TWI230983B - Method of forming patterned photoresist layer and equipment for forming the same - Google Patents

Abstract

A method of forming a patterned photoresist layer aligned with a predetermined layer is provided. The method comprises steps as follow: (a) forming a photoresist layer on a substrate; (b) exposing the photoresist layer; (c) measuring an overlay offset between the exposed portion of the photoresist layer and the predetermined layer; (d) judging whether the exposed portion of the photoresist layer is proper; and (e) performing a developing process, when the exposed portion of the photoresist layer is proper. An equipment for forming a patterned photoresist layer is also provided. The equipment using the method mentioned above can feedback a real-time measurement result to reduce cycle time and rework time.

Description

1230983 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a method for forming a patterned photoresist layer and a manufacturing machine thereof, and in particular to a method capable of real-time (rea 1-time) Method for forming patterned photoresist layer with overlapping measurement results and manufacturing machine thereof. [Previous technology] With the progress of the semiconductor industry, many high-performance semiconductor components or integrated circuits have been developed successively. High-performance semiconductor components or integrated circuits usually contain millions of components. Such as transistors, capacitors, resistors, etc. As semiconductor devices or integrated circuits continue to expand their performance, the degree of accumulation of the layout of each component needs to be continuously improved. In other words, when the layout area is limited, it is necessary to increase the number of layers in the circuit layout. Or further reduce the critical dimension (Critical Dimension, CD) ° With the increasing accumulation of the layout of each element, the alignment issue (a 1 ignmentissue) between the film layers becomes very important. For example, when mis-alignment occurs between a patterned wire layer and a plug in a semiconductor device or a integrated circuit, the overall performance of the semiconductor device or the integrated circuit is greatly improved. Drop, and even inoperable. In addition to the problem of misalignment between the wire layers, ion doping and ion implantation will also have misalignment problems, and these misalignment problems will also cause semiconductor components. Or the overall performance of the integrated circuit is greatly reduced. In general semiconductor devices or integrated circuits, the pattern of the patterned film layer and the area of ion doping or ion implantation are performed by lithography (exposure

12973twf.ptd Page 8 1230983 V. Description of the invention (2) The patterned photoresist layer formed by photo / development) is defined, so the patterned photoresist layer must be subjected to overlay measurement after exposure / development measurement) in order to determine whether there is a misalignment. FIG. 1 is a flowchart of a conventional patterned photoresist layer. Referring to FIG. 1, a wafer is first provided, and a photoresist layer is formed on the wafer by coating (S100), and then the photoresist layer is exposed by an exposure device (S 1 1 0) and developed (S 1 1 2 0) to form a patterned photoresist layer with a specific pattern. In order to ensure that the specific pattern of the patterned photoresist layer can be aligned with other film layers on the wafer, an overlay error measuring device (y) is usually used to measure the pattern. The photoresist layer and other film layers are measured. The overlap error between them (S130), and it is judged whether the overlap error is appropriate (S 1 4 0). In other words, the overlap error measured by the overlap error measuring device can determine whether the specific pattern of the patterned photoresist layer is aligned with other film layers on the wafer. When the overlap error is within a tolerance range, the next process step is performed (S150). Conversely, when the overlap error is too large, the patterned photoresist layer on the wafer is removed for rework, and a control signal is feedback to the exposure device (S 1 60) through the overlap error measurement device to adjust Photoresist layer exposure position. Generally speaking, the overlap error amount j used in the conventional technology is usually an ACML device, but this overlap error measurement device and the above manufacturing process still have the following disadvantages: 1. In the manufacturing process of the conventional technology, the photoresist After the layer system is exposed / developed, the overlap error is measured by the ACML device. This process sequence

12973twf.ptd Page 9 1230983 V. Description of the invention (3) Often the developer is wasted. 2. The ACML device cannot measure the overlap error in real time, and feedback the control signal to the exposure device in real time. When the feedback control signal indicates that the exposure position needs to be adjusted, the exposure equipment may have resisted the photoresist on many subsequent wafers. Layers are exposed, and these wafers must be reworked. 3. Because ACML devices are very expensive, they often increase process costs. 4. To use the ACML device for overlapping error measurement, an overlay measurement mark must be made on the wafer's scribe lane area (scribe 1 anearea), but these overlap measurement marks make the scribe lane area impossible to further Zoom out. [Summary of the Invention] Therefore, the object of the present invention is to provide a method for forming a patterned photoresist layer that can instantly feedback ^ overlapping measurement results, so as to effectively shorten the manufacturing time (cyc 1 etime). One objective is to provide a manufacturing machine capable of feedbacking the measurement results of the patterned photoresist layer in real time, so as to shorten the manufacturing time. To achieve the above object, the present invention provides a method for forming a patterned photoresist layer, which is suitable for forming a patterned photoresist layer aligned with a film layer. The method for forming the patterned photoresist layer includes the following steps: (a ) Forming a photoresist layer on a substrate; (b) exposing the photoresist layer; (c) measuring an overlay offset between the exposure position of the photoresist layer and the film layer; (d) ) Determine whether the exposure position of the photoresist layer is appropriate based on the overlap error; and (e) develop the photoresist layer when the exposure position of the photoresist layer is appropriate.

12973twf.ptd 1 10 pages 1230983 V. Description of the invention (4) When the exposure position of the photoresist layer is inappropriate, for example, the steps (0) and steps (a) to (d) of the photoresist layer can be repeated in order. Once, each of which adjusts the exposure position of the photoresist layer according to the overlap error measured in the previous step (c) until the exposure position of the photoresist layer is judged to be appropriate by step (d). 0 According to an embodiment of the present invention As mentioned above, the above-mentioned photoresist layer will form a virtual pattern after exposure, and the measurement of the overlap error is, for example, providing a laser light source, and then scanning the virtual pattern by the laser light source to determine the photoresist layer. Whether the exposure position is appropriate. To achieve the above object, the present invention provides a method for forming a patterned photoresist layer, which is suitable for forming a patterned photoresist layer aligned with a film layer. The method for forming the patterned photoresist layer includes The following steps: (a) forming a photoresist layer on a substrate; (b) providing an exposure / overlap measurement device, and exposing the photoresist layer by the exposure / overlap measurement device to perform photoresist A void Virtual image; (c) measuring an overlap error between the virtual pattern and the film layer by an exposure / overlap measurement device; (d) comparing the overlap error with a preset value; and ( e) When the overlap error is less than the preset value, the photoresist layer is developed. When the overlap error is greater than the preset value, for example, the "step (f)" and step (a) of removing the photoresist layer may be sequentially repeated ~ (D) at least once, each of which adjusts the exposure position of the photoresist layer according to the overlap error measured in the previous step (c), until step (d) compares that the overlap error is less than a preset value. Among them, The method for adjusting the exposure position of the photoresist layer according to the overlap error, for example, before step (f), feedback a control signal to the exposure / repetition according to the overlap error.

12973twf.ptd Page 11 1230983 V. Description of the invention (5) '' Overlaid measurement setting, so that it can adjust the light a layer according to the embodiment of the present invention, as described above using exposure / re-entry measurement ^ A laser light source is provided, and the virtual pattern described by the laser light source 2 is used to scan and scan "" to determine whether the position of the virtual pattern is appropriate. For the purpose of the present invention, a manufacturing port for a patterned photoresist layer is provided. @ = Formed on a substrate—patterned photoresist layer, and patterned: ίMaterial's layer is aligned 'The manufacturing machine for patterned photoresist layer, for example, f consists of a photoresist coating device, a It consists of exposure / overlap measurement equipment, a developing device, and a substrate transfer device. In the middle, the photoresist coating equipment is used to coat a photoresist layer on the substrate; the exposure / overlap measurement equipment is Exposure of the photoresist layer to form a virtual pattern in the photoresist layer, and the exposure / overlap measurement device is used to measure an overlap error between the virtual pattern and the film layer in real time; the developing device is suitable for photoresist Layer development; and the substrate transfer equipment is connected to the photoresist coating equipment Between the exposure / overlap measurement device and the developing device, the substrate is transferred between the photoresist coating device, the exposure / overlap measurement device, and the developing device. According to the embodiment of the present invention, the patterned light described above The manufacturing equipment of the resist layer further includes, for example, a photoresist removal device, and the photoresist removal device is connected to an exposure / overlap measurement device by a substrate transfer device. In addition, the photoresist removal device is, for example, a system The substrate transfer device is connected to the photoresist coating device. According to the embodiment of the present invention, the substrate transfer device described above selectively transfers the substrate to the photoresist removal device or the developer according to the overlap error.

12973twf.ptd Page 12 1230983_ 5. Description of the invention (6) In the equipment. In other words, when the overlap error is too large, the substrate transfer device will transfer the substrate to the photoresist removal device for rework; when the overlap error is within the tolerance range, the substrate transfer device will transfer the substrate to The developing device performs a developing action. According to the embodiment of the present invention, the above-mentioned exposure / overlap measurement device is composed of, for example, a photoresist exposure module and an overlay measurement module. The photoresist exposure module is suitable for forming a virtual pattern in the photoresist layer, and the overlap measurement module is suitable for detecting the overlap error between the virtual pattern and the film layer to be aligned in real time, and feedback based on the overlap error. A control signal to the photoresist exposure module. According to the embodiment of the present invention, the above-mentioned photoresist exposure module is composed of, for example, an exposure light source and a photomask, wherein the exposure light source is disposed above the substrate, and the photomask is disposed, for example, on the exposure light source and Between substrates. In addition, the overlapping measurement module is composed of, for example, a laser light source, a signal acquisition element, and a signal feedback element. The laser light source is for example scanning a virtual pattern, and the signal acquisition element is for example scanning. The latter represents a test signal of one of the overlap errors, and the signal feedback element generates a control signal according to the test signal, for example, and feeds back the control signal to the photoresist exposure module. Since the present invention performs overlay measurement after the photoresist layer is exposed and before development, the overlay measurement result can be fed back immediately to effectively avoid unnecessary rework actions. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes specific embodiments with reference to the accompanying drawings and describes them in detail.

12973twf.ptd Page 13 1230983 V. Description of Invention (7) The following is explained. [Embodiment] In view of the shortcomings of the conventional technology, the present invention mainly integrates the overlap measurement module and the exposure module, so that the overlap measurement is performed after the exposure process and before the development process, so as to achieve real-time different control. Purpose, this method will more effectively reduce the manufacturing time and rework time of the patterned photoresist layer on each wafer. FIG. 2 is a flowchart of forming a patterned photoresist layer according to a preferred embodiment of the present invention. Referring to FIG. 2, a substrate is first provided. For example, some substrates have been formed on the substrate. The substrates used in this embodiment are, for example, wafers used for manufacturing semiconductor elements or integrated circuits, glass substrates, quartz substrates, plastic substrates, silicon substrates used for manufacturing display panels, and printed circuit boards. Plastic substrate, ceramic substrate, etc. Next, a photoresist layer is formed on the substrate (S200), and then the photoresist layer is exposed, and an overlap error (S2 1 0) between the exposure position of the photoresist layer and the film layer is measured. In this embodiment, for example, an exposure / overlap measurement device is provided, and the photoresist layer is exposed by the exposure / overlap measurement device, so as to form a virtual pattern in the photoresist layer. The overlap measurement device measures an overlap error between the virtual pattern and the film layer. It is worth noting that the patterned photoresist layer to be formed in this embodiment is, for example, used to define the pattern position of each film layer in a semiconductor element or integrated circuit, such as a pattern of a wire layer, an opening in a dielectric layer, a conductor Formation of plugs, ion-doped regions, and the like. After the patterned photoresist layer is formed, for example

12973twf.ptd Page 14 1230983 V. Description of the invention (8) The thin film etching process, ion doping process, ion implantation process, or thin film deposition process can be followed. However, in addition to the above, the method for forming the patterned photoresist layer of the present invention can also be applied to other situations where precise alignment is required. Anyone skilled in this technology can make appropriate changes, but the changes should still belong to The scope of the invention. Next, it is judged whether the exposure position of the photoresist layer is appropriate based on the overlap error (S 2 2 0). In other words, in this embodiment, for example, the measured overlap error can be compared with a preset value to determine whether the exposure position of the photoresist layer is appropriate. When the overlap error is less than the preset value, which means that the overlap error is still within a tolerable range, the photoresist layer is developed (S 2 3 0) to form a patterned photoresist layer, and then the patterned light The resist layer is a thin film etching, ion doping, ion implantation, or thin film deposition process for the mask (S240) to form a precisely patterned film layer or ion doped region. Conversely, when the overlap error is greater than a preset value, for example, a control signal is first fed back to the exposure / overlap measurement device (S 2 50) according to the overlap error to adjust the exposure conditions, and then the exposed light is removed. And then repeat the steps (S 2 0 0) to (S 2 2 0). When the overlap error is less than the preset value, the photoresist layer is developed (S230); and when the exposure position of the photoresist layer is still inappropriate, steps (S250) and steps (S200) to (S200) are sequentially repeated again. 2 2 0) at least once until the exposure position of the photoresist layer is appropriate, and then develop (S 2 3 0). FIG. 3 is a schematic structural diagram of a manufacturing machine for patterning a photoresist layer according to a preferred embodiment of the present invention. Referring to FIG. 3, the manufacturing machine 3 0 of the patterned photoresist layer of this embodiment is, for example, a photoresist coating device 4

12973twf.ptd Page 15 1230983 V. Description of the invention (9) Light / overlap measuring equipment 5 0 0, a developing device 6 0 0, and a substrate conveying device 7 0 0. Among them, the photoresist coating device 400 is used to coat a photoresist layer on a substrate; the exposure / overlay measurement device 500 is used to expose the photoresist layer to form a dummy in the photoresist layer. Pattern, and the exposure / overlay measuring device 500 is used to measure an overlap error between the virtual pattern and the film layer in real time; the developing device 600 is suitable for developing the photoresist layer; and the substrate conveying device 7 0 0 is connected between photoresist coating equipment 400, exposure / overlap measuring equipment 5000 and developing device 600, to transfer the substrate to photoresist coating equipment 400, exposure / overlap Measuring equipment between 500 and developing equipment 600. In this embodiment, the manufacturing machine 300 for the patterned photoresist layer further includes, for example, a photoresist removal device 800, and the photoresist removal device 800 is, for example, a substrate transfer device 700. Connected to exposure / overlap measurement equipment 500. In addition, the photoresist removal device 800 is connected to the photoresist coating device 400 by, for example, a substrate transfer device 700. In this embodiment, the substrate transfer device 700 selectively transfers the substrate to the photoresist removal device 800 or the developing device 600 according to the overlap error. In other words, 'When the overlap error is too large, the substrate transfer device 700 will transfer the substrate to the photoresist removal device 800 for rework. Conversely, when the overlap error is within the tolerance range, the substrate transfer device 700 will transfer the substrate to the developing device 600 for development operation. FIG. 4 is a schematic diagram showing the structure of the exposure / overlap testing device in FIG. 3. Referring to FIG. 4, the exposure / overlap measurement device 500 of this embodiment is composed of, for example, an overlay measurement module 5 10 and a photoresist exposure module 5 2 0. The photoresist exposure module 520 is adapted to form a virtual pattern in the photoresist layer, and

12973twf.ptd Page 16 1230983 V. Description of the invention (10) The weight measurement module 5 1 0 is suitable for detecting the overlap error between the virtual pattern and the film layer to be aligned in real time, and feedback one based on the overlap error. Control signal to photoresist exposure module 5 2 0. Please also refer to FIG. 4 'The overlapping measurement module 5 of this embodiment is composed of a laser light source 5 1 2, a signal acquisition element 5 1 4 and a signal feedback element 5 1 6', among which The laser light source 5 1 2 scans the virtual pattern to determine whether the position of the virtual pattern is appropriate, and the signal acquisition element 5 j 4 captures a test signal SMEASUREMENT, which represents one of the overlapping errors after scanning, and the signal is fed back. The element 516 generates, for example, a control signal SC0NTR0L according to the test signal SMEASUREMENT, and feeds back the control signal SC0NTR0L to the photoresist exposure module 520 to make it adjust the exposure conditions. In addition, the above-mentioned photoresist exposure module 5 2 0 is composed of, for example, an exposure light source 5 2 2 and a mask 5 2 4. The exposure light source 5 2 2 is, for example, disposed above a substrate, and the mask 524 is, for example, It is arranged between the exposure light source 522 and the substrate. In summary, the method for forming a patterned photoresist layer and the manufacturing machine thereof of the present invention have at least the following advantages 1. The exposure process and the overlapping measurement action of the present invention are performed in the same equipment, so it can be effectively shortened Time of manufacture. 2 · Since the photoresist layer on the substrate is measured for overlap error immediately after exposure, and the measurement of overlap error is completed before the development process, the measured overlap error can be immediately fed back to the exposure module ' To avoid unnecessary heavy work. 3. Due to the overlap error of the photoresist layer on the substrate immediately after exposure

12973twf.ptd Page 17 1230983_ V. Description of the invention (11) The measurement, and the measurement of the overlap error is completed before the development process. The reliability of the measurement result of the overlap error is not affected by the development process parameters. Will be greatly improved. 4. The exposure / overlap measurement equipment used in the present invention is sufficient to replace the traditional ACML equipment, so the expensive cost of using the ACML equipment can be eliminated. 5. Since the exposure / overlap measurement equipment maintains the scanning accuracy of the original stepper (s c a η n e r), it will be more accurate in the measurement of overlap errors, which is in line with the requirements of the next generation process. 6. The present invention only needs to slightly modify the overlapping marks on the substrate to obtain a patterned photoresist layer with a precise exposure position, and in some cases, it is not even necessary to redesign the overlapping marks on the substrate, so Will cause a cost burden. 7. The invention can reduce the scribe line area on the wafer to increase the total die number on each wafer. Although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application.

12973twf.ptd Page 18 1230983_ Brief description of the drawings Figure 1 shows a conventional process for forming a patterned photoresist layer. FIG. 2 is a flowchart of forming a patterned photoresist layer according to a preferred embodiment of the present invention. FIG. 3 is a schematic structural diagram of a manufacturing machine for patterning a photoresist layer according to a preferred embodiment of the present invention. FIG. 4 is a schematic structural diagram of an exposure / overlap testing device in FIG. 3. [Explanation of diagrammatic symbols] S1 00 Form photoresist layer S1 1 0 Exposure S1 20 Development S1 30 Overlap error measurement S140 Determine whether the overlap error is appropriate S1 50 Next process step S1 60 Rework 丨 & Control signal feedback S200 Form light Resistive layer S210 Exposure & overlap error measurement S220 Determine whether the overlap error is appropriate S230 Development S240 Next _ one process step S250 Heavy industry 丨 & control signal feedback 3 0 0: Manufacturing machine for patterned photoresist layer 4 0 0 · Photoresist coating equipment 5 0 0: exposure / overlap testing equipment

12973twf.ptd Page 19 1230983

Brief description of the drawing 5 10 Overlapping measurement module 5 12 Laser light source 5 14 Signal acquisition element 5 16 Signal feedback element 520 Photoresist exposure module 522 Exposure light source 524 Photomask 600 Development equipment 700 Substrate transfer equipment 800 Light Blocking device 12973twf.ptd Page 20

Claims (1)

1230983 VI. Application for patent scope 1. A method for forming a patterned photoresist layer, which is suitable for forming a patterned photoresist layer aligned with a film layer. The method for forming a photoresist layer includes the following steps: ( a) forming a photoresist layer on a substrate; (b) exposing the photoresist layer; '(c) measuring an overlap error between the exposure position of the photoresist layer and the film layer; (d) ) Judging whether the exposure position of the photoresist layer is appropriate according to the overlap error; and (e) developing the photoresist layer when the exposure position of the photoresist layer is appropriate. 2. The method for forming a patterned photoresist layer as described in item 1 of the scope of patent application, wherein when the exposure position of the photoresist layer is inappropriate, the method further includes the following steps before step (e): One step (f) "and steps (a) to (d) of removing the photoresist layer, at least once, each of which adjusts the exposure position of the photoresist layer according to the overlap error measured in the previous step (c) until The exposure position of the photoresist layer is judged to be appropriate through step (d). 3. The method for forming a patterned photoresist layer as described in item 1 of the patent application scope, wherein the photoresist layer will form a virtual pattern after exposure, and the measurement of the overlap error includes the following steps: providing a laser A light source; and scanning the virtual pattern by the laser light source to determine whether the exposure position of the photoresist layer is appropriate. 12973twf.ptd Page 21 1230983 6. Application for patent scope 4. A method for forming a patterned photoresist layer, suitable for forming a patterned photoresist layer aligned with a film layer, and a method for forming the patterned photoresist layer It includes the following steps: (a) forming a photoresist layer on a substrate; (b) providing an exposure / overlap measurement device, and exposing the photoresist layer by the exposure / overlap measurement device, so that A dummy pattern is formed in the photoresist layer; (c) an overlap error between the dummy pattern and the film layer is measured by the exposure / overlap measurement device; (d) the overlap error and a preset Value comparison; and (e) when the overlap error is less than the preset value, developing the photoresist layer. 5. The method for forming a patterned photoresist layer as described in item 4 of the scope of patent application, wherein when the overlapping error is greater than the preset value, the method further includes the following steps before step (e): One step (f) "and steps (a) to (d) of removing the photoresist layer, at least once, each of which adjusts the exposure position of the photoresist layer according to the overlap error measured in the previous step (c) until Step (d) compares until the overlap error is less than the preset value. 6. The method for forming a patterned photoresist layer according to item 4 of the scope of patent application, wherein the method of adjusting the exposure position of the photoresist layer according to the overlap error includes: feedback a control signal to the exposure / overlap according to the overlap error. Measure the device to adjust the exposure position of the photoresist layer. 12973twf.ptd Page 22 1230983 6. Application for patent scope 7. The method for forming a patterned photoresist layer as described in item 4 of the scope of patent application, wherein the overlap measurement includes providing a thunder using the exposure / overlap measurement equipment The light source is scanned, and the virtual pattern is scanned by the laser light source to determine whether the position of the virtual pattern is appropriate. 8. A manufacturing machine for a patterned photoresist layer, adapted to form a patterned photoresist layer on a substrate, and align the patterned photoresist layer with a film layer on the substrate. The manufacturing machine of the patterned photoresist layer includes: a photoresist coating device for coating a photoresist layer on the substrate; and an exposure / overlap measuring device for exposing the photoresist layer to A virtual pattern is formed in the photoresist layer, and the exposure / overlap measurement device measures an overlap error between the virtual pattern and the film layer in real time; a developing device is used to develop the photoresist layer; And a substrate transfer device connected between the photoresist coating device, the exposure / overlap measurement device, and the developing device. 9 · The manufacturing machine for the patterned photoresist layer described in item 8 of the scope of patent application, further comprising a photoresist removal device, which is connected with the exposure / Overlapping measurement device connection. 10. The machine for manufacturing a patterned photoresist layer according to item 9 of the scope of the patent application, wherein the photoresist removal device is connected to the photoresist coating device through the substrate transfer device. 1 1. The manufacturing machine for the patterned photoresist layer according to item 9 of the scope of the patent application, wherein the substrate transfer device selectively transfers the substrate to the photoresist removal device according to the overlap error. And one of the developing devices 12973twf.ptd Page 23 1230983__ VI. Patent application scope 1 2. The manufacturing machine for the patterned photoresist layer described in item 8 of the patent application scope, wherein the exposure / overlap measurement equipment includes: a photoresist exposure mode Group, which forms the virtual pattern in the photoresist layer; and an overlap measurement module, which detects an overlap error between the virtual pattern and the film layer in real time, and feedbacks a control signal to The exposure / overlap measurement device. 1 3. The manufacturing machine for a patterned photoresist layer as described in item 12 of the scope of the patent application, wherein the photoresist exposure module includes: an exposure light source disposed above the substrate; and a photomask 5 Disposed between the exposure light source and the substrate. 1 4. The manufacturing machine for a patterned photoresist layer as described in item 12 of the scope of the patent application, wherein the overlapping measurement module includes: a laser light source that scans the virtual pattern; a signal acquisition The component is a test signal representing the overlap error after scanning, and a signal feedback component generates the control signal according to the test signal and feeds back the control signal to the photoresist exposure module. 12973twf.ptd Page 24