1. A method for preparing an aggregate comprising a plurality of particles, the method comprising forming a mixture comprising glass powder and an additive, forming green pellets from the mixture, coating the surface of the pellets with a refractory material and heating the pellets at a required temperature to produce a plurality of particles, the additive being such that it at least partially breaks down at the required temperature to generate gas, which gas is at least partially retained in the microstructure of the mixture to cause the formation of pores within the microstructure, the additive also being such that upon heating the additive and glass combine to produce a glass ceramic system.
2. A method according to claim 1, characterised in that the additive includes any of: a slag material; clay; a waste stream.
3-4. (canceled)
5. A method according to claim 1, characterised in that the additive includes one or more of any of the following additional components:
a binding agent; a soluble flux material; a strengthening agent, a bloating agent, a plasticiser, an iron rich substance; a material capable of containing heavy metals; a binding agent; a soluble flux; strengthening agent; a bloating agent; water treatment residues (WTR); waste sugar; micro silica; phosphates; borates.
6. A method according to claim 5, characterised in that the additional components are such that they at least partially break down at the required temperature to generate gas.
7. A method according to claim 5, characterised in that the additional components are such that upon heating they combine with the glass to produce a glass ceramic system.
8-10. (canceled)
11. A method according to claim 2, characterised in that the waste stream includes any of incinerated sewage sludge ash (ISSA), incinerated paper sludge ash (IPSA), various types of waste quarry fines, perlite waste, pulverised fuel ash (PFA) and contaminated soils and waste paint.
12. (canceled)
13. A method according to claim 1, characterised in that the method further comprises the step of introducing (e.g. mixing) the aggregate particles into a settable matrix to produce a building material.
14. (canceled)
15. A method according to claim 1, characterised in that the glass powder comprises glass particles substantially having a maximum dimension which is less than 75 \u03bcm.
16-18. (canceled)
19. A method according to claim 1, characterised in that the mixture includes between 60 and 95% glass by weight.
20-51. (canceled)
52. A method according to claim 1, characterised in that the step of forming the mixture into green pellets comprises at least one of pelletising, extruding or pressing the pellets from the mixture.
53-54. (canceled)
55. A method according to claim 1, characterised in that coating the pellets with a refractory material occurs after pelletisation.
56. A method according to claim 1, characterised in that the refractory material is any of limestone dust, silica dust, iron dust andor china clay, ball clay, calcium oxide, dolomite or other refractory powders.
57-58. (canceled)
59. A method according to claim 1, characterised in that the pellets are pre-heated at 110\xb0 C. to drive off mechanically held water.
60-61. (canceled)
62. A method according to claim 1, characterised in that the pellets are heated within the range 700 to 950\xb0 C.
63-64. (canceled)
65. A method according to claim 1, characterised in that the pellets are heated to the maximum temperature for between 10 and 60 minutes.
66-69. (canceled)
70. A method of producing green pellets, the method including the steps of forming a plurality of green pellets from a mixture comprising glass powder, and an additive, and a refractory material coating.
71. A method according to claim 70, characterised in that the mixture comprises a dry mixture including glass in the range 0-95% by weight and additives in the range 5-30% by weight.
72-82. (canceled)
83. A method for preparing aggregate particles, the method comprising forming a plurality of green pellets from a mixture comprising glass powder, and an additive, and a refractory material coating, sintering the green pellets so as to cause the pellets to expand to produce particles comprising a plurality of internal closed pores.
84-88. (canceled)
89. A method according to claim 83, characterised in that a reducing atmosphere is created during sintering in which localised reduction of various oxides of iron within the pellet in the presence of carbon may occur.
90-98. (canceled)
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 method of approximating eigensolutions for use in determining a profile of a structure formed on a semiconductor wafer, the method comprising:
obtaining a known set of eigenvectors associated with a first section of a hypothetical profile of the structure,
wherein the known set of eigenvectors is used to generate a simulated diffraction signal for the hypothetical profile;
obtaining a known characteristic matrix associated with a second section of a hypothetical profile; and
determining an approximated set of eigenvalues for the second section based on the known set of eigenvectors associated with the first section and the known characteristic matrix associated with the second section.
2. The method of claim 1, wherein the first section and the second section are portions of the same hypothetical profile.
3. The method of claim 1, wherein the first section and the second section are portions of different hypothetical profiles.
4. The method of claim 1, wherein one or more parameters that characterize the first section is different than one or more parameters that characterize the second section.
5. The method of claim 4, wherein the one or more parameters that characterize the first section and the one or more parameters that characterize the second section includes a line width parameter.
6. The method of claim 4, wherein the one or more parameters that characterize the first section and the one or more parameters that characterize the second section includes a pitch parameter.
7. The method of claim 1, wherein the first section corresponds to a different material than the second section.
8. The method of claim 1, wherein the profile of the structure varies in a first dimension.
9. The method of claim 8, wherein the profile of the structure varies in at least a second dimension in addition to the first dimension.
10. The method of claim 1, further comprising:
(a) obtaining a known set of eigenvalues associated with the first section;
(b) determining an auxiliary matrix based on the known set of eigenvectors and the known characteristic matrix;
(c) determining an approximated set of eigenvectors based on the auxiliary matrix;
(d) determining the approximated set of eigenvalues based on the approximated set of eigenvectors and the auxiliary matrix; and
(e) determining if a change between the known set of eigenvalues and the approximated set of eigenvalues meets a stop criterion;
(i) when the stop criterion is not met, repeating steps (b) to (e) using the determined approximated set of eigenvectors as the known set of eigenvectors in repeating step (b) and the determined auxiliary matrix as the known characteristic matrix in repeating step (b) and the determined approximated set of eigenvalues as the known set of eigenvalues in repeating step (e), and
(ii) when the stop criterion is met, using the approximated set of eigenvalues as the approximated set of eigenvalues for the second section.
11. The method of claim 10 further comprising:
determining a set of eigenvectors for the second section based on the known set of eigenvectors associated with the first section and the one or more approximated sets of eigenvectors determined in step (c) of claim 10.
12. The method of claim 11, wherein the set of eigenvalues and the set of eigenvectors are used in solving a system of coupled differential equations in a rigorous coupled wave analysis to generate a simulated diffraction signal for the second section.
13. The method of claim 12, wherein the simulated diffraction signal generated for the first section corresponds to a first incident light wavelength and the simulated diffraction signal generated for the second section corresponds to a second incident light wavelength.
14. The method of claim 12, wherein the simulated diffraction signal generated for the first section corresponds to a first angle of incidence and the simulated diffraction signal generated for the second section corresponds to a second angle of incidence.
15. The method of claim 12, wherein the simulated diffraction signal for the second section is stored in a library for use in a library-based process for determining the profile of a structure.
16. The method of claim 15, wherein the library-based process comprises:
obtaining a diffraction signal measured from directing an incident beam at the structure (a measured diffraction signal); and
comparing the measured diffraction signal to one or more simulated diffraction signals stored in the library to determine the profile of the structure.
17. The method of claim 12, wherein the simulated diffraction signal is generated as part of a regression-based process for determining the profile of a structure.
18. The method of claim 17, wherein the regression-based process comprises:
obtaining a diffraction signal measured from directing an incident beam at the structure (a measured diffraction signal);
comparing the measured diffraction signal to a first simulated diffraction signal; and
when the difference of the measured diffraction signal and the first simulated diffraction signal is not within a matching criterion:
generating a second simulated diffraction signal; and
repeating the comparing step using the second simulated diffraction signal.
19. A method of approximating eigensolutions for use in determining a profile of a structure formed on a substrate, the method comprising:
(a) obtaining a known set of eigenvectors and a known set of eigenvalues associated with a first section of a hypothetical profile of the structure;
(b) obtaining a known characteristic matrix associated with a second section of a hypothetical profile of the structure;
(c) determining an auxiliary matrix based on the known set of eigenvectors and the known characteristic matrix;
(d) determining an approximated set of eigenvectors based on the auxiliary matrix;
(e) determining an approximated set of eigenvalues based on the approximated set of eigenvectors and the auxiliary matrix; and
(f) determining if a change between the known set of eigenvalues and the approximated set of eigenvalues meets a stop criterion;
(i) when the stop criterion is not met, repeating steps (c) to (f) using the determined approximated set of eigenvectors as the known set of eigenvectors in repeating step (c) and the determined auxiliary matrix as the known characteristic matrix in repeating step (c) and the determined approximated set of eigenvalues as the known set of eigenvalues in repeating step (f), and
(ii) when the stop criterion is met, using the approximated set of eigenvalues as an approximated set of eigenvalues for the second section.
20. The method of claim 19 further comprising:
determining a set of eigenvectors for the second section based on the known set of eigenvectors associated with the first section and the one or more approximated sets of eigenvectors determined in step (d).
21. The method of claim 20, wherein the set of eigenvalues and eigenvectors are used in solving a system of coupled differential equations in a rigorous coupled wave analysis to generate a simulated diffraction signal for the second section.
22. The method of claim 21, wherein the simulated diffraction signal calculated using the second section is stored in a library for use in a library-based process for determining the profile of a structure.
23. The method of claim 21, wherein the simulated diffraction signal for the second section is generated as part of a regression-based process for determining the profile of a structure.
24. A system to approximate eigensolutions for use in determining a profile of a structure formed on a semiconductor wafer, the system comprising:
a memory having:
a known set of eigenvectors associated with a first section of a hypothetical profile of the structure,
wherein the known set of eigenvectors is used to generate a simulated diffraction signal for the hypothetical profile, and
a known characteristic matrix associated with a second section of a hypothetical profile; and
a processor configured to determine an approximated set of eigenvalues for the second section based on the known set of eigenvectors associated with the first section and the known characteristic matrix associated with the second section.
25. The system of claim 24,
wherein the memory has a known set of eigenvalues associated with the first section; and
wherein the processor is configured to:
(a) determine an auxiliary matrix based on the known set of eigenvectors and the known characteristic matrix,
(b) determine an approximated set of eigenvectors based on the auxiliary matrix,
(c) determine an approximated set of eigenvalues based on the approximated set of eigenvectors and the auxiliary matrix, and
(d) determine if a change between the known set of eigenvalues and the approximated set of eigenvalues meets a stop criterion;
(i) when the stop criterion is not met, repeat (a) to (d) using the determined approximated set of eigenvectors as the known set of eigenvectors in repeating (a) and the determined auxiliary matrix as the known characteristic matrix in repeating (a) and the determined approximated set of eigenvalues as the known set of eigenvalues in repeating (d), and
(ii) when the stop criterion is met, use the approximated set of eigenvalues as the approximated set of eigenvalues for the second section.
26. The system of claim 25, wherein the processor is further configured to determine a set of eigenvectors for the second section based on the known set of eigenvectors associated with the first section and the one or more approximated sets of eigenvectors determined in (b) of claim 25.
27. The system of claim 26, wherein the set of eigenvalues and the set of eigenvectors are used in solving a system of coupled differential equations in a rigorous coupled wave analysis to generate a simulated diffraction signal for the second section.
28. The system of claim 27, wherein the simulated diffraction signal for the second section is stored in a library for use in a library-based system configured to determine the profile of a structure.
29. The system of claim 28, wherein the library-based system comprises:
a detector configured to measure a diffraction signal from an incident beam directed at the structure (a measured diffraction signal); and
a processor configured to compare the measured diffraction signal to one or more simulated diffraction signals stored in the library to determine the profile of the structure.
30. The system of claim 27, wherein the simulated diffraction signal for the second section is generated as part of a regression-based system configured to determine the profile of a structure.
31. The system of claim 30, wherein the regression-based system comprises:
a detector configured to measure a diffraction signal from an incident beam directed at the structure (a measured diffraction signal); and
a processor configured to:
compare the measured diffraction signal to a first simulated diffraction signal, and
when the difference of the measured diffraction signal and the first simulated diffraction signal is not within a matching criterion:
generate a second simulated diffraction signal; and
comparing the measured diffraction signal to the second simulated diffraction signal.
32. A computer-readable storage medium containing computer executable instructions for causing a computer to approximate eigensolutions for use in determining a profile of a structure formed on a semiconductor wafer, comprising instructions for:
obtaining a known set of eigenvectors associated with a first section of a hypothetical profile of the structure,
wherein the known set of eigenvectors is used to generate a simulated diffraction signal for the hypothetical profile;
obtaining a known characteristic matrix associated with a second section of a hypothetical profile; and
determining an approximated set of eigenvalues for the second section based on the known set of eigenvectors associated with the first section and the known characteristic matrix associated with the second section.
33. The computer-readable medium of claim 32, further comprising instructions for:
(a) obtaining a known set of eigenvalues associated with the first section;
(b) determining an auxiliary matrix based on the known set of eigenvectors and the known characteristic matrix;
(c) determining an approximated set of eigenvectors based on the auxiliary matrix;
(d) determining an approximated set of eigenvalues based on the approximated set of eigenvectors and the auxiliary matrix; and
(e) determining if a change between the known set of eigenvalues and the approximated set of eigenvalues meets a stop criterion;
(i) when the stop criterion is not met, repeating steps (b) to (e) using the determined approximated set of eigenvectors as the known set of eigenvectors in repeating step (b) and the determined auxiliary matrix as the known characteristic matrix in repeating step (b) and the determined approximated set of eigenvalues as the known set of eigenvalues in repeating step (e), and
(ii) when the stop criterion is met, using the approximated set of eigenvalues as the approximated set of eigenvalues for the second section.
34. The computer-readable medium of claim 33 further comprising instructions for:
determining a set of eigenvectors for the second section based on the known set of eigenvectors associated with the first section and the one or more approximated sets of eigenvectors determined in step (c) of claim 33.
35. The computer-readable medium of claim 34, wherein the set of eigenvalues and set of eigenvalues are used in solving a system of coupled differential equations in a rigorous coupled wave analysis to generate a simulated diffraction signal for the second section.
36. The computer-readable medium of claim 35, wherein the simulated diffraction signal for the second section is stored in a library for use in a library-based process for determining the profile of a structure.
37. The computer-readable medium of claim 36, wherein the library-based process comprises:
obtaining a diffraction signal measured from directing an incident beam at the structure (a measured diffraction signal); and
comparing the measured diffraction signal to one or more simulated diffraction signals stored in the library to determine the profile of the structure.
38. The computer-readable medium of claim 35, wherein the simulated diffraction signal is generated as part of a regression-based process for determining the profile of a structure.
39. The computer-readable medium of claim 38, wherein the regression-based process comprises:
obtaining a diffraction signal measured from directing an incident beam at the structure (a measured diffraction signal);
comparing the measured diffraction signal to a first simulated diffraction signal; and
when the difference of the measured diffraction signal and the first simulated diffraction signal is not within a matching criterion:
generating a second simulated diffraction signal; and
repeating the comparing step using the second simulated diffraction signal.