound of Formula I in a precipitate form by:
(i) a process comprising: (1) extracting the aqueous phase containing the bisulfite adduct of the compound of Formula I provided in Step (a) with an organic phase comprising one or more water-miscible organic solvents, thereby forming an organic phase containing the compound of Formula I; and (2) mixing the organic phase provided in extracting Step (b)(i)(1) with water at a temperature suitable to precipitate the compound of Formula I; or
(ii) adding the aqueous phase prepared in Step (a) into an organic phase comprising one or more water-miscible organic solvents thereby precipitating the compound of Formula I; or
(iii) adding to the aqueous phase provided in Step (a) a carbonyl compound or an oxidant suitable to precipitate the compound of Formula I; or
(iv) a process comprising: (1) extracting the aqueous phase provided in Step (a) with an organic phase comprising at least one organic solvent and optionally a carbonyl compound or an oxidant compound; and (2) adding the organic phase obtained in extracting Step (b)(iv)(1) to a solvent or mixture of solvents in which the compound of Formula I is insoluble (an antisolvent) at a temperature suitable to precipitate the compound of Formula I.
2. The process of claim 1 wherein the bisulfite used to form the adduct of the compound of Formula I in Step (a) is sodium bisulfite.
3. The process of claim 1 wherein in Step (a), the organic phase comprises tert-butyl methyl ether and the extraction is carried out at a temperature of from \u22125\xb0 C. to about 10\xb0 C.
4. The process of claim 3 wherein the regeneration process used is that described in Step (b)(iv).
5. The process of claim 4 wherein the organic solvent used in Step (b)(iv) is tert-butyl methyl ether.
6. The process of claim 4 wherein the regeneration is carried out in the presence of a carbonyl compound.
7. The process of claim 6 wherein the carbonyl compound is a glyoxylic acid salt.
8. The process of claim 1 wherein, in Step (a), the bisulfite used to form the adduct is sodium bisulfite, the organic solvent is tert-butyl methyl ether and the extraction is carried out at \u22125\xb0 C. to 10\xb0 C., and wherein the regeneration process used is that described in Step (b)(iv), and wherein the regeneration process of Step (b)(iv) utilizes tert-butyl methyl ether as the organic phase and wherein a carbonyl compound is present in the form of a glyxoylic acid salt.
9. A process for purifying the compound of Formula I
the process comprising:
(a) forming an organic phase comprising a bisulfite adduct of the compound of Formula I and one or more organic solvents;
(b) extracting the bisulfite adduct of the compound of Formula I formed in Step (a) into an aqueous phase; and
(c) regenerating the compound of Formula I in a precipitate form by:
(i) a process comprising: (1) extracting the aqueous phase containing the bisulfite adduct of the compound of Formula I provided in Step (b) with an organic phase comprising one or more water-miscible organic solvents, thereby forming an organic phase containing the compound of Formula I; and (2) mixing the organic phase provided in extracting Step (c)(i)(1) with water at a temperature suitable to precipitate the compound of Formula I; or
(ii) adding the aqueous phase prepared in Step (b) into an organic phase comprising one or more water-miscible organic solvents thereby precipitating the compound of Formula I; or
(iii) adding to the aqueous phase provided in Step (b) a carbonyl compound or an oxidant suitable to precipitate the compound of Formula I; or
(iv) a process comprising: (1) extracting the aqueous phase provided in Step (b) with an organic phase comprising at least one organic solvent and optionally a carbonyl compound or an oxidant compound; and (2) adding the organic phase obtained in extracting Step (c)(iv)(1) to a solvent or mixture of solvents in which the compound of Formula I is insoluble (an antisolvent) at a temperature suitable to precipitate the compound of Formula I.
10. The process of claim 9 wherein the bisulfite used to form the adduct is sodium bisulfite.
11. The process of claim 9 wherein the organic solvent in Step (a) is ethyl acetate or a mixture of ethyl acetate and tert-butyl methyl ether.
12. The process of claim 9 wherein the extraction in Step (b) is carried out at \u22125\xb0 C. to 10\xb0 C.
13. The process of claim 9 wherein the regeneration process used is that described in Step (c)(iv).
14. The process of claim 13 wherein the organic solvent used in the regeneration process is tert-butyl methyl ether.
15. The process of claim 14 wherein the regeneration process used is the process of Step (c)(iv), and Step (c)(iv)(1) of the regeneration process is carried out in the presence of a carbonyl compound.
16. The process of claim 15 wherein the carbonyl compound used in the regeneration process is a glyoxylate salt.
17. The process of claim 9 wherein in Step (a), the bisulfite used to form the adduct is sodium bisulfite and the organic solvent is tert-butyl methyl ether, in Step (b) the extraction is carried out at \u22125\xb0 C. to 10\xb0 C., and wherein the regeneration process used is that described in Step (c)(iv), and is carried out using tert-butyl methyl ether as the organic solvent in the presence of a glyoxylate salt.