Overlay measurement device with optical path protection mechanism

Abstract

The utility model provides an overlay measuring device with a light path protection mechanism, which is used for measuring interlayer overlay errors of a sample with overlay marks, and the overlay marks comprise a first overlay mark and a second overlay mark which are respectively formed on different layers. The overlay measurement device provided with an optical path protection mechanism includes: an illumination optical system configured to illuminate an overlay mark on a sample; a detector configured to receive reflected light from the overlay mark and generate an overlay mark image; an imaging optical system including a lens assembly configured to image the reflected light on the detector; a focus actuator configured to adjust a distance between the detector and the lens assembly; and an optical path protection mechanism which is provided between the detector and the lens assembly, surrounds an optical path between the detector and the lens assembly to be isolated from the outside, and is configured to adjust the length according to a change in the distance between the detector and the lens assembly.

Description

Technical Field

[0001] The utility model relates to an overlay measuring device, and more particularly to an overlay measuring device provided with an optical path protection mechanism, which blocks the optical path between a detector moving along an optical axis and a lens assembly to prevent external influences. Background Art

[0002] As technology advances, there is a growing demand for reducing the size of semiconductor devices and increasing the density of integrated circuits. In order to meet such requirements, a variety of important conditions need to be met. Overlay tolerance is one of these important conditions.

[0003] Semiconductor devices are manufactured through many manufacturing processes. In order to form an integrated circuit on a wafer, many manufacturing processes are required to sequentially form the desired circuit structure and elements at specific locations. The manufacturing process generates patterned layers on the wafer in sequence. Through such repeated stacking processes, an electrically activated pattern is generated within the integrated circuit. At this time, if the structures are not aligned within the error range allowed in the production process, interference will occur between the electrically activated patterns, which may cause problems with the performance and reliability of the manufactured circuit. In order to measure and verify the alignment errors between these layers, overlay measurement is used.

[0004] The general overlay measurement method is used to measure and verify whether the alignment between two layers is within the allowable error range. One method is to form a structure called an overlay mark at a specific position on the substrate and use an optical image acquisition device to photograph the structure to measure the overlay. The structure used for measurement is designed to be able to measure the overlay in at least one direction of the X direction and the Y direction for each layer. Each structure is designed to be a symmetrical structure, and the center value between the structures arranged in the symmetrical direction is calculated as the representative value of the layer, and the relative difference between the representative values ​​of each layer is calculated to derive the overlay error.

[0005] In the case of measuring the overlay of two layers, such as Figure 1 and Figure 2 As shown, the overlay error can be measured by forming a quadrilateral main scale 1 (outer box) and a quadrilateral sub-scale 2 (inner box) smaller than the main scale 1 on two consecutive layers, photographing the main scale 1 and the sub-scale 2 at one time, and comparing the center of the main scale 1 with the center of the sub-scale 2.

[0006] However, in such a conventional method, when the height difference between the layer formed with the main scale 1 and the layer formed with the sub-scale 2 is large, if one of the main scale 1 and the sub-scale 2 is focused on, the other one cannot be focused on, so there is a problem that the other one that is not focused appears blurred.

[0007] In order to solve this problem, a method of using two cameras (detectors) to respectively photograph the main scale 1 and the auxiliary scale 2 may also be adopted. Figure 3 As shown in FIG. 1 , after focusing on the main scale 1, a waveform representing the change in intensity at each position is obtained to obtain the center value C1 of the main scale 1, and Figure 4 As shown, after focusing on the sub-scale 2, the wavelength representing the change in intensity at each position is acquired to obtain the center value C2 of the sub-scale 2, and they are compared, thereby measuring the overlay error between the two layers.

[0008] For example, Korean Patent No. 10-2120551 discloses an overlay measurement device including a first detector, a second detector, and a focus actuator configured to adjust the position of the second detector in the optical axis direction. In Korean Patent No. 10-2120551, an overlay mark image focused on a first overlay mark can be obtained using the first detector, and an overlay mark image focused on a second overlay mark can be obtained using the second detector.

[0009] However, there is a problem that the airflow and vibration generated in the process of adjusting the optical axis position of the second detector for focusing, particulate matter penetrating into the space between the second detector and the lens assembly, and external light may cause the quality of the overlay mark image obtained from the second detector to deteriorate.

[0010] Prior art literature

[0011] Patent Literature

[0012] Korean Patent No. 10-2120551 Utility Model Content

[0013] The utility model aims to improve the above-mentioned problem and has the object of providing an overlay measuring device with an optical path protection mechanism arranged between a detector and a lens assembly.

[0014] The above-mentioned purpose of the utility model can be achieved through the following technical solutions.

[0015] The utility model provides an overlay measurement device with an optical path protection mechanism, which measures the inter-layer overlay error of a sample with overlay marks formed thereon, wherein the overlay marks include a first overlay mark and a second overlay mark respectively formed on different layers, and the overlay measurement device with the optical path protection mechanism includes: an illumination optical system, which is configured to illuminate the overlay marks on the sample; a detector, which is configured to receive reflected light from the overlay marks and generate an image of the overlay marks; an imaging optical system, which includes a lens component configured to image the reflected light on the detector; a focusing actuator, which is configured to adjust the distance between the detector and the lens component; and an optical path protection mechanism, which is arranged between the detector and the lens component, surrounds the optical path between the detector and the lens component to isolate it from the outside, and is configured to adjust the length according to the change in the distance between the detector and the lens component.

[0016] Among them, the optical path protection mechanism includes a plurality of hollow tubes with gradually decreasing cross-sectional areas, and the optical path protection mechanism is constructed in a manner that allows the length of the optical path protection mechanism to be adjusted so that one hollow tube can be pulled out from or introduced into another adjacent hollow tube with a larger cross-sectional area.

[0017] The optical path protection mechanism is configured to prevent a hollow tube with a smaller cross-sectional area from falling off from another adjacent tube with a larger cross-sectional area by causing the end of the hollow tube with a smaller cross-sectional area to be clamped at the end of the hollow tube with a larger cross-sectional area.

[0018] Wherein, the optical path protection mechanism is made of aluminum or aluminum alloy, and the inner peripheral surface of the optical path protection mechanism is black.

[0019] Wherein, the lens assembly includes a zoom lens.

[0020] Wherein, the hollow tube is a round tube or a polygonal tube.

[0021] The effects of the utility model are as follows.

[0022] The advantage of the overlay measurement device of the utility model is that it reduces or blocks the airflow and vibration caused by the movement of the detector along the optical axis, and the particles and external light that penetrate into the space between the detector and the lens assembly, thereby improving the quality of the overlay mark image. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a plan view of the overlay mark.

[0024] Figure 2 yes Figure 1 Side view of the overlay mark shown.

[0025] Figure 3 Shown in focus Figure 1 The waveform of the intensity change at each position of the signal obtained in the state of the main scale with overlay marks is shown.

[0026] Figure 4 Shown in focus Figure 1 The waveform of the change in intensity at each position of the signal obtained in the state of the sub-scale with an overlay mark is shown.

[0027] Figure 5 It is a conceptual diagram of an overlay measurement device according to an embodiment of the present invention.

[0028] Figure 6 is a graph exemplarily showing the intensity corresponding to the wavelength of illumination from an illumination source.

[0029] Figure 7 It is a diagram for explaining a method of irradiating light to the first set of engraved marks and the second set of engraved marks formed on the sample.

[0030] Figure 8 It is shown by Figure 5 A diagram of a first set of engraved marking images acquired by a first detector is shown.

[0031] Fig. 9 It is shown by Figure 5 A second set of engraved mark images acquired by a second detector is shown.

[0032] Fig.10 is a diagram showing an image obtained by combining the first set of engraved mark images and the second set of engraved mark images.

[0033] Figures 11(a) and 11(b) show Figure 5 A perspective view of a portion of the utility model is shown.

[0034] Fig.12 11(a) and 11(b) are cross-sectional views of the optical path protection mechanism.

[0035] Reference numerals

[0036] S: sample, OM1: first set of engraved marks, OM2: second set of engraved marks, I1: first set of engraved mark image, I2: second set of engraved mark image, 100: overlay measurement device, 10: height difference measurement optical system, 20: illumination optical system, 30: main beam splitter, 40: first detector, 50: second detector, 60: first imaging optical system, 70: second imaging optical system, 80: optical path protection mechanism. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the embodiments of the present invention can be deformed into a variety of other forms, and the scope of the present invention should not be interpreted as being limited to the embodiments described in detail below. The embodiments of the present invention are provided to more completely illustrate the present invention to those of ordinary skill in the art. Therefore, the shapes of the elements in the figures are exaggerated to emphasize a clearer description, and the elements represented by the same reference numerals in the figures refer to the same elements.

[0038] Figure 5 1 is a conceptual diagram of an overlay measurement device according to an embodiment of the present invention. The overlay measurement device 100 is a device for measuring an error between a first overlay mark OM1 and a second overlay mark OM2 respectively formed on different layers of a wafer w.

[0039] For example, Figure 7 As shown, the first overlay mark OM1 may be an overlay mark formed on a previous layer, and the second overlay mark OM2 may be an overlay mark formed on a current layer. The overlay mark is formed on the scribe line simultaneously with the formation of a layer for forming a semiconductor device in a die region. For example, the first overlay mark OM1 may be formed together with an insulating film pattern, and the second overlay mark OM2 may be formed together with a photoresist pattern formed on the insulating film pattern.

[0040] In this case, the second overlay mark OM2 is exposed to the outside, but the first overlay mark OM1 is in a state of being blocked by the photoresist layer and is composed of an oxide having optical properties different from the second overlay mark OM2 made of the photoresist material. In addition, the heights of the first overlay mark OM1 and the second overlay mark OM2 are different from each other.

[0041] In the present invention, the first overlay mark OM1 and the second overlay mark OM2 are focused on respectively to acquire images, and the magnification is adjusted in consideration of the height difference between the first overlay mark OM1 and the second overlay mark OM2, so that the overlay error can be measured more accurately.

[0042] As an overlay mark, a box in box (BIB, see Figure 1 ), AIM (advanced imaging metrology) overlay marks, etc. The following will mainly be described based on the simple box-in-box overlay mark.

[0043] like Figure 5As shown, an overlay measurement device of an embodiment of the utility model includes a height difference detection optical system 10, an illumination optical system 20, a main beam splitter 30, a first detector 40, a second detector 50, a first imaging optical system 60, a second imaging optical system 70, and an optical path protection mechanism 80.

[0044] The height difference detection optical system 10 plays a role in measuring the height difference Δh between the first set of engraved marks OM1 and the second set of engraved marks OM2. The height difference detection optical system 10 can be constructed using various optical elements. As the height difference detection optical system 10, various optical systems for autofocus can be used.

[0045] For example, Figure 5 As shown, the height difference detection optical system 10 may include a light source 11, a plane convex lens 13 for refracting a light beam from the light source 11, a beam splitter 15, and an image sensor 19. In addition, a hot mirror 17, a beam splitter 31, and an objective lens 32 used together with the first imaging optical system 60, the illumination optical system 20, and the second imaging optical system 70 may also be included.

[0046] A laser diode or a light emitting diode can be used as the light source 11. The light source 11 can generate light in an infrared wavelength band, for example.

[0047] The light generated by the light source 11 passes through the plane convex lens 13 and the beam splitter 15. When a laser is used as the light source 11, a polarization beam splitter can be used as the beam splitter 15. This is because the reduction in the amount of light during reflection and transmission can be minimized.

[0048] The hot mirror 17 reflects light in the infrared wavelength band. The light reflected from the hot mirror 17 passes through the beam splitter 31 and enters the objective lens 32 .

[0049] The objective lens 32 plays the role of focusing light to the measurement position on the surface of the sample S and collecting the reflected light reflected at the measurement position on the surface of the sample S. The reflected light collected by the objective lens 32 is reflected by the hot mirror 17 after passing through the beam splitter 31. The reflected light reflected from the hot mirror 17 is reflected from the beam splitter 15 to the image sensor 19 side, and then focused to the image sensor 19 by the focusing lens 18. Since the light belonging to the infrared wavelength band cannot pass through the hot mirror 17, the light used to measure the height difference will not be incident on the first detector 40.

[0050] The image sensor 19 receives the reflected light from the sample S. The image sensor 19 may be a CCD sensor or a CMOS sensor. By analyzing the contrast of the image from the image sensor 19, it is possible to determine whether the image is in focus. Therefore, by analyzing the optical signal from the image sensor 19 corresponding to the distance between the objective lens 32 and the sample S, the position of the objective lens 32 when it is focused on the first set of engraved marks OM1 and the position of the objective lens 32 when it is focused on the second set of engraved marks OM2 can be found. Then, by comparing these positions, the height difference Δh between the first set of engraved marks OM1 and the second set of engraved marks OM2 can be known.

[0051] The illumination optical system 20 serves to illuminate the overlay mark. The illumination optical system 20 can be formed by using a variety of optical elements. For example, Figure 5 As shown, the illumination optical system 20 may include an illumination source 25 and a relay lens 28. In addition, a beam splitter 31 and an objective lens 32 may also be used as a part of the illumination optical system 20.

[0052] The illumination source 25 may generate illumination in the form of both first illumination including a spectral band suitable for acquiring a clear image from the first set of inscribed markings OM1 and second illumination including a spectral band suitable for acquiring a clear image from the second set of inscribed markings OM2.

[0053] Figure 6 is a graph exemplarily showing the intensity corresponding to the wavelength of illumination from an illumination source. For example, Figure 6 The first illumination may be light in the visible light region, and the second illumination may be light in the near-infrared (NIR) region.

[0054] The illumination source 25 may include a broadband light source and a plurality of variable color filters. The broadband light source generates light of a relatively wide wavelength band. As the broadband light source, an arc lamp, a discharge lamp, an electrodeless lamp, a halogen lamp, a xenon lamp, etc. may be used. The variable filter plays a role in adjusting the central wavelength and bandwidth of the light generated by the light source.

[0055] Illumination from the illumination source 25 passes through the relay lens 28 and is reflected by the beam splitter 31 toward the objective lens 32 .

[0056] The objective lens 32 focuses the illumination reflected from the beam splitter 31 to the measurement position of the sample S and collects the light beam reflected from the measurement position. The objective lens 32 is provided on a lens focus actuator 33 for adjusting the distance between the objective lens 32 and the sample S.

[0057] The main beam splitter 30 serves to separate the light beam collected by the objective lens 32 into two light beams. The main beam splitter 30 can be a beam splitter 30 that splits the incident light into two spectrally distinct output light beams. For example, the main beam splitter 30 can include a tube beam splitter and a dichroic filter. The dichroic filter is a filter that transmits light beams of a specific wavelength. The light beam collected by the objective lens 32 is separated into two light beams in the main beam splitter 30 after passing through the beam splitter 31 and the hot mirror 17. That is, it is separated into a first light beam for detecting the first set of engraved marks OM1, and a second light beam for detecting the second set of engraved marks OM2. The wavelength band of the first light beam can be substantially the same as the first illumination, and the wavelength band of the second light beam can be substantially the same as the second illumination.

[0058] like Figure 6 As shown, the first illumination suitable for detecting the first set of engraved marks OM1 and the second illumination suitable for detecting the second set of engraved marks OM2 have different central wavelengths and narrow bandwidths, and thus can be easily separated into two light beams using a dichroic filter.

[0059] The first detector 40 plays a role of receiving the first light beam which is one of the light beams split by the main beam splitter 30 and generating a first overlay mark image I1.

[0060] Figure 8 It is shown by Figure 5 FIG. 1 is a diagram of a first set of engraved marking images I1 acquired by a first detector. Figure 8 As shown, the first overlay mark OM1 of the first overlay mark image I1 acquired by the first detector 40 is displayed clearly, while the second overlay mark OM2 is displayed blurred. This is because the focus is on the first overlay mark OM1.

[0061] The second detector 50 plays a role of receiving the second light beam which is the other of the light beams split by the main beam splitter 30 and generating a second overlay mark image I2.

[0062] Fig. 9 It is shown by Figure 5 FIG. 1 is a diagram of a second set of engraved mark images I2 acquired by a second detector. Fig. 9 As shown, the second set of engraved marks OM2 of the second set of engraved marks image I2 acquired by the second detector 50 is displayed clearly, while the first set of engraved marks OM1 is displayed blurred. This is because the second imaging optical system 70 adjusts the optical path of the second light beam to focus on the second set of engraved marks OM2.

[0063] When the general Figure 8 Images and Fig. 9 When the images are aligned and combined, as Fig.10As shown, an overlay mark image in which both the first overlay mark OM1 and the second overlay mark OM2 are clearly shown can be acquired.

[0064] The first imaging optical system 60 serves to image the first light beam onto the first detector 40 .

[0065] like Figure 5 As shown, the first imaging optical system 60 may include a tube lens 65. In addition, the first imaging optical system 60 also uses the objective lens 32, the beam splitter 31, the hot mirror 17, and the main beam splitter 30 of other optical systems.

[0066] The objective lens 32 collects the light reflected from the sample S. The light collected by the objective lens 32 is split into a first light beam and a second light beam by the main beam splitter 30. The first light beam that has passed through the main beam splitter 30 is focused by the tube lens 65 to the first detector 40. At this time, the focus is set with the first overlay mark OM1 as the reference. Therefore, in the first overlay mark image I1 generated by the first detector 40, the first overlay mark OM1 is displayed clearly, and the second overlay mark OM2 is displayed relatively blurred.

[0067] The second imaging optical system 70 plays a role of adjusting the length of the optical path of the second light beam based on the height difference Δh between the first overlay mark OM1 and the second overlay mark OM2 to image the second light beam onto the second detector 50 .

[0068] The second detector 50 detects the light beam reflected by the main beam splitter 30. The second detector 50 is provided on a focus actuator 51. Therefore, the distance between the main beam splitter 30 and the second detector 50 can be adjusted.

[0069] Since the distance between the objective lens 32 and the sample S is adjusted so that the focus is located at the first set mark OM1 based on the first imaging optical system 60, in order to obtain a clear image of the second set mark OM2, it is necessary to use the focusing actuator 51 to adjust the distance between the second detector 50 and the main beam splitter 30 according to the height difference between the first set mark OM1 and the second set mark OM2. The focusing actuator 51 can work based on the signal from the height difference detection optical system 10.

[0070] In this embodiment, the second imaging optical system 70 includes a lens assembly 71 (zoom lens). In addition, the objective lens 32, the beam splitter 31, the hot mirror 17, and the main beam splitter 30 also serve as a part of the second imaging optical system 70.

[0071] The lens assembly 71 is disposed between the main beam splitter 30 and the second detector 50. The lens assembly 71 receives the position change value of the second detector 50 from the height difference detection optical system 10 or the focus actuator 51, and makes the magnification of the second overlay mark OM2 image consistent with that of the first overlay mark OM1 image according to the value. The lens assembly 71 may include a zoom lens.

[0072] Since the optical path distance between the second detector 50 and the main beam splitter 30 is adjusted to be different from the optical path distance between the first detector 40 and the main beam splitter 30 according to the height difference between the first overlay mark OM1 and the second overlay mark OM2, the magnifications of the image acquired by the first detector 40 and the image acquired by the second detector 50 may be different from each other. In order to accurately measure the overlay error, the magnifications should be made consistent.

[0073] The optical path protection mechanism 80 is disposed between the second detector 50 and the lens assembly 71. The optical path protection mechanism 80 serves to surround the optical path between the second detector 50 and the lens assembly 71 to isolate it from the outside. Thus, the airflow and vibration caused by the movement of the second detector 50 along the optical axis direction can be blocked or reduced. In addition, particulate matter and external light that penetrate into the space between the second detector 50 and the lens assembly 71 can be reduced or blocked.

[0074] The optical path protection mechanism 80 can be made of aluminum or aluminum alloy. The inner peripheral surface of the optical path protection mechanism 80 can be black. This is to minimize the reflection of light. The black inner peripheral surface can be obtained by forming a black oxide film by a method such as anodizing.

[0075] The optical path protection mechanism 80 is configured to adjust the length according to the change in the distance between the second detector 50 and the lens assembly 71. As described above, in order to focus on the second overlay mark OM2, it may be necessary to move the second detector 50 in the optical axis direction. In addition, in order to make the magnification of the first overlay mark image I1 and the second overlay mark image I2 consistent, the lens assembly 71 may be moved along the optical axis direction. In such a process, the distance between the second detector 50 and the lens assembly 71 may change.

[0076] Figures 11(a) and 11(b) show Figure 5 A perspective view of a portion of the utility model shown, Fig.12 11(a) and 11(b) are cross-sectional views of the optical path protection mechanism.

[0077] As shown in Figure 11(a), Figure 11(b) and Fig.12As shown, the optical path protection mechanism 80 may include a plurality of hollow tubes 81, 82, 83, 84, 85, 86 with gradually decreasing cross-sectional areas. Although FIG. 11(a) and FIG. 11(b) illustrate that the optical path protection mechanism 80 has six hollow tubes 81, 82, 83, 84, 85, 86, the number of hollow tubes 81, 82, 83, 84, 85, 86 may be selected as needed. Among the plurality of hollow tubes 81, 82, 83, 84, 85, 86, one of the two 81, 86 located at the ends of both sides is fixed to the second detector 50 side, and the other is fixed to the lens assembly 71 side. The hollow tubes 81, 82, 83, 84, 85, 86 may be circular tubes or polygonal tubes such as quadrilateral tubes and hexagonal tubes.

[0078] The hollow tubes 81, 82, 83, 84, 85 can be pulled out from or introduced into another adjacent hollow tube 82, 83, 84, 85, 86 with a larger cross-sectional area according to the change in the distance between the second detector 50 and the lens assembly 71.

[0079] Fig. 11(a) shows a state where all hollow tubes 81, 82, 83, 84, 85 are introduced to shorten the length of the optical path protection mechanism 80. Fig. 11(b) shows a state where all hollow tubes 81, 82, 83, 84, 85 are withdrawn to lengthen the length of the optical path protection mechanism 80.

[0080] The hollow tubes 81, 82, 83, 84, 85, and 86 are configured so that the ends of the hollow tubes with smaller cross-sectional areas are clamped to the ends of the hollow tubes with larger cross-sectional areas in order to prevent the hollow tubes with smaller cross-sectional areas from falling off from the adjacent hollow tubes with larger cross-sectional areas. Fig.12 As shown, the upper end of the hollow tube with a larger cross-sectional area is contracted, and a locking boss may be formed on the outer peripheral surface of the lower end of the hollow tube with a smaller cross-sectional area inserted into the hollow tube.

[0081] The embodiments described above are merely illustrative of preferred embodiments of the present invention. The scope of rights of the present invention is not limited to the described embodiments. Those skilled in the art will be able to make various changes, deformations, and substitutions to the embodiments within the scope of the technical concept and claims of the present invention, and such embodiments should be understood to fall within the scope of the present invention.

Claims

1. An overlay measurement device with an optical path protection mechanism, which measures the inter-layer overlay error of a sample formed with overlay marks, wherein the overlay marks include a first overlay mark and a second overlay mark respectively formed on different layers, wherein the overlay measurement device with an optical path protection mechanism is characterized in that it comprises: an illumination optical system configured to illuminate the overlay mark on the sample; a detector configured to receive reflected light from the overlay mark and generate an overlay mark image; an imaging optical system including a lens assembly configured to image the reflected light onto the detector; a focus actuator configured to adjust a distance between the detector and the lens assembly; as well as The optical path protection mechanism is arranged between the detector and the lens assembly, surrounds the optical path between the detector and the lens assembly to isolate it from the outside, and is configured to adjust its length according to the change of the distance between the detector and the lens assembly.

2. The overlay measurement device with an optical path protection mechanism according to claim 1, characterized in that: The optical path protection mechanism includes a plurality of hollow tubes with gradually decreasing cross-sectional areas. The optical path protection mechanism is configured to allow one hollow tube to be drawn out from or introduced into another adjacent hollow tube with a larger cross-sectional area in such a manner that the length of the optical path protection mechanism can be adjusted.

3. The overlay measurement device with an optical path protection mechanism according to claim 2, characterized in that: The optical path protection mechanism is configured to prevent a hollow tube with a smaller cross-sectional area from falling off from another adjacent tube with a larger cross-sectional area by causing the end of the hollow tube with a smaller cross-sectional area to be clamped to the end of the hollow tube with a larger cross-sectional area.

4. The overlay measurement device with an optical path protection mechanism according to claim 2, characterized in that: The optical path protection mechanism is made of aluminum or aluminum alloy, and the inner peripheral surface of the optical path protection mechanism is black.

5. The overlay measurement device with an optical path protection mechanism according to claim 1, characterized in that: The lens assembly includes a zoom lens.

6. The overlay measurement device with an optical path protection mechanism according to claim 2, characterized in that: The hollow cylinder is a cylinder or a polygonal cylinder.

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