Semiconductor device manufacturing: process – Chemical etching – Combined with the removal of material by nonchemical means
Reexamination Certificate
2001-11-29
2004-08-17
Vinh, Lan (Department: 1765)
Semiconductor device manufacturing: process
Chemical etching
Combined with the removal of material by nonchemical means
C438S692000, C438S614000, C451S041000
Reexamination Certificate
active
06777335
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polishing method, and to be more specific, relates to a polishing method using a polishing pad having a polishing part in which abrasive is dispersed, and an aqueous chemical mechanical polishing solution. The polishing method in the invention can be used favorably for the polishing of precision materials of various fields, for example, in the connection formation process of a DRAM, a high-speed logic LSI, or other semiconductor device requiring mixed installation of fine connections of approximately 0.1 &mgr;m to wide connections of approximately 100 &mgr;m. The polishing method in the invention is also especially favorable for polishing applications that require the attainment of a high degree of surface flatness.
2. Description of the Related Art
Chemical mechanical polishing, referred to as CMP, has been conventionally used for polishing the surfaces of semiconductor wafers and the like. In CMP, polishing is performed by sliding while pressing a surface to be polished of the wafer and the like against a disk-like polishing pad and at the same time, pouring a slurry, in which abrasive is dispersed, onto the polishing pad. However, it is difficult to supply the slurry (the abrasive in particular), which is poured from above, between the surface to be polished and polishing surface of the polishing pad, which are pressed against each other at high pressure, and it is said that the actual amount of functioning slurry is less than 1% of the total amount supplied. Moreover, this slurry is expensive and furthermore, vast costs are required for the treatment of used slurry.
Also, in cases where a slurry containing the abrasive is used to polish a surface wherein relatively soft parts and relatively hard parts coexist, since excessive polishing of the soft parts (the concave formed as a result is referred to as “erosion”) cannot be prevented adequately, a limit is placed on the surface flatness that can be achieved in some cases. In particular, in the case where damascene connections are formed in the process of manufacturing a semiconductor wafer or other semiconductor device, the conductor layer is the soft part and the semiconductor layer, the barrier metal layer or the like is the hard part, and excessive polishing of the conductor layer will be a critical problem.
Polishing pads, in which the abrasive is contained, have been disclosed in Japanese Unexamined Patent Publication No. Hei-10-329032, Japanese Unexamined Patent Publication No. Hei-11-151659, Japanese Unexamined Patent Publication No. Hei-11-188647, Japanese Unexamined Patent Publication No. Hei-11-207632 and the like. However, adequate removal rates cannot be obtained with these polishing pads, especially in the polishing of a surface to be polished containing a metal such as tungsten, copper and aluminum.
SUMMARY OF THE INVENTION
The present invention can resolve the above problems, and an object thereof is to provide a polishing method, with which a surface of high flatness can be obtained without fail at a high removal rate and in a stable manner, and, in particular, provide a polishing method, with which the above effects can be obtained even for a surface to be polished that contains a metal such as copper, tungsten and the like.
This invention is described as follows.
1. A polishing method, characterized in that a surface to be polished of an object to be polished is polished by using a polishing pad while existing an aqueous chemical mechanical polishing solution containing an oxidizing agent between polishing surface of the above-mentioned polishing pad equipped with a polishing part that contains abrasive, and the above-mentioned surface to be polished of the above-mentioned object to be polished.
2. The polishing method according to 1 above wherein the above-mentioned abrasive is comprised of at least one selected from the group consisting of ceria, silica, alumina, titanium oxide, chromium oxide, manganese dioxide, dimanganese trioxide, iron oxide, zirconium oxide, silicon carbide, boron carbide, diamond and barium carbonate.
3. The polishing method according to 2 above wherein the above-mentioned polishing part is formed by solidifying an aqueous dispersion in which a matrix material and abrasive are respectively dispersed and contained.
4. The polishing method according to 3 above wherein abrasive is not contained in the above-mentioned aqueous chemical mechanical polishing solution.
5. The polishing method according to 4 above wherein at least one multivalent metal ion selected from the group consisting of multivalent ions of aluminum, titanium, chromium, manganese, iron, copper, zinc and cerium is further contained in the above-mentioned aqueous chemical mechanical polishing solution.
6. The polishing method according to 5 above wherein an organic acid is contained in the above-mentioned aqueous chemical mechanical polishing solution.
7. The polishing method according to 6 above wherein the above-mentioned surface to be polished of the above-mentioned object to be polished contains at least one element selected from the group consisting of metal elements belonging to the group 3 to 13.
8. The polishing method according to 7 above, which is to be used in the manufacture of a semiconductor device.
9. The polishing method according to 4 above wherein at least one heterocyclic compound selected from the group consisting of a condensed ring compound composed of a nitrogen-atom-containing penta-heterocyclic compound or a nitrogen-atom-containing hexa-heterocyclic compound and a benzene ring or a naphthalene ring is further contained in the above-mentioned aqueous chemical mechanical polishing solution.
10. The polishing method according to 9 above, which is to be used in the manufacture of a semiconductor device.
11. The polishing method according to 2 above wherein the above-mentioned polishing part is formed by solidifying an aqueous dispersion containing dispersed composite particles where abrasive is attached to a matrix material.
12. The polishing method according to 11 above wherein abrasive is not contained in the above-mentioned aqueous chemical mechanical polishing solution.
13. The polishing method according to 12 above wherein at least one multivalent metal ion selected from the group consisting of multivalent ions of aluminum, titanium, chromium, manganese, iron, copper, zinc and cerium is further contained in the above-mentioned aqueous chemical mechanical polishing solution.
14. The polishing method according to 13 above wherein an organic acid is contained in the above-mentioned aqueous chemical mechanical polishing solution.
15. The polishing method according to 14 above wherein the above-mentioned surface to be polished of the above-mentioned object to be polished contains at least one element selected from the group consisting of metal elements belonging to the group 3 to 13.
16. The polishing method according to 15 above, which is to be used in the manufacture of a semiconductor device.
17. The polishing method according to 12 above wherein at least one heterocyclic compound selected from the group consisting of a condensed ring compound composed of a nitrogen-atom-containing penta-heterocyclic compound or a nitrogen-atom-containing hexa-heterocyclic compound and a benzene ring or a naphthalene ring is further contained in the above-mentioned aqueous chemical mechanical polishing solution.
18. The polishing method according to 17 above wherein an organic acid is contained in the above-mentioned aqueous chemical mechanical polishing solution.
19. The polishing method according to 18 above wherein the above-mentioned surface to be polished of the above-mentioned object to be polished contains copper.
20. The polishing method according to 19 above, which is to be used in the manufacture of a semiconductor device.
According to the polishing method in the invention, a surface having high flatness can be obtained at a high removal rate and in a stable manner. In particular, since a slurry that contains an a
JSR Corporation
Vinh Lan
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