Control sheet reclaiming method with and the control chip architecture
Technical field
The present invention and a kind of semiconductor fabrication, particularly a kind of by coating control sheet reclaiming (the reclaim control/dummy wafer) method of (pre-coated) silicon nitride (SiN) on wafer (wafer) in advance with and the control chip architecture.
Background technology
Semiconductor subassembly utilizes highdensity integrated circuit technique to have sizable progress.Utilize the exploitation of stepper, high-resolution little shadow (lithography) equipment and etching technique, make semiconductor more quicken evolution.Usually, the step of making integrated circuit includes the fabrication steps in hundreds of roads, therefore processing procedure process complexity not only, and how effectively group to appoint the workload of process work bench and job specification also be the work of a complexity with the utilization of promoting resource.In manufacture process, make bottleneck and often occur in the production capacity that has influence on processing procedure in many fabrication steps at any time, for example, processing procedure speed, capacity utilization, apparatus of load density or the like all are the factors that influences production capacity.
Multiple internal connecting lines (multi-level interconnection) also is one of structure important in the integrated circuit.By multiplex conductor connect make the transistor (transistor), capacitor (capcitor) and the resistance basic building blocks such as (resistor) that are configured in Semiconductor substrate (substrate) can electrical couplings (couple) to finish specific function.Aluminum metal contacts as electrical with the intraconnections that titanium is used for semiconductor technology at large, general aluminum or aluminum alloy is formed on the silicon film, and the contact-making surface of this aluminium-silicon, aluminium/silicon/copper (AlSiCu) alloy can be used to make the material of more low-resistance structure as intraconnections (interconnection).Utilize copper (Cu) to become possibility based on the exploitation of Progress in technique and CMP (chemical mechanical polishing) is feasible as intraconnections.Low and because of the impedance of copper to electromigration (electro-migration) patience height, so be that the Cu processing procedure of material develops and becomes important techniques in the deep-sub-micrometer with copper.The control sheet (control/dummywafer) that present copper metallization (Cu metallization) is adopted must use Ta/TaN as barrier layer (barrier layer).For reclaiming utilization control sheet (reclaim control/dummy wafer), the Ta/TaN barrier layer must be removed, and can cause the consume of silicon (Si) material in the removal process more usually.The main at present method that adopts two kinds of reclaiming utilization control sheets, a kind of is to adopt sulfuric acid solution mixing hydrofluoric acid solution to remove above-mentioned metal level, however it needs higher temperature and etch-rate slow.Another kind of mode is to adopt chemical mechanical milling method, and just CMP (chemical mechanical polishing) removes metal level, and then utilizes hydrofluoric acid solution to remove silicon dioxide.But the cost of the method is too high.
Therefore at present be badly in need of a kind of method that can reclaiming utilization control sheet (reclaim control/dummy wafer).
Summary of the invention
Main purpose of the present invention provide a kind of by coating control sheet reclaiming (the reclaim control/dummy wafer) method of (pre-coated) silicon nitride (SiN) on wafer (wafer) in advance with and the control chip architecture.
A further object of the present invention is to provide a kind of control sheet reclaiming method that is applicable to copper wiring.
A kind of method of reclaiming utilization control sheet comprises: deposit a silicon nitride film (SiN film) on the control sheet; And the control sheet of coating film is soaked in the film that is beneficial to remove above-mentioned coating in the mixed solution, this mixed solution comprises HF, HNO
3, DIW (deionized water).Wherein above-mentioned mixed solution composition is HF: HNO
3: DIW (deionized water)=1: 6: 4, the HF concentration of mixed solution is 49%, HNO
3Concentration is 70%.The control sheet is immersed in and soaked four minutes under the condition of 200% over etching and the control sheet is immersed in operation at room temperature.
The control chip architecture of reclaiming utilization control sheet of the present invention comprises a substrate and a silicon nitride film (SiN film) and is formed on the substrate; And this control sheet can be soaked in the film that is beneficial to remove coating in the mixed solution, and this mixed solution comprises HF, HNO
3, DIW (deionized water).
Adopt said method can reduce the cost that the control sheet is recycled, improve recovery speed, and safer.
Description of drawings
Fig. 1 is a flow chart of the present invention.
Embodiment
The present invention for provide a kind of by coating control sheet reclaiming (the reclaim control/dummy wafer) method of (pre-coated) silicon nitride (SiN) on wafer (wafer) in advance with and the control chip architecture.Method of the present invention and structure are applicable to the recovery and the regeneration of the control sheet of copper wiring, and the effect of this method is not only with low cost and safer.
Consult Fig. 1, as controlling sheet (control/dummy wafer) substrate as an example, in order to limit the present invention, at first step 100 does not deposit a silicon nitride film (SiN film) on above-mentioned control sheet with chemical vapour deposition technique in boiler tube with a monocrystalline silicon.Follow the use of control sheet to carry out the thin film deposition (200) of main processing procedure subsequently.The film control that to grow up be can monitor by traditional using method of control sheet, monitoring program depositing of thin film or growth are beneficial to.
Finish after the main process thin film deposition, the reclaiming of control sheet can be utilized (reclaimcontrol/dummy wafer) usually, to save the cost expenditure.The present invention is that the control sheet with the coating film is soaked in the film that is beneficial to remove above-mentioned coating in the mixed acid solution.The present invention can be suitable for following structure, it must be appreciated that following parameter and aspect only do an explanation and a reference, and is non-in order to limit this
Scope of invention.
With reference to aspect | Reference configuration | Reference thickness (kA) |
B and S | SiN/PE-oxide/TaN/Ta SiN/PE-oxide/TaN/Ta/Cu | 1.15/4/0.15/1.2 1.15/4/0.15/1.2/10 |
ECP | SiN/PE-oxide/TaN/Fa/Cu | 1.15/4/0.15/1.2/20 |
CMP | SiN/PE-oxide/TaN/Ta/Cu | 1.15/4/0.15/1.2/100 |
The removal method that control sheet of the present invention (control and dummy wafer) is gone up the major metal layer is that it is immersed in the acid solution that mixes (300), and this acid solution comprises HF, HNO
3, DIW, HF: HNO
3: DIW (deionized water)=1: 6: 4, HF and HNO
3Concentration is respectively HF49%, HNO
370%.Under the condition of 200% over etching, soaked four minutes.Operation at room temperature.Above-mentioned solution also can corrode the SiN material, and approximately positive 100 dusts and the 200 dust back sides can be used the control sheet safely at least five times according to method of the present invention.