WO2016034278A1

WO2016034278A1 - Retaining apparatus for retaining a substrate for a treatment process, method for producing the same, and method and apparatus for monitoring a retaining plane of a retaining apparatus

Info

Publication number: WO2016034278A1
Application number: PCT/EP2015/001758
Authority: WO
Inventors: Jochen Taubert; Meik Panitz
Original assignee: Jenoptik Optical Systems Gmbh
Priority date: 2014-09-05
Filing date: 2015-08-29
Publication date: 2016-03-10
Also published as: DE102014012916B3

Abstract

The invention presents a retaining apparatus (100) for retaining a substrate (A) for a treatment process. The retaining apparatus (100) has a main body (110) made of an optically transparent material. The main body (110) here has a substrate-abutment portion (115), in which the substrate (S) can be held in abutment, along a retaining plane (A), against the main body (110). The retaining apparatus (100) also has an optical device (120) which can be, or is, coupled to the main body (110) and is designed in order to illuminate, and form an image of, the retaining plane (A) through the main body (110).

Description

Holding device for holding a substrate for a machining process, procedural ren for producing the same, and method and apparatus for monitoring ei ner holding plane of a holding device

State of the art

The present invention relates to a holding device for holding a substrate for a machining process, to a method of manufacturing a holding device for holding a substrate for a machining process, to a method for monitoring a holding plane of a holding device for holding a substrate for a machining process, on a corresponding device and to a corresponding computer program product. In this case, the present invention relates in particular to the field of production of electronic components, wherein wafers are held by means of so-called chucks.

For example, when sucking or chucking parts of chucks in the field of semiconductor device manufacturing, unwanted particles may be present between the sucked-in part and the chuck surface. DE 10 2008 054 982 A1 discloses a wafer chuck for EUV lithography.

Disclosure of the invention

Against this background, with the present invention, a holding apparatus for holding a substrate for a machining process, a method for manufacturing a holding apparatus for holding a substrate for a machining process, a method for monitoring a retaining plane of a holding apparatus for holding a substrate for a machining process, a corresponding Device and a ent ^¬ speaking computer program product presented according to the main claims. Before ^¬ some embodiments result from the respective dependent claims and the following description.

According to embodiments of the present invention, in particular, an optical inspection of a region can be made possible in which a substrate is mechanically brought into contact or brought against a holding device. Here, for example, egg ^¬ ne alignment of the substrate or a substrate surface with respect to a Holding plane to be determined on the holding device. In particular, according to embodiments of the present invention, a holding device may be provided which is of optically transparent design and has an optical device for inspecting the holding plane. Thus, for example, in this case a holding device, for example a so-called chuck, be provided with interferometer function.

Advantageously, a simple, fast and accurate inspection or measurement method, for example for line monitoring, a cleanliness of the holding device, in particular ^¬ sondere the substrate contact section, and a component flatness of a substrate held can be provided according to embodiments of the present invention in particular. By thus enabled measurement of a flatness of the surface of a substrate or part in the held, for example, sucked, state, a control can be then carried out as to whether the relationship when holding or Chucken, such as suction, a substrate on the holding device between the sucked part and substrate conditioning surface ^¬ wise chuck surface undesirable particles are located. Thus, in particular, a uniformity of a contact of a substrate with a substrate contact portion of the holding device can be determined. Thus, in particular a flatness and Un ^¬ integrity of the sucked substrate or part can be improved.

The invention relates to a holding device for holding a substrate for a machining process, wherein the holding device has the following features: a base body made of an optically transparent material, the base body having a substrate contact section in which the substrate can be held against the base body along a holding plane ; and an optical device which can be coupled or coupled to the base body and which is designed to illuminate and image the retaining plane through the base body.

The holding device may be, for example, a so-called chuck or the like. The substrate may be a wafer, for example a semiconductor wafer, or the like. The machining process may include, for example chemically ^¬ mechanical polishing, etching, mounting of components and / or the like. The main body of the holding device can, on a first main surface, have stratanlageabschnitt. At the substrate abutment portion, the substrate may be durable by a holding force. In this case, the holding device can be designed to transmit the holding force to a voltage applied to the Substratanlageabschnitt substrate. The holding force can be generated for example by negative pressure, electrostatics or the like. The holding plane may extend along a surface of the substrate ^abutment section of the holding device or may correspond to the surface of the substrate system section of the holding device. In this case, the holding plane can correspond to an ideally planar interface between the substrate abutment section and an ideally planar surface of the substrate. At one of the first main surface opposite ^¬ lying, second main surface of the base body, the optical device may be mechanically coupled or is coupled to the base body. In this case, the optical device may be optically or optically and mechanically coupled to the base body. The optical device may have a lighting unit for illuminating or exposing the holding plane and an imaging unit for imaging the illuminated or illuminated holding plane.

According to one embodiment, the optical device may be designed to image the holding plane interferometrically. In this case, the optical device can be ausgebil ^¬ det to image an interference pattern in the holding plane. Such an embodiment has the advantage that it can be detected in a simple and reliable manner on the basis of interference patterns, whether a substrate located on the Substratanlageabschnitt in Appendix substrate rests evenly or free of space against the Substratanlageabschnitt.

In this case, the optical device may have a coherent light source, which is ausgebil ^¬ det to illuminate the holding plane by means of coherent light. Such exporting ^¬ approximate shape offers the advantage that the holding plane can be so BL LEVEL ^¬ tet or exposed by means of coherent light, that a meaningful picture of a keeping quality and a uniformity of a concern of a substrate to the substrate contact portion in the holding plane can be obtained.

In particular, the optically transparent material of the base body may comprise glass or silicon. Such an embodiment provides the advantage that thus the reason ^¬ body of the holder can be produced from an inexpensive, easily processed and / or widespread and popular material. According to an embodiment, the base body in the substrate abutment portion may have a surface layer formed to at least reduce molecular bonding of the substrate to the substrate abutment portion. Such an embodiment offers the advantage that a uniform contact and easy detachment of a 5 nes substrate with respect to the Substratanlageabschnitts can be made possible.

According to one embodiment, the retaining device may comprise a Vakuumansaugvorrich ^¬ tung, which is designed to suck the substrate. Such an embodiment may possibly avoid touching the substrate.

0

There is also presented a method for manufacturing a holding device for holding a sub ^¬ strats for a machining process, the method comprising the steps of:

5 forming a base body with a Substratanlageabschnitt, in which the substrate along a holding plane in abutment against the base body is durable, made of an optically transparent material; and

Coupling an optical device to the base body, wherein the optical device is designed to illuminate and image the retaining plane through the base body.

By carrying out the method of manufacturing, an embodiment of the above-mentioned holding device can be manufactured. This can in particular the

5 base body of an optically transparent material, such as glass, silicon or the like are manufactured and can be installed on a remote from the Substratanlageabschnitt back of the body an optical device or an optical system for lighting and imaging, which is designed to optionally in the holding plane or intake level

10 to detect reference pattern and to allow an evaluation of the same.

Furthermore, a method for monitoring a holding plane of a holding device for holding a substrate for a machining process is presented, the method being feasible in conjunction with an embodiment of the abovementioned holding device of S5, the method having the following steps: Applying a control signal to the optical device to illuminate and image the holding plane;

Reading image data representing the illuminated and imaged holding plane from the optical device; and

Evaluating the image data for an irregularity in the holding plane.

In the step of applying, the control signal can be applied to an interface to the optical device. In the step of reading, the image data of a

Interface to the optical device are read. An irregularity may be a presence of a particle on the substrate abutting portion, a presence of a gap between the abutting substrate and the substrate abutment portion, and additionally or alternatively unevenness in comparison with a uniformity of abutment of the substrate against the substrate abutting portion

Represent holding device. Thus, the method can also be used to monitor a uniformity of a concern of the substrate in the holding plane against the Substratan ^¬ storage section of the holding device.

In one embodiment, in the step of applying, the control signal may be applied to an optical device configured to illuminate and interferometrically image the holding plane by coherent light. In this case, in a state of the substrate held on the holding device in the step of evaluating, in the presence of at least one foreign particle and additionally or alternatively at least

5 of an empty volume between the substrate abutment portion and the substrate in the Hal ^¬ teebene occurring interference pattern in the image data are determined. The Leervo ^¬ lumen may represent a caused by a foreign particle, and additionally or alternatively a Unebenhei ^¬ th of the substrate located in the space between the plant ^¬ sub strate and the substrate contact portion. Such an embodiment

The advantage that foreign particles, intermediate spaces and the like in the region of the Hal ^¬ tebene interferometrically particularly safe, can be detected easily and quickly.

Also, the method may comprise a step of determining a cleanliness of the substrate at ^¬ layer portion and additionally or alternatively a planarity of the substrate in a 55 held on the holding device state of the substrate using the ausgewer ^¬ ended image data. Cleanliness can also be determined if the sub- strat spaced from the holding device is arranged. If no irregularity is found in a step of evaluating, thus, the substrate is uniformly abutted in the holding plane on the substrate abutment portion, a planarity of the substrate can be assumed. Such an embodiment offers the advantage that, even in a running process, during which a substrate is held on the holding device, it is possible to draw conclusions about a perfect or faulty state of the holding device and of the substrate from a quality of the feed.

It is also an apparatus for monitoring a holding plane of a holding device for holding a substrate presented for a machining process, wherein the holding ^¬ device is an embodiment of the above-mentioned holding device, the device comprising the following features: means for applying a control signal to the optical Means for illuminating and imaging the holding plane; means for reading image data representing the illuminated and imaged retainer plane from the optical device; and means for evaluating the image data for an irregularity in the holding plane.

The device is designed to implement or implement the steps of an embodiment of the above-mentioned method for monitoring in corresponding devices. Also by this embodiment of the invention in the form of a device, the object underlying the invention can be solved quickly and efficiently.

In the present case, a device can be understood as meaning an electrical device which outputs control signals and / or data signals and processes sensor signals in dependence thereon. The device may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based embodiment, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the device. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces Software modules that are present for example on a microcontroller in addition to other software modules.

A computer program product with program code which can be stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the embodiments described above if the program product is installed on a computer or a device is also of advantage is performed.

The invention will now be described by way of example with reference to the accompanying drawings. Show it:

Fig. 1 is a schematic representation of a holding device according to an embodiment of the present invention;

FIG. 2 shows a schematic representation of the holding device from FIG. 1 and a monitoring device according to an exemplary embodiment of the present invention;

3 is a flowchart of a method of manufacturing according to an embodiment of the present invention; and

4 is a flowchart of a method of monitoring according to an embodiment of the present invention.

In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similar acting, with a repeated description of these elements is omitted.

1 shows a schematic representation of a holding device 100 according to an embodiment of the present invention. The holding device 100 is designed to hold a substrate S for a processing process of the substrate S. When Hal ^¬ tevorrichtung 100 concerns in this case, for example, a so-called chuck, and the substrate S is a wafer, for example, a semiconductor material. In the illustration of FIG. 1, the substrate S is shown in a state held on the holding device 100.

The holding device 100 has a main body 1 10, which is formed from an optically transparent material. The transparent material may comprise glass or silicon. In this case, the main body 1 10 on a first side or Hauptober ^¬ surface a Substratanlageabschnitt 1 1 5 on. In the Substratanlageabschnitt 1 15, the substrate S along a holding plane A in abutment against the base body 1 10 is stable.

Here, the holding plane A corresponding to a boundary between the Substratanlageab ^¬ section 1 1 5 of the base 1 10 and at least a portion of a the sub ^¬ stratanlageabschnitt 1 1 5 facing the main surface of the substrate S. The substrate S or the substrate bearing portion 1 1 5 facing major surface of the substrate S is held in a first section in abutment against the Substratanlageabschnitt 1 1 5. In a second subsection of the substrate S, a gap or void volume between the substrate abutment portion 1 1 5 and the substrate S and the main surface of the substrate S facing the Substratanlageabschnitt 1 1 5 is arranged. The gap is due to a particle P located in the gap.

The holding device 1 10 further comprises an optical device 120 which is optically coupled to the main body 1 10. Optionally, the optical device 120 may additionally be mechanically coupled to the base body 110, even if this is not shown in FIG. The optical device 120 is arranged on a second side or main surface of the main body 1 10, which is opposite to the first side or main surface of the main body 1 10. In this case, the optical device 120 is designed to illuminate and illuminate and image or record the holding plane A through the optically transparent main body 110.

According to the exemplary embodiment of the present invention illustrated in FIG. 1, the optical device 120 has a coherent light source 121 for illuminating or exposing the holding plane A through the main body 110. Specifically, the coherent light source 1 21 is formed to illuminate the holding plane A by means of coherent light. Between the light source 121 and the main body 110, a first imaging system 122 of the optical device 120 is arranged in a beam path shown symbolically in FIG. 1 and emanating from the light source 121 according to the exemplary embodiment of the present invention shown in FIG. The first imaging system 122 may in this case comprise at least one optical element.

Is between the first imaging system 122 and the base body 1 10 in which emanating from the light source 1 1 beam path, according to the illustrated in Fig. 1 From ^¬ exemplary implementation of the present invention further comprises a partially mirrored optical Ele ^¬ element 123 of the optical device 1 20 arranged. The partially reflecting optical ele ment ^¬ 123 is transparent to light from the light source 121 and at least partially reflective to light returning from the holding plane A. The partially mirrored optical element 123 is configured to redirect at least a portion of the returning light from the illuminated holding plane A according to the embodiment of the present invention shown in FIG. 1 to a second imaging system 124 of the optical device 120.

The second imaging system 124 may in this case comprise at least one optical element. The second imaging system 124 is arranged between the partially mirrored optical element 123 and a camera 125 of the optical device 120 according to the embodiment of the present invention shown in FIG. The camera 125 is designed to detect an interferometric image of the holding plane A. Furthermore, the camera 125 is designed to generate and / or provide image data representing the illuminated and imaged holding plane A or an interference pattern in the holding plane A.

According to the Fig. 1 illustrated exemplary embodiment of the present invention is configured ^¬ with the optical device 120 to illuminate the holding level A by means of coherent light and illuminate and interferometrically map. In this case, an interference pattern in the depicted holding plane A or in the image data is caused by the presence of the particle P or the gap caused thereby.

According to one embodiment, the optical device 120 may include the light source 121, optionally at least one of the imaging systems 122 and / or 124, the teilver ^¬ reflected optical element 123, and optionally the camera 125 have. According to another embodiment, the base body 1 10 in the Substratanlageabschnitt 1 1 5 have a surface layer. The surface layer is formed to reduce or prevent molecular bonding of the substrate S to the substrate abutting portion 11.5.

FIG. 2 shows a schematic representation of the holding device 100 from FIG. 1 and a monitoring device 200 according to an exemplary embodiment of the present invention. The monitoring device 200 is a device for monitoring the holding plane of the holding device 100. In the representation of FIG. 2, only the main body 110 and the optical device 120 are shown by the holding device 100.

The monitoring device 200 has an application device 231, which is designed to apply a control signal 232 to the optical device 120. The control signal 232 is adapted to cause the optical device 120, the holding plane ^¬ be illuminated or exposed to light and reflects or absorbs. Specifically, the applying means 231 may be configured to apply the control signal 232 at least to the light source of the optical device 120.

The monitoring device 200 also has a read-in device 233 for reading image data 234 from the optical device 120. In this case, the image data 234 represent the illuminated and imaged holding plane. The reading device 233 may be configured to read the image data 234 from the camera of the optical device 120. Furthermore, the read-in device 233 is designed to forward the image data 234 to an evaluation device 235 of the monitoring device 200.

The evaluation device 235 is designed to receive the image data 234. Also, the evaluation device 235 is configured to analyze the image data 234 with respect to a Un ^¬ regularity in the holding plane. Optionally, the evaluation device 235 is further formed to which repre ^¬ sentieren to provide evaluation data 236, the evaluated image data.

According to one embodiment, the monitoring device 200 further comprises a determination device 237. The determination device 237 is designed to receive the evaluation data 236 or the evaluated image data from the evaluation device 235. Furthermore, the determination device 237 is designed to operate under Use of the evaluation data 236 or evaluated image data to determine a cleanliness of the Substratanlageabschnitts. Additionally or alternatively, the determination device 237 is designed to determine a planarity of the substrate using the evaluation data 236 or evaluated image data in a state of the substrate held on the holding device 100.

Optionally, the camera of the optical device 120 of the holding device 100 may be part of the monitoring device 200. In one embodiment, the fixture 100 and the monitor 200 may be part of a common system.

3 shows a flow chart of a method 300 for manufacturing a holding device for holding a substrate for a processing process according to an embodiment of the present invention. By carrying out the method 300, the holding device from FIG. 1 or FIG. 2 can be advantageously produced.

In this case 300, the method includes a step 310 of forming a base body on a substrate with contact section, in which the substrate along a support plane in at ^¬ position is stable against the base body, of an optically transparent material.

Also, the method 300 includes a step 320, subsequent to the step 310 of forming, of copying an optical device to the main body. In step 320 of the coupling, in this case the optical device is optically or optically and mechanically coupled to the base body. In this case, the optical device coupled to the base body in step 320 of the head is designed to illuminate and image the retaining plane through the base body.

Fig. 4 shows a flow diagram of a method 400 for monitoring a Halteebe ^¬ ne a holding device for holding a substrate for a machining process ge ^¬ Mäss an embodiment of the present invention. The method 400 for monitoring can be advantageously carried out in conjunction with or using the holding device from FIG. 1 or FIG. 2.

The method 400 includes a step 431 of applying a control signal to the optical device to illuminate and image the holding plane. The method 400 also has a step 433 of insertion following step 431 of the application. sens image data from the optical device. Here, the image data represent the illuminated and imaged holding plane. Furthermore, the method 400 has a step 435 following the step 433 of reading in order to evaluate the image data regarding an irregularity in the holding plane. Thus, by carrying out the method 400, the holding level can be monitored for an irregularity.

Optionally, the method 400 also includes a step 437 of determining cleanliness of the substrate abutment portion and additionally or alternatively planarizing the substrate using the evaluated image data when the substrate is held on the fixture.

According to one embodiment, the control signal is applied to an optical device in step 431, the application, which is adapted to illuminate the support plane by means of coherent light and interferometrically depict how the optical Einrich ^¬ tung the holding device of FIG. 1 or FIG. 2 In this case, in step 435 of the evaluation, an interference pattern occurring in the image data in the presence of at least one foreign particle and / or at least one empty volume between the substrate contact section and the substrate is determined in the image data when the substrate is held on the Haite device.

The embodiments described and shown in the figures are chosen only by way of example. Different embodiments may be combined together or in relation to individual features. An ^exemplary embodiment can also be supplemented by features of a further exemplary embodiment.

Furthermore, method steps according to the invention can be repeated as well as carried out in a sequence other than that described.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, then this is to be read such that the ^exemplary embodiment according to one embodiment either the first feature and the second feature and according to another embodiment either has only the first feature or only the second feature. LIST OF REFERENCE NUMBERS

100 holding device

1 10 basic body

1 1 5 substrate abutment section or holding surface or suction surface

120 optical device

121 light source

122 first imaging system

123 partially mirrored optical element

124 second imaging system

125 camera

A holding level

P particles or foreign particles

S substrate

200 monitoring device

231 mooring device

232 control signal

233 reading device

234 image data

235 evaluation device

236 evaluation data

237 Determination device

300 method of manufacturing

310 step of molding

320 step of Koppeins

400 procedures for monitoring

431 step of mooring

433 step of reading

435 step of the evaluation

437 step of determining

Claims

claims

1 . Holding device (100) for holding a substrate (S) for a machining process, wherein the holding device (100) has the following features: a base body (1 10) of an optically transparent material, wherein the base body (1 10) has a substrate abutment portion (1 1 5), in which the substrate (S) along a holding plane (A) in abutment against the base body (1 10) is durable; and with the basic body (1 10) can be coupled or coupled optical device (120) which is adapted to the support plane (A) through the basic body (1 10) to illuminate toward ^¬ and map.

2. Holding device (100) according to claim 1, wherein the optical device (120) is designed to form the holding plane (A) interferometrically.

3. Holding device (100) according to one of the preceding claims, wherein the optical device (120) comprises a coherent light source (121) which is designed to illuminate the holding plane (A) by means of coherent light.

4. Holding device (100) according to one of the preceding claims, wherein the optically transparent material of the base body (1 10) comprises glass or silicon.

5. Holding device (100) according to one of the preceding claims, wherein the base body (1 10) in the Substratanlageabschnitt (1 1 5) has a surface layer which is adapted to a molecular bonding of the substrate (S) to the Substratanlageabschnitt (1 1 5) at least reduce.

6. The method (300) for producing a holding device (100) for holding a substrate (S) for a Bearbeitungsproz ^ess', the method (300) comprising the steps of:

Molding (310) a base body (1 10) with a Substratanlageabschnitt (1 1 5), in which the substrate (S) along a holding plane (A) in abutment against the base body (1 10) is durable, made of an optically transparent material; and Coupling (320) an optical device (120) to the base body (1 10), wherein the optical device (120) is designed to illuminate and image the retaining plane (A) through the base body (110).

7. Method (400) for monitoring a holding plane (A) of a holding device (100) for holding a substrate (S) for a processing process, the method (400) in conjunction with a holding device (100) according to one of claims 1 to 6 executable, the method (400) comprising the following steps:

Applying (431) a control signal (232) to the optical device (120) to illuminate and image the holding plane (A);

Reading (433) from the optical device (120) image data (234) representing the illuminated and imaged retainer plane (A); and

Evaluating (435) the image data (234) for an irregularity (P) in the holding plane (A).

The method (400) of claim 7, wherein in the step (431) of applying, the control signal (232) is applied to an optical device (120) adapted to illuminate the holding plane (A) by coherent light and interferometrically In a state of the substrate (A) held on the holding device (100) in the evaluation step (435), a presence of at least one foreign particle (P) and / or at least one empty volume between the substrate abutment section (1 1 5) and the Substrate (A) in the holding plane (A) occurring interference pattern in the image data (234) is determined.

The method (400) according to any one of claims 7 to 8, comprising a step (437) of determining a cleanliness of the substrate abutment portion (15) and / or a planarity of the substrate (S) in a state held on the holding device (100) of the substrate (S) using the evaluated image data.

10. Device (200) for monitoring a holding plane (A) of a holding device (100) for holding a substrate (S) for a machining process, wherein the holding ^¬ device (100) is a holding device (100) according to one of claims 1 to 6 wherein the device (200) has the following features: means (231) for applying a control signal (232) to the optical device (120) to illuminate and image the holding plane (A); means (233) for reading image data (234) representing the illuminated and imaged retainer plane (A) from the optical device (120); and means (235) for evaluating the image data (234) for an irregularity (P) in the holding plane (A). Computer program product with program code for carrying out the method

(400) according to any one of claims 7 to 9, when the program product is executed on a device (200).