TW414994B - Method of detecting semiconductor wafer quality or defect - Google Patents

Abstract

A method of detecting wafer quality or wafer defect is provided. The method comprises performing cleaning, oxidation and etching process repeatedly on a newly formed wafer to expose crystal original pits (COP) which is latent or appeared on the wafer surface. The amount of COP is measured using Tencor detecting machine or the like. The method can detect the latent or surface COP easily and precisely without using expensive KLA detecting machine or the like.

Description

414994 V. Description of the invention (1) The present invention relates to a method for inspecting the quality (or defect) of a wafer in a semiconductor process. It mainly firstly cleans, cleans, oxidizes, and etches new wafers repeatedly, so that the wafer surface and potential C〇Pry stai Original Pits) can be highlighted on the surface of the wafer, and then the number of COPs can be detected using a similar measuring instrument of Tencoway; this method provides an easy and reliable wafer quality (or defect) detection method It is known that the measurement of a 2-round surface and the hidden COP number is heavy; this method does not require the use of KLA or similar expensive measuring machines and is more efficient. '' In the process of growing wafers, wafer makers will have defects between the lattices due to external conditions. Generally, wafer makers cut wafers into wafers. Before shipment, it will go through the final polishing before final shipment (final p〇l ish) to smooth the crystal plane, but some cpp benefits can not be removed, please refer to Figure 1, Figure 1 1 is silicon Wafers, 丨 丨 〇 and 1 summer are C0P. The number of these COPs determines the quality of the wafer and affects the yield of integrated circuit manufacturing. If the wafer feed can accurately and quickly detect the number of cop , The product yield can be improved, and the production cost can be reduced; the applicant researched the surface of each new wafer and used KLA to scan out the cop value of each wafer] to about 200 0 ^, these cop values are not available The Tenc0r machine is swept out. The schematic diagram of the cross-section is shown in Figure 1. The crystal surface has the cop that is already shipped. 2. The current COP detection method in the integrated circuit manufacturing process. After the wafer is fed, the KLA machine is used to scan the number of COPs. This method has two major disadvantages: Π) The use of KLA or similar expensive measurement Unit detection 'machine price is higher than Tencor, and the measurement efficiency of KLA is relatively high. (2) Non-interface hidden cdp cannot be detected; please refer to Figure II.

414994

Are silicon wafers, 2 1 0 and 2 1 1 are latent COPs, 2 1 2, 2 1 3, and 2 1 4 are surface COPs. The main purpose of the present invention is to provide a new wafer quality (or defect) inspection method for the semiconductor industry. It mainly firstly cleans, processes, cleans, oxidizes, and etches a whole new wafer to make the wafer surface and potential COP ( Crystai Original Pits) can be highlighted on the wafer surface, and then use Tencor or similar measuring instruments to detect the number of cop; this method provides a simple and reliable method to determine the surface of the wafer and the number of hidden COPs; this The method also does not require the use of KLA or similar heavy duty measuring machines and is more efficient. Brief description of the figure: Figure 1. A schematic diagram of the COP cross-section of a brand-new wafer using the energy measured by KLA; Figure 2. A schematic diagram of the cross-section of a new wafer, the surface COP and hidden COP of the wafer; Invented wafer quality inspection method, wafer cross-section flow chart; Figure 4. This is a scan image of defective particles of 0.15 micrometers or more obtained by using Tencor to scan 1000 angstrom silicon dioxide according to the present invention. Brief description of drawing number: 3 3 ·· Shi Xi wafer 3 4… Shi Xi Xi

310, 311, 312, 313, 314, 315 ... COP

C: \ Patents \ 880237.ptd Page 5 414994 V. Description of the Invention (3) The present invention provides a new wafer quality (or defect) detection method for the semiconductor industry, which includes the following steps: CA) will be a brand new wafer After cleaning, Figure 3 (b) (B) will clean the wafer and grow it with silica dioxide 34, Figure 3 (c) (C) and then etch away the silicon dioxide 34 on the wafer. Figure 3 (D) 0)) Then add silicon dioxide 34. Figure 3 (e) (E) Use Tencor or similar measuring equipment to measure the number of COPs. Figure 4. In step (A), a new wafer is added. For HF and SCI cleaning, because HF and SC1 cleaning are isotropic chemical etching, for silicon materials, the reaction rate on other crystal planes is faster than the < 1 0 0 > crystal plane; therefore, when the wafer surface With COP, while removing particles with HF and SCI, the polycrystalline characteristics of COP will also highlight the defects of (: 0 ?, the number of (: 0?) Increased, see Figure 3 (b), increased COP It is 31 3 and 31 4. In this step, the ratio of the cleaning tank t HF is 49% to 100: 1 (H20: HF), and the ratio of SCI is 1: 1: 5 to 1: 4: 20 (NH3: H202: H20), the temperature in the tank is In the step (B), silicon dioxide is grown in a thermally quenched manner (wet or dry oxygen), wherein the thickness of the silicon dioxide is 40 0 to 50 00 angstroms, and the COP is oxidized during the process. Since the cut surface of Cop is larger than the surface area of other surfaces, it has more oxidized area and accelerates the oxidation rate, and the COP will also cause crystal stress. Lattice stress is driven by oxidative thermal energy. The impurities in the crystal lattice and the phosphorus atoms deposited on the wafer itself will gather at the position of the COP. The impurities and phosphorus atoms play the role of catalyst during the thermal oxidation of silicon dioxide, making dry oxygen or wet oxygen easier.

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C: \ Patents \ 880237.ptd 414994 V. Description of the Invention (4)-Diffusion into the silicon wafer, accelerate the thermal oxidation, and the position of cop is located in the lattice defect, the volume expansion after Sl oxidation or Si0, this Defects are easy to be caused by the surroundings; push and push, and under the action of the above three mechanisms, an oxidized uplift as shown in Figure 3 ^ (C) will be formed. In step (c), use the same etching conditions in step U) to remove silicon dioxide. At this time, more deep COP is formed on the wafer surface. Please refer to Figure 3 (d). 315 is a hidden COP. This step not only highlights The cop on the surface also reveals the hidden cop; in this step, HF removes the silicon dioxide, and SCI etches the silicon wafer, highlighting the number of Cop. '' In step (D), the silicon dioxide is grown to 400 ~ 500 0 0 angstroms using the same aridization conditions in step (C). At this time, more and larger C0P is formed on the wafer surface, please refer to FIG. 3 (e). ). Finally, in step (E), Tencoor_642〇 is used to detect the amount of cop. Please refer to Fig. 4. The thickness of the silicon dioxide in the figure is 1000 Angstroms. The advantages of the present invention are as follows: (0—Newly-injected wafers do not directly perform integrated circuit manufacturing processes. Instead, new wafers are processed after steps (A) (B) (c)). Therefore, the COP measured in this patent is more representative of the COP that affects the yield; a (2) a lower measurement cost can be used to obtain a faster measurement result. In summary, when the present invention is known to have practicality And new sexuality, and

414994 V. Description of the invention C5) The present invention has not been seen in any publications, and it shall comply with the provisions of the Patent Law. However, the above is only one of the preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited by it, that is, all equal changes and modifications made by the scope of the patent application of the present invention shall belong to the patent of the present invention. Covered.

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Claims (1)

414994 VI. Application for Patent Fan Yuan 1.—A kind of semiconductor process wafer quality (or defect) inspection method, which includes the following steps: (A) cleaning a new wafer; (B) cleaning the wafer (C) Etch the silicon dioxide on the wafer again; (D) Add silicon dioxide again; (E) Use Tencor or a similar measuring instrument to measure the number of COPs. 2. The method for inspecting the quality (or defect) of a semiconductor process wafer as described in the first item of the patent application scope, further comprising repeating steps (C) to (D). 3. As described in the first paragraph of the scope of the patent application, the method for inspecting the quality (or defect) of the semiconductor process wafer, the method of cleaning the wafer is HF and SCI ° 4 · As described in the first scope of the patent application, the semiconductor process wafer Quality (or defect) detection method, whose silicon dioxide is formed by thermal oxidation 13 5. If the semiconductor process wafer quality (or defect) detection method described in the first item of the patent scope is requested, the thickness of the silicon dioxide It is 400 ~ 500 Angstroms. 6 · According to the scope of patent application (or defect) inspection method SC, the quality of the semiconductor process wafer described in the first paragraph, the silicon dioxide etching method is HF and ^ Ping u Minhe two semiconductor semiconductor (or defect) inspection Method, the proportion of HF in the cleaning tank is the ratio of the quality age of the round jade, and the temperature in the tank is 414994 VI. Patent Application Range 50 ~ 70 ° C. 8. According to the method for inspecting the quality (or defect) of a semiconductor process wafer as described in the sixth item of the patent application scope, the proportion of HF in the cleaning tank is 49% ~ 100: 1, and the proportion of SCI is 1: 1: 1: 5 ~ 1: 4: 20, the temperature in the tank is 50 ~ 70 degrees Celsius. Page 10 C: \ Patents \ 880237.ptd