1. A method of manufacturing a semiconductor device, comprising the steps of:
(a) preparing a semiconductor substrate;
(b) forming a first insulating film over the main surface of the semiconductor substrate;
(c) forming an element isolating trench in the first insulating film and the semiconductor substrate by plasma dry etching of the first insulating film and the semiconductor substrate;
(d) forming a second insulating film over the main surface of the semiconductor substrate so as to fill the trench;
(e) removing the second insulating film outside the trench by CMP, while leaving the second insulating film in the trench; and
(f) removing the first insulating film by wet etching to expose the semiconductor substrate,
wherein in the step (f), the first insulating film is wet etched while applying light of 140 lux or greater to at least a portion of the main surface of the semiconductor substrate.
2. The method of manufacturing a semiconductor device according to claim 1,
wherein in the step (f), the first insulating film is wet etched while applying light of 140 lux or greater to at least a portion of the main surface of the semiconductor substrate which is rotating.
3. The method of manufacturing a semiconductor device according to claim 2,
wherein in the step (f), the first insulating film is wet etched by supplying an etching solution to be used for etching of the first insulating film to the main surface of the rotating semiconductor substrate.
4. The method of manufacturing a semiconductor device according to claim 3,
wherein in the step (f), any of the regions of the main surface of the semiconductor substrate has a period of being irradiated with light of 140 lux or greater during wet etching of the first insulating film.
5. The method of manufacturing a semiconductor device according to claim 4,
wherein the first insulating film is an oxide film.
6. The method of manufacturing a semiconductor device according to claim 5,
wherein in the step (b), the first insulating film is formed by thermal oxidation.
7. The method of manufacturing a semiconductor device according to claim 6,
wherein the method further comprises the step of, after the step (b) but before the step (c), (b1) forming a third insulating film over the first insulating film;
wherein in the step (c), an element isolating trench is formed in the third insulating film, the first insulating film, and the semiconductor substrate by subjecting the third insulating film, the first insulating film, and the semiconductor substrate to plasma dry etching, and
wherein the method further comprises the step of, after the step (e) but before the step (f), (e1) removing the third insulating film to expose the first insulating film.
8. The method of manufacturing a semiconductor device according to claim 7, wherein the third insulating film is a silicon nitride film.
9. The method of manufacturing a semiconductor device according to claim 8, wherein in the step (d), the second insulating film is formed by plasma CVD.
10. The method of manufacturing a semiconductor device according to claim 9, wherein in the step (d), the second insulating film is formed by high-density plasma CVD.
11. The method of manufacturing a semiconductor device according to claim 10, wherein the second insulating film is a silicon oxide film.
12. The method of manufacturing a semiconductor device according to claim 11, wherein in the step (f), the first insulating film is wet etched while having no resist layer on the main surface of the semiconductor substrate.
13. The method of manufacturing a semiconductor device according to claim 12, wherein when after the step (f), the insulating film is wet etched with the insulating film and a resist layer lying thereon on the main surface of the semiconductor substrate to expose the semiconductor substrate, the main surface of the semiconductor substrate is prevented from irradiation of light having 100 lux or greater thereto.
14. The method of manufacturing a semiconductor device according to claim 13, wherein the insulating film is for a gate insulating film of MISFET.
15. A method of manufacturing a semiconductor device, comprising the steps of:
(a) preparing a semiconductor substrate;
(b) forming a first insulating film over the main surface of the semiconductor substrate;
(c) forming an element isolating trench in the first insulating film and the semiconductor substrate by plasma dry etching of the first insulating film and the semiconductor substrate;
(d) forming a second insulating film over the main surface of the semiconductor substrate so as to fill the trench;
(e) removing the second insulating film outside the trench by CMP, while leaving the second insulating film in the trench; and
(f) removing the first insulating film by wet etching to expose the semiconductor substrate,
wherein in the step (f), the first insulating film is wet etched while applying light to the main surface of the semiconductor substrate, and
wherein when after the step (f), the insulating film is wet etched with the insulating film and a resist layer lying thereon on the main surface of the semiconductor substrate to expose the semiconductor substrate, the illuminance of the main surface of the semiconductor substrate is made lower than the illuminance of the main surface of the semiconductor substrate in the step (f).
16. The method of manufacturing a semiconductor device according to claim 15, wherein the insulating film is for a gate insulating film of MISFET.
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. An apparatus for producing a xylene isomer from a feedstock comprising olefins and an aromatic compound having at least six carbon atoms; said apparatus comprising:
a) a feedstock conduit transporting said feedstock;
b) a reaction zone comprising at least a first reactor containing catalyst adapted for transalkylation and olefin conversion comprising an acidic molecular sieve and at least one metal component, said reaction zone having at least one inlet and at least one outlet, wherein the inlet is in direct fluid communication with said feedstock conduit;
c) a reaction zone product distillation assembly comprising at least one distillation column, said reaction zone product distillation assembly having at least one inlet in fluid communication with the outlet of said reaction zone and an outlet, said reaction zone product distillation assembly being adapted to discharge a stream comprising C8 aromatics from the outlet;
d) a xylene distillation column having an inlet in fluid communication with the outlet of said reaction zone product distillation assembly and a first outlet, said xylene distillation column being adapted to discharge a stream comprising at least two xylene isomers from the first outlet;
e) a selective xylene isomer separation assembly having an inlet in fluid communication with the first outlet of said xylene distillation column, a first outlet, and a second outlet, said selective xylene isomer separation assembly being adapted to discharge a xylene isomer from the first outlet and discharge a non-equilibrium xylene isomer stream depleted in said xylene isomer from the second outlet; and
f) a xylene isomerization zone containing a xylene isomerization catalyst, the xylene isomerization zone having at least one inlet and at least one outlet, wherein the inlet is in fluid communication with the second outlet of said selective xylene isomer separation assembly and the outlet is in fluid communication with the inlet of said xylene distillation column.
2. The apparatus of claim 1 further comprising a feedstock distillation apparatus having a feedstock inlet and an outlet; said feedstock distillation apparatus being adapted to discharge a stream comprising olefins and an aromatic compound having at least six carbon atoms from the outlet; the outlet being in direct fluid communication with said reaction zone inlet via said feedstock conduit.
3. The apparatus of claim 1 further comprising an olefin removal apparatus having an inlet in fluid communication with the first outlet of said xylene distillation column and an outlet in fluid communication with the inlet of said selective xylene isomer separation assembly.
4. The apparatus of claim 3 wherein the olefin removal apparatus is a clay treater.
5. The apparatus of claim 1 wherein said xylene isomerization zone outlet is in fluid communication with said reaction zone product distillation assembly inlet.
6. The apparatus of claim 1 further comprising a isomerate distillation assembly comprising at least one distillation column, the isomerate distillation assembly having at least one inlet in fluid communication with the outlet of said xylene isomerization zone and an outlet, said isomerate distillation assembly being adapted to discharge a stream comprising C8 aromatics from the outlet and the outlet being in fluid communication with the inlet of said xylene distillation column.
7. The apparatus of claim 6 wherein the isomerate distillation assembly comprises:
a) a lights column having an inlet in fluid communication with the outlet of said xylene isomerization zone, a first outlet, and a second outlet, said lights column being adapted to discharge a stream comprising benzene from the first outlet and a stream comprising C7+ aromatics from the second outlet; and
b) a deheptanizer column having an inlet in fluid communication with the second outlet of said lights column, a first outlet, and a second outlet, said deheptanizer column being adapted to discharge a stream comprising toluene from the first outlet and a stream comprising C8+ aromatics from the second outlet.
8. The apparatus of claim 7 wherein at least one of the first outlet of the lights column and the first outlet of the deheptanizer column is in fluid communication with the inlet of the reaction zone.
9. The apparatus of claim 1 wherein the xylene distillation column further comprises a second outlet, the second outlet being in fluid communication with the inlet of the reaction zone.
10. The apparatus of claim 9 wherein the xylene distillation column is further adapted to discharge a stream comprising C9+ aromatics from the second outlet.
11. The apparatus of claim 9 further comprising a purge column having an inlet in fluid communication with the second outlet of the xylene distillation column, a first outlet in fluid communication with the inlet communication with the inlet of the reaction zone, and a second outlet discharging a purge stream.
12. The apparatus of claim 1 wherein the reaction zone product distillation assembly comprises:
a) a stripper column having an inlet in fluid communication with the outlet of said reaction zone and an outlet, said stripper column being adapted to discharge a stream comprising C6+ aromatics from the outlet;
b) a benzene column having an inlet in fluid communication with the outlet of said stripper column, a first outlet, and a second outlet, said benzene column being adapted to discharge a stream comprising benzene from the first outlet and a stream comprising C7+ aromatics from the second outlet; and
c) a toluene column having an inlet in fluid communication with the second outlet of said benzene column, a first outlet, and a second outlet, said toluene column being adapted to discharge a stream comprising toluene from the first outlet and a stream comprising C8+ aromatics from the second outlet, the second outlet being in fluid communication with the xylene distillation column.
13. The apparatus of claim 12 wherein at least one of the first outlet of the toluene column and the first outlet of the benzene column is in fluid communication with the inlet of the reaction zone.
14. The apparatus of claim 1 wherein the reaction zone further comprises the xylene isomerization zone wherein the xylene isomerization zone inlet is in fluid communication with an outlet of the first reactor and the xylene isomerization zone outlet is in fluid communication with the inlet of said reaction zone product distillation assembly.
15. The apparatus of claim 1 wherein the reaction zone further comprises the xylene isomerization zone and the reaction zone is adapted to contain the transalkylation and olefin conversion catalyst in a first bed and the xylene isomerization catalyst in a second bed; the reaction zone inlet being in fluid communication with the first bed, the xylene isomerization zone inlet being in fluid communication with the second bed, an outlet of the first bed being in fluid communication with the second bed, and the xylene isomerization zone outlet being in fluid communication with the second bed and the inlet of said reaction zone product distillation assembly.
16. An apparatus for producing a xylene isomer from a feedstock comprising olefins and an aromatic compound having at least six carbon atoms; said apparatus comprising:
a) a feedstock distillation apparatus having a feedstock inlet and an outlet; said feedstock distillation apparatus being adapted to discharge a stream comprising olefins and an aromatic compound having at least six carbon atoms from the outlet;
b) a reaction zone comprising at least a first reactor containing catalyst adapted for transalkylation and olefin conversion comprising an acidic molecular sieve and at least one metal component, said reaction zone having at least one inlet and at least one outlet;
c) a conduit providing fluid communication from the feedstock distillation outlet to the reaction zone inlet; said conduit providing no fluid communication to an olefin removal zone;
d) a reaction zone product distillation assembly comprising at least one distillation column, said reaction zone product distillation assembly having at least one inlet in fluid communication with the outlet of said reaction zone and an outlet, said reaction zone product distillation assembly being adapted to discharge a stream comprising C8 aromatics from the outlet;
e) a xylene distillation column having an inlet in fluid communication with the outlet of said reaction zone product distillation assembly and a first outlet, said xylene distillation column being adapted to discharge a stream comprising at least two xylene isomers from the first outlet;
f) a selective xylene isomer separation assembly having an inlet in fluid communication with the first outlet of said xylene distillation column, a first outlet, and a second outlet, said selective xylene isomer separation assembly being adapted to discharge a xylene isomer from the first outlet and discharge a non-equilibrium xylene isomer stream depleted in said xylene isomer from the second outlet; and
g) a xylene isomerization zone containing a xylene isomerization catalyst, the xylene isomerization zone having at least one inlet and at least one outlet, wherein the inlet is in fluid communication with the second outlet of said selective xylene isomer separation assembly and the outlet is in fluid communication with the inlet of said xylene distillation column.
17. An apparatus for producing a xylene isomer from a feedstock comprising olefins, C8 aromatic compounds, and C9+ aromatic compounds; said apparatus comprising:
a) a feedstock distillation apparatus having a feedstock inlet a first outlet and a second outlet; said feedstock distillation apparatus being adapted to discharge a stream comprising olefins and C9+ aromatic compounds from the first outlet and a stream comprising C8 aromatic compounds from the second outlet;
b) a reaction zone comprising at least a first reactor containing catalyst adapted for transalkylation and olefin conversion comprising an acidic molecular sieve and at least one metal component, said reaction zone having at least one inlet and at least one outlet;
c) a first conduit providing fluid communication from the first outlet of the feedstock distillation apparatus to the reaction zone inlet; said first conduit providing no fluid communication to an olefin removal zone;
d) a reaction zone product distillation assembly comprising at least one distillation column, said reaction zone product distillation assembly having at least one inlet in fluid communication with the outlet of said reaction zone and an outlet, said reaction zone product distillation assembly being adapted to discharge a stream comprising C8 aromatics from the outlet;
e) a xylene distillation column having an inlet in fluid communication with the outlet of said reaction zone product distillation assembly, a first outlet and a second outlet, said xylene distillation column being adapted to discharge a stream comprising at least two xylene isomers from the first outlet and a stream comprising C9+ aromatic compounds from the second outlet, the second outlet being in fluid communication with the reaction zone inlet;
f) a selective xylene isomer separation assembly having an inlet, a first outlet, and a second outlet, said selective xylene isomer separation assembly being adapted to discharge a xylene isomer from the first outlet and discharge a non-equilibrium xylene isomer stream depleted in said xylene isomer from the second outlet;
g) a second conduit providing fluid communication between the first outlet of said xylene distillation column and the inlet of the selective xylene isomer separation assembly, the second conduit comprising an olefin removal zone;
h) a third conduit providing fluid communication between the second outlet of the feedstock distillation apparatus and the inlet of the xylene distillation column; and
g) a xylene isomerization zone containing a xylene isomerization catalyst, the xylene isomerization zone having at least one inlet in fluid communication with the second outlet of said selective xylene isomer separation assembly, and at least one outlet in fluid communication with the inlet of said xylene distillation column.
18. The apparatus of claim 17 wherein the feedstock distillation apparatus being further adapted to produce a stream comprising at least one of benzene and toluene from a third outlet, said third outlet being in direct fluid communication with the reaction zone inlet.
19. The apparatus of claim 17 wherein the third conduit provides no fluid communication with an olefin removal zone.