WO2018011499A1

WO2018011499A1 - Photolithography device and method

Info

Publication number: WO2018011499A1
Application number: PCT/FR2017/051879
Authority: WO
Inventors: Olivier LECARME; Jean-Marc Pascal
Original assignee: Smart Force Technologies
Priority date: 2016-07-11
Filing date: 2017-07-10
Publication date: 2018-01-18
Also published as: FR3053807A1; FR3053807B1

Abstract

The invention relates to a simple and inexpensive photolithography device and method allowing an illumination pattern to be projected onto the surface of a substrate. The device includes a projector, intended to form a projection image, the image defining a pattern, along with a focusing optical system, capable of focusing the image on the surface of a substrate. It also includes an optical image transmission system, capable of forming a control image, representing the pattern projected onto the substrate, the control image being capable of being detected by a control camera, for viewing the projected pattern.

Description

Photolithography device and method

Description

TECHNICAL AREA

The technical field of the invention is the photolithography of substrates for the manufacture of components, for example microfluidic components.

PRIOR ART

The use of photolithography processes is very common in the field of component manufacturing microtechnologies in the field of microelectronics, micromechanics or microfluidics. Photolithography consists of depositing a photolithography resin on a substrate, then exposing the resin to spatially structured light radiation in a two-dimensional pattern so as to degrade only portions of the resin. Under the effect of exposure, the resin degrades. Thus, the surface of the exposed substrate is no longer covered by the resin and can be etched, including wet etchings.

Current photolithography equipment offers remarkable performance, especially from the point of view of spatial resolution. However, they are expensive, bulky and not very flexible. The pattern is formed on the substrate to be treated by interposing opaque masks, having openings corresponding to the pattern that is to be formed on the substrate. The making of such masks is expensive and can take time.

An alternative to the use of standard lithography equipment has been described in the Cordeiro J publications, "Table-top deterministic and colloidal collective assembly using videoprojector lithography", Applied Surface Science 349 (2015) 452-458, as well as in Maisonneuve BGC, "apid mask prototyping for microfluidics", Biomicrofluidics 10, 024103 (2016). These publications describe a device comprising a projector, capable of forming an image, the image being projected onto a substrate so as to form a two-dimensional pattern on the surface of the latter. For this, the objective of the projector is replaced by an optical system for projecting the image on a small surface, typically of the order or less than 10 cm ² . Without seeking to achieve the performance of standard photolithography equipment, such a device is particularly clever, because it allows a photolithography using an inexpensive and easily scalable system. Indeed, the Opaque mask making is not necessary, the projector being able to project an image whose projection on the substrate defines the illumination pattern, also referred to as the insolation pattern, of the resin. This device is particularly suitable for applications that do not require too high resolution. It is also a modular tool, the pattern can be modified at will in real time, which allows to test different patterns without requiring the manufacture of different masks. However, the inventors have found that this device has certain disadvantages. The object of the invention is to improve the performance of a photolithography device based on the use of an image projector, in particular by improving the reliability and the spatial resolution of the pattern formed on the substrate.

SUMMARY OF THE INVENTION

An object of the invention is a photolithography device comprising:

an image projector, adapted to receive a digital setpoint and to form a two-dimensional image, representative of the digital setpoint, the two-dimensional image defining an illumination pattern;

a focusing optic, capable of projecting the image formed by the projector, onto the surface of a substrate, arranged in a focal plane of the focusing optics, so as to project the illumination pattern onto said surface in accordance with a projection axis;

the device being characterized in that it comprises:

a deflection optics arranged between the headlamp and the focal plane of the focusing optics, ie between the headlamp and the sample, capable of returning a so-called control image, representative of the projected pattern, along a return axis, intersecting the projection axis;

a camera, arranged along the axis of reference, and able to acquire the control image. The control image thus acquired makes it possible to control the illumination pattern projected on the surface of the substrate. It is also representative of the image formed by the image projector and projected onto the substrate.

The device may include one of the following features, taken separately or in technically feasible combinations:

- The return lens comprises a semi-reflective blade inclined relative to the axis of projection; the focusing optics comprises a tube lens coupled to a lens, in particular an infinitely corrected lens, the return lens being disposed between the tube lens and the lens;

the focusing optics comprises an objective secured to a retaining ring, the device comprising a support on which the retaining ring is able to be fixed in a reversible manner; the support or the retaining ring may comprise at least one magnet so as to ensure a reversible attachment of the ring to said support. The retaining ring comprises a bearing face, capable of being fixed to the support, as well as, preferably, a guide end, in particular a bead, extending from said bearing face, along the axis of projection, said guide end being adapted to be inserted into the support. The support and the retaining ring may be tubular. According to this embodiment, the device may comprise an enclosure, extending from the image projector along the projection axis, to the support receiving the retaining ring, the enclosure enclosing the deflection optics, the device also comprising a rigid holding member extending outside the enclosure, between the projector and the support or between the projector and the retaining ring. This avoids a vibration of the lens held by the retaining ring. The spatial resolution of the illumination pattern projected on the substrate is then improved.

The projector may be a video projector capable of forming a projection image at a frequency of at least one image per second.

The focusing optics is such that the area of the projected image on the substrate can be less than 100 cm ² or less than 10 cm ² or 2 cm ² . Typically, this area is between 5 cm ² and 1 mm ² .

The focusing optics is such that the dimension of the image projected onto the substrate is less than or equal to the size of the image formed by the projector.

Another object of the invention is a method of photolithography of a substrate comprising the following steps:

a) applying a photoresist to a surface of the substrate;

b) disposing said substrate surface in the focal plane of the focusing optics of a photolithography device according to any one of the preceding claims;

c) transmitting a digital instruction into the image projector of said photolithography device; d) activating the projector, so as to project, on the substrate, a projection image representative of the setpoint, the projection image defining an illumination pattern; e) acquisition of a control image by the control camera of the photolithography device;

f) checking the conformity of the projected image on the substrate with the help of the control image.

The method may comprise, depending on the control image:

a relative displacement of the substrate relative to the photolithography device; and / or an adjustment of the focusing optics of the photolithography device. Another object of the invention is an optical system, in particular an objective or a lens, held in a retaining ring, in particular a tubular ring, the retaining ring being able to be fixed, reversibly, to a support, the ring of maintaining or the support comprising at least one magnet, so as to allow reversible attachment of the retaining ring on the support. Preferably:

the support is of tubular geometry, and has an opening opening at a contact surface of the support, against which the ring can be supported;

the retaining ring comprises a bearing face, adapted to be applied against the contact face of the support, as well as an end, said guide end, adapted to be inserted into the opening defined by the support, the end guide extending from a bearing surface, in particular perpendicular thereto;

a magnet or magnets are disposed on the contact face of the support, so as to be in contact with the bearing face of the ring when the guide end of the ring is inserted into the opening of the support;

in a complementary or alternative manner, a magnet or magnets are placed on the bearing face of the ring, so as to be in contact with the contact face of the support when the guide end of the ring is inserted into the ring. opening of the support. Preferably, the contact face of the support and the bearing face of the ring each comprise a magnet, so as to constitute a pair of magnets, each magnet of the pair being of opposite polarity, so as to attract the other magnet of the pair. The contact face of the support and the bearing face of the ring may comprise several pairs of magnets. The ring may be metallic, the metal being ferromagnetic, in which case the magnet or the magnets may be arranged on the contact face of the support. The contact face of the support may be metallic and ferromagnetic, in which case the magnet or the magnets may be placed on the bearing face of the ring. When the bearing face of the ring and the contact face of the support comprise a pair of magnets, or several pairs of magnets, no stress is required as to the material composing the ring and the carrier. The contact face of the support, as well as the bearing face of the ring, can in particular be annular.

According to one embodiment, the retaining ring comprises a guide end in which the contact surface of the suport is able to be inserted until it comes into contact with the bearing face of the ring.

The guide end may extend at an extension distance greater than 1 mm, and preferably greater than 3 mm, from the support surface of the retaining ring. Preferably, the extension distance is less than 10 mm. It is for example equal to 5 mm.

Other advantages and features will emerge more clearly from the description which will suffice from particular embodiments of the invention, given by way of non-limiting examples, and represented in the figures listed below.

FIGURES

FIGS. 1A and 1B respectively represent a front view and a side view of an exemplary device according to the invention.

Figures 2A and 2B illustrate the device, Figure 2B showing a detail of a so-called return channel of the device.

Figures 3A and 3B respectively show a retaining ring, adapted to hold a lens, and a fixing of the retaining ring on a support. Figure 3C shows another configuration of a retaining ring. Figu re 3D represents yet another configuration of the retaining ring.

Fig. 4A shows an example of a target image transmitted to the projector. FIG. 4B shows an illumination pattern formed on a substrate from an image formed by the projector according to the target image shown in FIG. 4A. DESCRIPTION OF PARTICULAR EMBODIMENTS

FIG. 1A shows an example of a photolithography device 1 according to the invention intended to illuminate a substrate 2. The device comprises an image projector 10, in this case a video projector, capable of projecting a two-dimensional image along a projection axis Z. This two-dimensional image defines an illumination pattern M. The projected image comprises a partition according to light parts and dark parts, especially black. The illumination pattern M corresponds to the projection of the clear parts on the substrate. The image projector 10 is for example a video projector, allowing the projection of an image from a digital instruction l _n .

By digital setpoint is meant information transmitted to the projector 10, in a digital format, representing the image to be projected. The digital instruction can be transmitted to the projector via a memory 11, for example a USB key, or by a link with a remote memory, by means of a wired link or wireless link.

Such video projectors are commercially available, and allow images to be formed at a frequency of several images per second, and to project them onto a screen. The inventors have used such a projector for its ability to form a custom image, which can be modified simply by modifying the digital setpoint. The projector comprises an imaging unit 12 I _f , comprising a light source and allowing the formation of the image to be projected from the digital setpoint. The image forming unit may comprise, for example, one or more liquid crystal screens, each screen allowing the formation of an image in a predetermined spectral band. The unit 12 may for example comprise 3 screens, respectively illuminated in red, green or blue spectral bands. The light beams from each liquid crystal display are combined to form an image I _f representative of the setpoint. In the example shown, the projector is marketed by EPSON under the reference EH-TW5300. It comprises three liquid crystal displays, comprising 1920 x 1080 pixels, and making it possible to define a two-dimensional illumination pattern M inscribed in a rectangle of dimensions 13 mm × 7 mm, each pixel corresponding to a square of side 7 μιη. These dimensions define the area of the image I _f formed by the imaging unit.

The projector 10 is generally marketed with a projection lens, making it possible to magnify the image formed, so as to project it on a remote screen with a magnification greater than 1. This objective has been replaced by an optical system 25, allowing the focusing of the image formed by the projector on the 2s surface of a substrate 2, the projected image _p on the substrate being of larger dimensions (e.g., two times greater) similar or reduced compared with the image I _f formed by the imaging unit 12. The image I _f formed by the image forming unit 12 defines an illumination pattern M representative of a geometry of an etching that it is desired to perform on a substrate. Preferably, the image I _f is partitioned between dark portions, for example black, acting as masks and light parts, the latter corresponding to the insolated areas of the surface of the substrate. An example of an illumination pattern is given in connection with FIG. 4A.

In the example shown, the optical system 25 consists of a tube lens 25a coupled to a microscope objective 25b. In this example, the tube lens 25a is a reference Thorlabs lens LBF254-100-A. It has a diameter of 25 mm and a focal length of 100 mm. It is disposed at 100 mm from the image forming unit 12, and is optically coupled to an infinitely corrected objective 25b of the microscope objective type. In this example, the objective 25b has a working distance of 34 mm. This is a branded Mitutoyo lens, QV range, 100mm focal length. The magnification of the focusing optical system 25 corresponds to the ratio of the respective focal lengths of the tube lens 25a and the objective 25b. In this example, the magnification is 1. The size of the projected image 1 _p on the surface 2s of the substrate 2 then corresponds to the size of the liquid crystal screens of the projector, that is to say to the size of the image I _f formed by the projector. It is preferable to use a lens 25b whose working distance is greater than 15 mm or even 20 mm. This allows for a simpler change of purpose.

A substrate 2 is placed in such a way that a surface 2s of the substrate corresponds to the focal plane of the optical system 25. The image _p projected on the substrate 2 by means of the optical system 25 preferably extends according to a area less than 100 cm ² , preferably less than 10 cm ² , or even 2 cm ² . The number of pixels of the image formed by the projector being limited, the more the projected image l _p extends in a weak area, the better is the spatial resolution of the projected illumination pattern, which translates into more photolithography. precise. Typically, an image projected on the surface 2s of the substrate has a width and a length of less than 2 cm or 3 cm. The area of the projected image can be adjusted by changing the magnification of the focusing optical system 25. In general, the image _p projected on the substrate 2 extends over an area of less than twice the the area of the image I _f formed by the imaging unit 12, or even less than the area of the image I _f formed by the imaging unit.

A diaphragm 22, said projection diaphragm, defining an opening of diameter equal to 6 mm, is disposed upstream of the objective 25b, so as to reduce optical aberrations. The inventors have observed that by minimizing the distance between the diaphragm 22 and the objective 25b, the quality of the projected image l _p is improved. Thus, the distance between the diaphragm and the lens is preferably less than 10 mm, and even more preferably less than 5 mm, or even 3 mm or 2 mm. It is preferable that this distance is as small as possible. The use of such a diaphragm reduces the intensity of the projected image, but this allows an increase in depth of field, as well as a significant reduction in vignetting affecting the edges of the projected image. The quality of the projected image is thus improved in terms of uniformity and contrast. Increasing the depth of field makes it easier to focus. The aperture defined by the diaphragm depends on the magnification of the lens. It is 6 mm maximum when the magnification of the objective is between 0.5 and 10. When using a high magnification objective, for example x10, the opening of the diaphragm has a maximum diameter of 4 mm. When a 25x magnification lens is used, the aperture of the diaphragm has a maximum diameter of 2mm.

The surface 2s of the substrate 2 is covered with a photosensitive resin, capable of being degraded by exposure to light radiation, in particular in the light portions defined by the projected illumination pattern. The device may comprise an optical bandpass filter 23, arranged for example upstream of the objective 25b, or upstream of the tube lens 25a, so that the spectral band of the light radiation reaching the substrate 2 is adapted to the sensitivity of the photosensitive resin. For example, when the resin used is a G-lines resin, it is possible to use an optical filter 23 whose bandwidth is centered on 450 nm and whose width at half height is 40 nm. The term "upstream" is to be interpreted by considering the direction of propagation of light between the projector 10 and the substrate 2, according to the arrow shown in broken lines in Figure 1A.

Between the tube lens 25a and the objective 25b, the device comprises a semi-reflecting plate 24, inclined with respect to the projection axis Z, and thus inclined with respect to the surface 2s of the substrate 2. This semi-reflective blade 24 reflective transmitting light from the projector 10 and propagating towards the substrate 2, along the Z axis. It serves as optical return and reflects part of the light emanating from the substrate 2, by reflection or backscattering in the latter, and propagating in a direction opposite to the axis of projection Z, towards a propagation axis X, referred to as the return axis, which in this example is perpendicular to the axis Z. In general, the return axis is secant from the projection axis, and is preferably perpendicular to the latter. The light reflected (and / or backscattered) by the substrate is illustrated by a dotted arrow in Figure 1A. The semi-reflecting blade 24 can be held in a cube, said splitter cube, interposed between the tube lens 25a and the objective 25b. In this example, the reflective plate is provided by Thorlabs under the reference CM1 PB108.

The optical elements located between the imaging unit 12 and the substrate 2, allowing projection of the image formed by the imaging unit, define a projection path 20. In this example, the path projection plate 20 comprises the tube lens 25a, the projection diaphragm 22, the bandpass filter 23, and the objective 25b.

The semi-reflecting plate 24 allows the formation of a control image _1c , representing the image _1p projected onto the substrate, and consequently the illumination pattern M projected onto the surface of the substrate 2. This control image propagates along a return path 30, along the return axis X, to a camera 34, said control camera, which acquires the control image. This makes it possible to visualize the control image _1c and to verify that the illumination pattern M is correctly formed on the surface of the substrate 2. Depending on the control image, the operator can carry out a control adjustment. optical focusing system 25, or a relative displacement of the substrate 2 relative to the device 1. For this purpose, the substrate 2 is disposed on a support 3 which can be a translational plate (or rotation). The device 1 can also slide along the projection axis Z with a translation member 50, the latter being shown in Figure 2A.

Thus, the assembly formed by the semi-reflecting plate 24 and the control camera 34 makes it possible to examine the pattern M projected onto the substrate, and to make the necessary adjustments so as to avoid photolithography while the pattern would be poorly positioned or poorly defined on the substrate 2. When the surface of the sample has remarkable points, for example centering points, this adjustment can be performed automatically, the centering points appearing on the control image . The position of the pattern can then be adjusted automatically with respect to these centering points, the support 3 on which the substrate 2 is then motorized.

Between the reflecting plate 24 and the control camera 34, the device may comprise: a filter, referred to as a reflection filter 31, forming an optical density, so as to attenuate the intensity of the light reflected by the reflecting plate 24. to make an image usable by the control camera while the image projected on the substrate is of high intensity.

A diaphragm, referred to as the return diaphragm 32, defining an opening smaller than 10 mm, and for example 5 mm, to limit optical aberrations. The control camera 34 is preferably mounted on a translation stage 35 allowing an adequate positioning of the camera in a plane perpendicular to the return axis X.

Preferably, the optical components located outside the projector, that is to say the semi-reflecting plate 24, and optionally the diaphragm 22 and the band-pass filter 23, are arranged inside a enclosure 21, advantageously light-tight. The chamber 21 opens on a support 27, to which can be fixed, reversibly, a retaining ring 26 holding the objective 25b. This enclosure is preferably tubular, as is the support 27, the latter constituting or being placed at the end of the enclosure 21 facing the substrate 2. The objective 25b is offset by a distance of about 10 cm from the projector 10. As a result, a vibration occurring in the projector, for example under the effect of fans, or the external environment, generates an amplified vibration at the level of the objective 25b due to the offset. This vibration results in a degradation of the spatial resolution of the pattern M formed on the substrate 2. In order to limit this vibration, or even to eliminate it, the inventors have inserted a rigid connection 40 between the retaining ring 26 (or the support 27) and the projector 10. This rigid connection is shown in FIG. 1B. It comprises a support plate 41, on which is fixed the projector 10, the support plate extending parallel to the projection axis Z. The connection also comprises a flange 42, perpendicular to the support plate 41, and connecting the latter to the 27, or the retaining ring 26. This rigid connection limits the inadvertent vibration of the objective 25b and contributes to improving the accuracy of the illumination pattern M projected onto the substrate 2. The control camera 34, as well as the main components of the return path 30 (return filter 31 and return diaphragm 32) are also integral with the support surface 41. The support plate is shown in FIG. 1A, while the support plate 41 and the flange 42 are shown in Figure 1B, showing a side view of the device 1.

Figures 2A and 2B are three-dimensional representations of an example of the device. We find the main components described above. These representations show that the device is compact, the return path components 30 being housed between the objective 25b and the projector 10. FIG. 3A shows an example of a retaining ring 26, intended to hold the objective 25b of the optical system. 25. The retaining ring 26 is tubular, the objective 25b being held inside the tube formed by the ring. The retaining ring is intended to be fixed reversibly on the support 27. The retaining ring comprises at least one magnet 29, disposed on a bearing face 26a of the ring, this face being intended to bear against the support 27, and more specifically on a contact face 27a of said support. The magnet is sufficient to hold the ring 26 in contact with the support 27, the latter being ferromagnetic metal. Several magnets 29 may be disposed on the bearing face 26a, as shown in Figures 3A and 3B.

Preferably, the retaining ring 26 also has an end 26e, called the guiding end, extending perpendicularly to the bearing face 26a, towards the support 27.

The support 27, on which the ring 26 can be fixed in a reversible manner, is of tubular geometry. It defines an opening 27o, in which the guide end 26e is adapted to be inserted, the latter forming a sliding guide inside an inner wall 27i of the support, forming the periphery of the opening 27o, as shown in Figure 3B. The guide end 26e of the ring extends along a distance, called the extension distance, with respect to the bearing face 26a, this distance preferably being greater than 3 mm. Preferably, the extension distance is less than 10 mm. It is for example equal to 5 mm. The inventors have found that such a guide end 26e facilitates the fixing of the ring 26 on the support 27, guiding the positioning of the ring 26 relative to the support 27. The guide end 26e also prevents a fall of the 25b objective in case of accidental snap with a user. Alternatively, the support comprises magnets 29 and the retaining ring 26 is formed, in particular at the bearing face 26a, of a ferromagnetic metal.

According to a variant, the ring comprises a guide end 26e which does not slide along the inner wall 27i of the support 27, but is inserted around an outer wall 27e of the latter, sliding along the latter. The technical effect and dimensions of this guide end are similar to those previously described, the difference is that the guide end does not penetrate into the opening, along the inner face, but slides around the support 27. This variant is represented in FIG. 3C.

Preferably, the contact face 27a of the support and the bearing face 26a of the ring may comprise magnets, so as to define one or more pairs of magnets. Each pair of magnets comprises a magnet disposed on the contact face of the support 27a and a magnet disposed on the bearing face 26a of the ring, the magnets of the same pair having an opposite polarity. The inventors have found that this facilitates the removal of the ring 26 from the support 27, under the effect of a shearing force of the ring 26 relative to the support 27. Preferably, several pairs of magnets can be provided, in particular being arranged in a regular angular pitch. The fact of using one or more pairs of magnets makes it possible to use any solid materials to form the ring 26 or the support 29. This variant is represented in FIG. 3D.

In each of the configurations described in FIGS. 3A to 3D, the bearing face 26a of the retaining ring 26 and the contact face 27a of the support 27 are annular.

It should be noted that the configurations described above in connection with FIGS. 3A to 3D are not limited to the photolithography device 1 described above, and can be applied to another device having a support on which can be fixed a goal. They allow a particularly easy connection of a holding ring, carrying the lens, on a support. The removal of the ring is also very simple.

4A and 4B respectively represent an I-picture _f formed by a projector 10, of dimensions 13 mm x 7 mm, and the projected image _p on the surface of a substrate using the device described above. The image I _f formed by the projector comprises an illumination pattern, representing, under two different scales, the map of France and the boundaries delimiting the regions. This map is found on the image _p projected on the substrate, the scale of dimensions being indicated in FIG. 4B. In this example, a focus lens whose magnification is x2.5 has been used; the projected image on the substrate having a dimension of 5.4 mm * 3 mm. This shows the ability of the invention to achieve, with simple and inexpensive material, photolithography at a high spatial resolution. The illumination pattern projected onto the substrate corresponds to the light areas of the image, that is to say the boundaries of the regions. It is then possible to carry out an etching, in particular a wet etching, this etching being performed only on the illuminated portions of the surface of the substrate, representing the boundaries of each region, following the degradation of the resin under the effect of this illumination.

The invention can be applied in the production of components for microelectronics, micromechanics and microfluidics, in series production applications or for the production of prototyping.

Claims

1. A photolithography device (1) comprising:

an image projector (10), adapted to receive a digital setpoint (l _n ) and to form a two-dimensional image (I _f ), representative of the digital setpoint, the two-dimensional image defining an illumination pattern (M);

a focusing optics (25) capable of projecting the image (I _f ) formed by the projector (10) onto the surface (2s) of a substrate (2) arranged in a focal plane of the optics of focusing, so as to project the illumination pattern (M) on the surface along a projection axis (Z), the focusing optics comprising a lens (25b) integral with a retaining ring (26);

a support (27), on which the retaining ring is adapted to be fixed in a reversible manner; an optical deflecting (24) arranged between the projector (10) and the focal plane of the focusing optics (25), adapted to send a so-called image control (l _c), representative of the pattern projected onto the surface ( 2s), along a return axis (X), intersecting the projection axis; a camera (34) disposed along the return axis and adapted to acquire the control image; the device being characterized in that it comprises an enclosure (21), extending from the image projector (10) along the projection axis (Z), to the support (27) receiving the compression ring holding (26), the enclosure (21) enclosing the deflection optics (24), the device also comprising a rigid holding element (40) extending outside the enclosure, between the projector (10) ) and the support (27) or between the projector and the retaining ring (26).

2. Device according to claim 1, wherein the return optics (24) comprises a semi-reflective plate inclined relative to the projection axis (Z).

3. Device according to any one of the preceding claims, wherein the focusing optics (25) comprises a tube lens (25a) coupled to a lens (25b), in particular an infinity-corrected lens, the optics the deflector (24) being disposed between the tube lens and the lens.

4. Device according to claim 1, wherein the support (27) or the retaining ring (26) comprises at least one magnet (29) so as to ensure a reversible attachment of the ring to the support.

5. Device according to claim 4, wherein the retaining ring comprises a bearing face (26a), adapted to be fixed to the support (27), and a guide end (26e). extending from said bearing face, along the axis of projection, said guide end being adapted to be inserted into the support (27) or around the support.

6. Device according to any one of the preceding claims, wherein the focusing optics (25) is configured such that the image projected onto the surface of the substrate has an area of less than 100 cm ² or 10 cm ² or 2 cm ² .

7. Device according to any one of the preceding claims, comprising a diaphragm (22) disposed between the optical return (24) and the objective (25b).

8. Device according to claim 7, wherein the diaphragm (22) is disposed at a distance from the objective (25b) less than 10 mm or less than 5 mm.

9. A method of photolithography of a substrate comprising the following steps:

a) applying a photoresist to a surface (2s) of the substrate (2);

b) providing said surface of the substrate in the focal plane of the focusing optics (25) of a photolithography device (1) according to any of the preceding claims;

c) transmitting a digital instruction (l _n ) into the image projector (10) of said photolithography device (1);

d) activating the image projector (10), so as to project on the substrate a projection image (l _p ) representative of the setpoint, the projection image defining an illumination pattern (M);

e) acquisition of a control image ( _1c ) by the control camera (34) of the photolithography device (1);

The method of claim 9, comprising, depending on the control image:

a relative displacement of the substrate (2) with respect to the photolithography device

(D;

and / or an adjustment of the focusing optics of the photolithography device.