TWI274151B - Method and system for wafer defect inspection - Google Patents

Abstract

A semiconductor process is implemented on a wafer. The wafer is scanned simultaneously using bright-field defect inspection tool and a dark-field defect inspection tool. Defect distribution of the wafer obtained by the tools is viewed using an in-line review SEM. A defect inspection operation is implemented on the wafer using the bright-field or dark-field defect inspection tool according to the defect distribution and the catch ratio of killer defect.

Description

1274151_, V. DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a detecting method, and more particularly to a method for detecting a crystal defect. [Prior Art] In the semiconductor manufacturing industry, during wafer processing, such as etching (Etching), developing (Developing), and deposition (Deposition), when the wafer is processed from one process to the next, the relevant The inspection tool checks for defects on the wafer. • The critical dimension design of the cloud in semiconductor manufacturing is decreasing year by year, and the precision and accuracy requirements of wafer inspection are increasing year by year. In order to ensure the quality of semiconductor wafer products and to improve the precision electronics industry technology, it is necessary to provide high-resolution optical equipment for all IC manufacturing / design plants to perform relevant testing procedures, such as post-development inspection (Inspecti〇n After Developing) , hereinafter referred to as ADI ), post-etch inspection (inspecti〇n After Etching, hereinafter referred to as Quality Assurance, QA), quality control (Quality c〇ntr〇1, QC) and other traditional wafer inspection methods The production test procedure is performed using a microscope such as an optical microscope (Optical MiCroscope), a scanning electron microscope (ScaPn = llectron. Microscope, SEM), or a Transmission Electron Microscope (TEM). Optical microscopes, scanning electron microscopes or transmissive electro-microscopes have been widely used in wafer and reticle inspections, including applications in j-panels, optical discs, hard drives, quality control and process management applications, and nanotechnology. Award

0532-A40478TWF(η1); p t.ap-452; ALEXCHEN.p td 1274151 V. Invention description (2) (Nanotechnology) and MEMS (Micro-Electro-Mechanical SyStems, MEMS) applications. For defect detection and analysis, visible light ultraviolet light or laser light is usually used to illuminate the surface of the wafer, and the reflection (Ref lecti〇n) optical 唬' is collected by pattern alignment to detect defects. This detection method is called Bright Field (hereinafter referred to as BF) inspection (Inspecti〇n.). In addition, the surface of the wafer is irradiated with visible light or laser light, and the scattered (s ca t ΐ e r i ng ) optical signals are collected, and the signals are compared to detect defects. This test method is called Dark FieH (hereinafter referred to as swollen). The above-described bright field inspection and dark field inspection are shown in Fig. 1. The DF defect detection tool is characterized by proper sensitivity (Sensi tivi ty), high output, low cost, short scan detection time, and it can detect surface defects of the wafer. The BF defect detection tool features n sensitivity, low throughput, high cost, low sampling rate, and long scan detection time. Even systems or defects that affect yield (such as reticle defects and small three-dimensional (3D) defects). Conventionally, a pattern wafer (p a s t e r n e d w a f e s ) is detected using a BF defect inspection tool, and a particle (p a r t i c 1 e ) defect is detected using a DF defect detection tool. When the detection program is imported, the detection is performed according to different types of wafers (sp 1 i t call nspection). For example, BF defect detection tools are used to detect critical layers, such as ADI and AEI layers, while DF defect detection tools use non-critical layers (n 0 n-critica 1 1 ayer ), such as thin films. Film deposition or non-critical ADI and AEI layers and Chemical Machine Polishing (CMP).

Τ:Α

〇 532-A40478TWF(nl);pt.ap-452;ALEXCHEN.ptd Page 7 1274151 "ΐ, invention description (3) ^ · separate inspection (split inspection) is the main detection strategy in today's 1C manufacturing industry, its purpose It is to properly control wafer inspection, reduce manufacturing costs, and increase production yield. However, there are still some problems with the separate testing process. The detection process separately includes both r-wafer er level sensitivity and "pr〇duction _ sensitivity". "Watt-level sensitivity" is a measure of the defect on the wafer that affects the yield. It requires high sensitivity but does not require too many $. "Production Sensitivity" is a problem of detecting defects in the machine or the process, which requires good sensitivity and a relatively high output. In addition, it is necessary to consider the process development, production capacity, product and trade, and the cost of controlling the holding (C〇st Qwnership, c〇0). In terms of system = R&D, if you want better yield, you need to have higher sensitivity and priority. 'Process capacity and products need to find serious defects and maintain variation control (excursi〇) Nc〇ntr〇i). Manufacturing cost of ownership (C〇0) is considered at the critical point (critical p〇int j circle maximum coverage rate (C〇verage), minimum machine cost, high probability f out, optimized sampling, and most The classification and combination mechanism of Jiahua. Although it has the advantages of the above four, it can not achieve the maximum output, the lowest cost, and the number of samples. The present invention proposes a crystal. The round defect detection method achieves the above object. [Invention] Based on the above object, an embodiment of the present invention discloses a wafer defect inspection.

0532-A40478TWF(nl);pt.ap-452;ALEXCHEN.ptd Page 8 1274151 " One ... '5, invention description (4) j, then work 1 = 曰曰 round a semiconductor process. The defect is obtained by using a visual field defect; the defect distribution obtained by the cloth is aatch Λ (KlUer Defect), and the grasping rate is insufficient. A 1 〇 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 该 该...a θ 暗 视 In the embodiment of the invention: 3:: defect detection operation. Including - defect scanning unit, two:;;; f round defect detection system, its packet. Defect scanning unit utilization, early detection and defect detection single defect detection tools respectively::::= wild defect f measurement tool and - dark field of view after the wafer is scanned + sub- and by a microscopic device to view a t...~ Take;%: two cloth and serious defects (nuer the defect distribution to determine whether to enforce one: 11, 1 〇). The defect handling unit operates according to the field defect detection. Defect ^ Field defect detection operation or a dark vision Field of view defect detection tool = element based on the judgment result to utilize the line-defect detection operation. The present invention is described in the following paragraphs. Only in conjunction with the drawings, the embodiment of the present invention discloses a modified white system, which combines a clear-field wafer defect detection method with a maximum output, minimum cost, and field of view (DF) detection method. The second figure shows the purpose of taking a small number of samples in the embodiment of the present invention. Japanese yen defect detection and traditional inspection

0532- A40478TWF(η 1); p t. ap-452; ALEXCHEN

Ptd Page 9 1274151 Before the finished product is finished, it is necessary to go through a multi-channel, etc., to plate the wafer with a comparison diagram of the method of measurement (5). Wafer process processing, such as etching, development, sinking ... y ... - μ - electric layer, metal layer, buffer layer, insulation layer, etc., and finally obtain the IC finished product. Each time a layer of material is plated on the wafer, a test flow is performed to perform the relevant inspection operation on the layer. As mentioned earlier, BF defect detection tools are used to detect critical layers such as ADI and germanium layers, while DF defect detection tools are used to measure non-critical layers such as thin film deposition or non-critical AD I and ΑΕ I layers and chemical machinery. Grinding (CMP). Referring to Fig. 2, it shows a material to be plated on a wafer layer (assuming a layer of Α~G). In the traditional wafer inspection method, the a, B, and 4 layers are the key layers. Therefore, the BF detection tool is used for the defect detection, and the D, F, and G layers are non-critical layers, so the DF inspection tool is used and the = Measured by the description:: The detection process is multi-line detection on the wafer "including the = f line, and a variety of other problems. : = The characteristics of the DF defect detection tool is appropriate

High cost, high sampling rate, and sampling anti-banking time sensitivity and DF defect detection workers. BF is described as a bucket, and has its advantages and disadvantages, but the invention 訾 # ^ = = = : The superiority of the ::::; to determine the current wafer layer should be two; = 丄 Λ Λ Λ Β The Ε layer (key layer) does not only use the eu^ detection aid to perform defect detection, but the same day) does not use the BF defect detector. Hereinafter, the method for detecting the wafer defect of each of the two yokes of the present invention will be described: 0532- A40478TW(nl); pt.ap-452: ALEXCHEN.ptd Page 10 1274151 V. Description of invention (6) Process. The figure is a step view of the step of the wafer defect detecting method of the embodiment of the present invention. The DF defect detecting method for wafer defect inspection in the embodiment of the present invention is described by way of example, and therefore, the method for detecting defects in the FF is not described herein. Defect detection procedure (in the case of Taisu Ris Α γ t ^ (AD" in the case of the development of the post-development (ADI) and the post-mortem inspection (AEI) as an example)

The Uisi full defect detection tool scans the wafer-pass (step 丄, S4) ’ and then examines the wafer defect distribution by the electron microscope (steps S3 and 35). If a serious defect step is found on the wafer.檐h ώΑ 所 na na na na DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF Otherwise, step S9 is performed. The right serious defect capture rate does not exceed 2 〇%. The wafer performs the detection operation (step S9). (4) Talk about the defect detection tool pair ► Next, if the serious defect capture rate exceeds whether the heavy defect is distributed in a cluster manner (cl 0 then accepts the rigorous r + 酹Qin, ... ^ luster distribution) S12 -Li right % executes the step SU 'otherwise the execution steps are strictly enforced on the broad circle: the second Λ方牛式1 /, confrontation执Because the detection operation is performed (step S11). If the serious defect is not a bundle

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Korea

1274151 V. Description of invention (7) _ Set distribution, then judge whether the catch rate of serious defects using DF exceeds 40% of the serious defect capture rate of profit_F: = j = (Step ^ ^田所If the step % is executed, the BF defect detection worker is used and the round _ sheep does not exceed 40 S (1). If the serious defect is caught, the inspection is performed ((4) Tools Performing a detection operation on the wafer (step s丨4), 1 Insufficient intent to inspect the fourth wafer defect inspection of the embodiment of FIG. 2, the wafer defect detection system 400 of the example of the invention includes a defect|二, - Defect processing unit 43 ° and - Defect detection unit (# # ^ ^ ^ ^ ^ ^ ) and Yu Hai after the inspection (A £ I) as an example) Gate / Element 410 using BF_F defect detection and ^After the binding, the wafer defects obtained after scanning a single micro-mirror inspection scan, and the defect processing unit 430 determine whether there is a serious defect. If no serious defects are found on the circle, 丨^ defects, Then suppress::? Perform the second detection operation. If in the crystal (four) description, then judge the use of the defect detection tool and sweep Whether the rate exceeds 2% of the crawling defect inspection m:: the grab rate. If the critical defect capture rate wafer performs the detection operation, use the W-miss detection tool for the next 'if the serious defect capture rate exceeds 2〇 %, then the defect processing single I face page 12 0532-A40478TWF (nl); pt.ap-452; ALEXCHEN, -1274151 five, invention description (8) ______ ^ yuan 4 3 0 then determine whether the serious defect is The cluster mode distribution, the defect detection list " yuan 4 & = cloth. If severely missing, then the defect processing unit 430 then judges the use of the DFm set method to extract the serious defects of the grab rate is, the 曰 loose tool sweep scan The resulting severe defect capture rate of 4 ', two $ two defect detection tool detection operation 'otherwise, the defect detection tool for the crystal two · the wafer defect If defect detection scan of the embodiment of the present invention, and respectively adhere to the implementation of BF and DF defect detection scan optimal control, such as BF defect detection, which can reduce the number of samples with more samples for scanning, and can minimize the risk of variation. The trap detection method performs different sampling on some wafer layers. rate Other wafer layers can reduce the cost by having high sensitivity to the wafer layer only for the cost of ownership (C〇〇). In addition, it is possible to simultaneously reduce the sampling rate due to the embodiment of the invention. The semiconductor manufacturing industry is taken as an example for description, and is mainly applied to a 3 mm-thick wafer produced by a 12-inch fab. In addition, the embodiment of the present invention is mainly applied to post-development inspection (adi) ) and the post-mortem inspection (AEI) process. However, the above application is not intended to limit the present invention, and any similar semiconductor process can be implemented by the wafer defect detecting method of the embodiment of the present invention. Although the present invention has been described above by way of a preferred embodiment, it is not intended to limit the present invention, and those skilled in the art, without departing from the spirit of the invention

1274151

0532-A40478TWF(nl);pt.ap-452;ALEXCHEN.ptd Page 14 1274151_ 'Simple description of the diagram [Simplified illustration] Figure 1A shows a schematic diagram of the bright field inspection. Figure 1 B shows a schematic of a dark field examination. Fig. 2 is a view showing a comparison of wafer defect detection and conventional detection methods in the embodiment of the present invention. Fig. 3 is a flow chart showing the steps of the wafer defect detecting method of the embodiment of the present invention. Fig. 4 is a view showing the display of the wafer defect detecting system of the embodiment of the present invention. i [Major component symbol description] 400~ Wafer defect detection system 4 1 0~ defect scanning unit 430~ defect processing unit 4 5 0~ defect detection unit

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Claims (1)

1274151 '6. The method for detecting defects in the patent application scope includes the following steps: performing a semiconductor process on a daily basis; scanning the 曰曰曰1] using a clear field of view @^丨; , u "4 - dark field defect detection tool And using the microscopy device to examine the defect distribution obtained after scanning the wafer; according to the defect distribution and the seriousness of the rate (Catch, (KlUer Defect), the detection of the defects in the bright field is extremely poor _" 2::ΐ: The tool performs the defect-detection operation on the wafer,... In-gas Ϊ = The wafer defect detection method described in item 1 includes the following steps: The trap detection tool performs the defect detection operation. If there is a serious defect on the wafer, and if the defect is f ί _ = II ^ 厫, the dark field defect detection is used, and the defect detection operation is performed on the day = Bean 3 · Please refer to the wafer defect detecting method described in the second aspect of the patent, wherein the determination is performed by the defect detecting tool to perform the following steps: If you have a serious defect on the right 5H wafer, Determining whether the grab rate of the serious defect obtained by scanning the DF defect detecting work scoop exceeds the serious defect grab rate obtained by scanning the BF defect detecting tool by a predetermined ratio, and if the grab rate of the serious defect is not When the first predetermined ratio is exceeded, the defect detection operation is performed on the wafer by using the bright field defect detecting tool. 4 · The wafer defect detecting method according to claim 3, 0532-A40478TWF(nl);pt.ap-452;ALEXCHEN.ptd Page 16 The %疋 ratio is 20%. b · If the scope of the patent application is included;, ★ The defect detection method for the defect inspection process, including the following steps·········································································· If the rate exceeds the first predetermined 疋 疋 疋 疋 - - 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛 丛The next day, Si performs the defect inspection and the dark field is lacking. 6. If the patent application is used, the test is performed. J. Among them, the wafer defects described in the 5 poverty-stricken brothers are determined, and the target is The defect inspection worker and the detection method include the following steps: , /, performing the defect detection operation, if the serious defect is not LV # | & the defect detection worker is swiping the ^ household ^ the cluster mode is divided into < cloth, then The catch rate of the serious defects obtained by the use of the BF defect 烚 '目I is: Ϊ F example; the serious defect of the field is captured by a flute with 4 brothers 2 is determined to be more than the serious defect > vt _ Bright field defect inspection: J does not exceed: the second established ratio, then profit And performing the defect detection operation on the wafer. The _dark===take rate exceeds the predetermined ratio of the fth, and the defect detection is performed on the wafer by using 7··申申直直4丨#/ Operation. The wafer defect detector described in item 6 of the mid-month range, ...nur wafer defect detection system, including the missing scanning unit, is used to utilize a bright field defect detector ~ in the '§ Haidi 2 has a predetermined ratio of 4〇%. Method, Ο. Θ fsl J^L· r**. 1274151 ΖDark field of view defect detection tool scans, wafers, and scans the wafer by micro-coating a defect distribution unit; a defect processing unit configured to determine whether to perform a bright field defect detecting operation or a dark field defect detecting operation according to the defect distribution; and a defect detecting unit to use the light according to the determining result The field of view defect detecting tool or the dark field defect detecting tool performs a defect detecting operation on the wafer. 9 . The wafer defect detecting system according to claim 8 , wherein the defect processing unit distributes according to the defect Judge the crystal Whether there is a serious defect on the wafer, if there is no serious defect on the wafer, the defect detection=the defect detection operation is performed on the wafer by using the dark field defect detection tool. The invention is as described in claim 9 A wafer defect inspection system, wherein 'if there is a serious defect on the wafer, the defect processing unit judges whether the grab rate of the serious defect obtained by the DF defect detecting tool is excessive, and the BF defect detecting tool scans the serious The defect capture rate is 2 〇σ ^ i and if the capture rate of the severe defect does not exceed 20%, the defect detection unit performs the defect on the wafer using the bright field defect detection tool: the measurement operation. • 11 · If the wafer defect detection system described in item 10 of the patent application scope is 2, 'If the catch rate of the serious defect exceeds 2%, then the defect is determined by the unit to determine whether the serious defect is in a cluster mode. The distribution, and if the severe defect is distributed in the cluster, the defect detecting unit performs the defect detecting operation on the wafer using the dark field defect detecting tool. 12741^1 VI. Application for Patent Scope 12. If the patented scope is not the case, the serious defect is not determined by the fading defect detection system processing unit using the DF defect detection f-type distribution. Then, whether the defect capture rate exceeds 40% of the serious defect trapping rate obtained by using the BF defect ^ two scans, if the serious shortage, the tool scan is seriously lacking " the Hai defect detection unit uses the bright field If the defect=fetch rate does not exceed 40%, the defect detection operation, and if the severity=second test tool performs %' on the wafer, the defect detecting unit performs the defect detection by using the dark-view C rate exceeding the 40-circle operating. The sub-feature detection tool is a storage medium for storing data, and the storage method includes a plurality of code codes for loading into the on-site electrical system to perform a wafer defect from the column step: |曰a method for detecting, comprising: performing a semiconductor process on a wafer; an eight-dimensional 2 U-field defect detecting tool and a dark-field defect detecting tool: % drawing the wafer; 8. using a micro-device to view the wafer a defect distribution obtained after scanning; and 'determining a defect detection operation on the wafer by the bright field defect detecting tool or the dark field defect detecting tool according to the defect distribution. The storage medium of claim 3, wherein the determining the defect detecting operation by the defect detecting tool further comprises the step of: determining whether there is a serious defect on the wafer according to the defect distribution; And 0532-A40478TWF(nl); pt.ap-452; ALEXCHEN.ptd Page 19^274151 VI. Patent Scope If there is no serious tool on the wafer, the defect inspection operation is performed on the wafer = use the dark field defect Detection 1 5 · If the scope of patent application is the first! 4 Decide to use the storage medium described in the defect detector 1 in which: Step A: The detection operation includes the following: If the wafer has serious defects in the wafer, the defect detection worker is used. The serious shortage of the tool scan is over, that is, the defect detection rate is not exceeded. (4) The first predetermined ratio is the storage medium mentioned in item 15 of the profit-making scope, wherein the ratio of the 罘 疋 is 2 0%. 17. If the storage medium described in claim 15 of the patent application, in the basin, the defect detecting tool performs the defect detecting operation to further include the following strict = : = = = first:; The severe defects are distributed in the clustering manner, and the > trap detection tool performs the defect detecting operation on the wafer. Λ 9 ^野缺1 8. As in the storage medium described in claim 17 of the patent application, it is decided to perform the defect detection operation with the defect detection tool, 'step: and include the following if the serious defect is not According to the clustering method, the grab rate θ of the serious defect obtained by the defect detection tool scan is not exceeded by the Df. 0532-A40478TWF(nl);pt.ap-452;ALEXCHEN.ptd Page 201274151 ----^^ VI. Application for patent scope BF defect inspection for financial workers - '~"' example; The serious defect capture rate is the same as the stone 'Φ' Ζ-L, with the day and month visual field defect = the grab rate does not exceed the second predetermined ratio, then the profit and the double, the tool executes on the wafer The defect detecting operation; if the blanking rate exceeds the second predetermined (four), the defect detecting operation is performed on the wafer by using the lg^曰h measuring tool. ^ The storage medium as described in claim 18, wherein the second predetermined ratio is 40%. 0532-A40478TWF(nl);pt.ap-452;ALEXCHEN.ptd第21页