The chemical mechanical polishing device of wafer
Technical field
The invention relates to a kind of chemical mechanical polishing device of wafer, particularly detect the chemical mechanical polishing device of the wafer of grinding endpoint relevant for a kind of IN-SITU formula, its grinding pad has dismountable printing opacity form.When the printing opacity form because do not seep water afters use for a long time, and cause the printing opacity form fuzzy and when causing the grinding endpoint erroneous judgement, can directly replace the printing opacity form, to improve the correctness of detecting grinding endpoint.
Background technology
As everyone knows, in ultra-large type kind body circuit (ULSI) processing procedure, often need form insulating barriers such as silicon dioxide at semiconductor wafer surface, and metal levels such as tungsten or copper, and have only at present by chemical mechanical milling method, just can make above-mentioned insulating barrier and metal level reach comprehensive smooth effect.
Below introduce the structure and the grinding principle thereof of the chemical mechanical polishing device of traditional wafer.
Consulting Fig. 1, is the profile that shows the chemical mechanical polishing device of traditional wafer.The chemical mechanical polishing device of wafer described herein is an in-situ detecting grinding endpoint type.
At first, be mainly used to fixing and rotate wafer 120 to be ground for having the rotation carrier (rotating carrier) 110 of drive link 100.Have the grinding plate 140 of rotary main shaft 130, rotate by the transmission of rotary main shaft 130.Moreover, grinding plate 140 has the light emitted device 1401 of emission of lasering beam 1400 and detecting via the light detector 1402 of 120 laser light reflected bundles 1400 of wafer, terminal point with detecting cmp processing procedure, the material of grinding plate 140 is a translucent material, therefore, laser beam 1400 is able to be sent to by light emitted device 1401 outside of grinding plate 140.
Consult the profile that Fig. 2 shows traditional grinding pad.Grinding pad 150 is to be fixed in grinding plate 140 by gum 160, has an opening 1501 in order to printing opacity form 1502 to be set, and printing opacity form 1502 is to be fixed in opening 1501, and passes through for above-mentioned particular light ray 1400.
Consult Fig. 1, grind 170 supplies of slurry supply system by one and grind slurry 180 to grinding pad 150 surfaces.Wafer 120 is with grinding pad 150 surface and grind slurry 150 and contact and rotate by exerting pressure of carrier 110 of rotation.At this moment, above-mentioned grinding pad 150 is to rotate along with grinding plate 140, therefore, and by the friction that independent rotation produced separately between wafer 120 and the grinding pad 150, and wafer 120 surface with grind slurry 150 chemical actions that taken place, can carry out the cmp processing procedure.
Moreover, the mode of the chemical mechanical polishing device detecting grinding endpoint of the wafer of in-situ type, be to reflect via wafer 120, and judge whether to reach grinding endpoint by the optical characteristics of the laser beam 1400 that light emitted device 1401 sent by 1402 detectings of light detector., have a detailed description in 428 at United States Patent (USP) 5,559 about the structure of the chemical mechanical polishing device of above-mentioned traditional wafer and action, do not repeat them here.Its major defect is:
1, when carrying out the chemical machinery instrument when being idle for too long, inevitably grinds the steam of slurry and will invade grinding pad, and make the surface of printing opacity form 1502 that vaporific phenomenon take place, thereby change the light transmittance of printing opacity form 1502.Therefore will cause the erroneous judgement of grinding endpoint and produce scrap products.
2, because traditional printing opacity form 1502 is the openings 1501 that are fixed in grinding pad 150, if will address the above problem, no matter whether grinding pad may be used, and whole grinding pad must be changed, quite uneconomical.And in the process of changing grinding pad,, more need to allocate extra manpower to carry out the relevant action of changing grinding pad except stopping the running of instrument.
3 moreover, grinding pad must be arranged at grinding plate accurately, above-mentioned all complicated actions will reduce the efficient of processing procedure.
Summary of the invention
Main purpose of the present invention provides a kind of chemical mechanical polishing device of wafer, is provided with dismountable printing opacity form, when the printing opacity form blurs because of making moist, only need change the printing opacity form, need not change whole grinding pad; Moreover, because the printing opacity form is to be close to grinding plate, more reduce the chance that blooming takes place because of steam in printing opacity form bottom, reach simplification and change the step of grinding pad, reduce production costs and effectively solve the purpose that causes grinding endpoint to judge by accident because of infiltration.
The object of the present invention is achieved like this: a kind of chemical mechanical polishing device of wafer is characterized in that: its grinding plate has the light emitted device of emission particular light ray and detecting via the light detector of the particular light ray that wafer reflected; The grinding pad that is arranged on this grinding plate has first opening; Be arranged at this first opening the transmissive member reassembling type; Grind the supply of slurry supply system and grind slurry to this grinding pad surface; Rotation carrier fixing also rotates this wafer, and this crystal column surface carries out the cmp processing procedure with grinding to starch to contact with grinding pad.
This particular light ray is a laser light.This grinding pad comprises that having second opening, first substrate is arranged on this grinding plate, and second substrate with the 3rd opening is arranged on this first substrate, and this second opening is to overlap first opening that constitutes this grinding pad each other with the 3rd opening.The material model of this first substrate is subaIV.The material model of this second substrate is IC-1000.This transmissive member is to be arranged at this second opening.
Further specify below in conjunction with preferred embodiment and accompanying drawing.
Description of drawings
Fig. 1 is the generalized section of the chemical mechanical polishing device of traditional wafer.
Fig. 2 is the generalized section of traditional grinding pad.
Fig. 3 is the generalized section of the chemical mechanical polishing device of wafer of the present invention.
Fig. 4 is the generalized section of grinding pad of the present invention.
Embodiment
Consult shown in Figure 3ly, the chemical mechanical polishing device of the described wafer of the embodiment of the invention is an in-situ detecting grinding endpoint type.
At first, be mainly used to fixing and rotate a wafer 220 to be ground for having the rotation carrier 210 of drive link 200.Have the grinding plate 240 of rotary main shaft 230, rotate by the transmission of rotary main shaft 230.Moreover, grinding plate 240 has the light emitted device 2401 of emission of lasering beam 2400 and detecting via the light detector 2402 of 220 laser light reflected bundles 2400 of wafer, terminal point with detecting cmp processing procedure, the material of above-mentioned grinding plate 240 is a translucent material, therefore, laser beam 2400 is able to be sent to by light emitted device 2401 outside of grinding plate 240.
Consult shown in Figure 4ly, grinding pad 250 is to be fixed in above-mentioned grinding plate 240 by gum 260, and its structure is as follows:
First substrate 2501 has an opening, and its material model is subaIV, is arranged at grinding plate 240;
Second substrate 2502 has another opening 2503, and its material model is IC-1000, is arranged at first substrate.The opening of above-mentioned first substrate 2501 and second substrate 2502 is to overlap each other, and printing opacity form 2504 promptly is arranged at the opening of first substrate 2501.Present embodiment, because it is this printing opacity form 2504 is can be by user's dismounting in the opening of first substrate 250, obviously different with the structure of traditional grinding pad.
In addition, consult Fig. 3, grind 270 supplies of slurry supply system by one and grind slurry 280 to grinding pad 250 surfaces.Wafer 220 is with grinding pad 250 surface and grind slurry 250 and contact and rotate by exerting pressure of carrier 210 of rotation.At this moment, above-mentioned grinding pad 250 is to rotate along with grinding plate 240, therefore, and by being independent rotation produced separately friction between wafer 220 and the grinding pad 250, and wafer 220 surface with grind slurry 250 chemical actions that taken place, can carry out the cmp processing procedure.
Moreover, the mode of the chemical mechanical polishing device detecting grinding endpoint of the wafer of in-situ type, be, and the wavelength of the laser beam 2400 that by light emitted device 2401 sent 220 that reflected via wafer, and judge whether to reach grinding endpoint by light detector 2402 detecting.
What pay special attention to is, when the printing opacity form of grinding pad is fuzzy because steam infiltrates, will influence the wavelength of the laser beam of detecting grinding endpoint, and when causing the erroneous judgement of grinding endpoint.Structure of the present invention, the user only needs directly to remove this printing opacity form, and residues in moisture on the grinding plate with the non-dust cloth wiping, and stick new printing opacity form again and get final product, and in the conventional art, the whole grinding pad of necessary replacing.
Moreover, because printing opacity form of the present invention is to be close to grinding plate, more reduce the chance that blooming takes place because of steam in printing opacity form bottom.
Therefore, the present invention more can reduce production costs and save manpower except simplifying the step of changing and service time, and effectively solves the problem that causes the grinding endpoint erroneous judgement because of infiltration, and the service efficiency that improves grinding pad.
Though the present invention discloses as above with preferred embodiment, so it is not in order to limiting protection scope of the present invention, anyly has the knack of this skill person, and without departing from the spirit and scope of the present invention, a little change and the retouching done all falls within protection scope of the present invention.