TWI364629B - Apparatus and method for photolithography - Google Patents

Description

1364629 101. On the 13th of February, the company is replacing the sixth invention. The invention relates to a laser light precision processing device and a method thereof, and more particularly to a laser light micro-shadow making device. method. [Prior Art] [0002] With the development of semiconductors, precision optics, and high-tech technologies such as nanomaterials, the processing technology used for these precision components is also changing rapidly. Laser precision machining technology is becoming more and more widely used in industrial processes. Because of the high monochromaticity, high coherence, and high directivity of laser light, the use of laser light to process components can achieve sub-wavelengths and long-order structures. Laser lithography is a laser light processing technique in which a coherent light beam is obtained by an optical interference element or a diffraction element, which interferes or diffracts on the workpiece to form interference fringes or windings on the workpiece. Shoot the pattern. Finally, the workpiece is subjected to exposure processing to obtain a detailed feature of the nanometer order size. Referring to the first figure, a conventional laser lithography apparatus 10 includes a light source 100, a light splitting element 102, two reflective elements 104, 106, and a light substrate 108. The light source 100 emits an initial beam 10a, and the initial beam 10a is incident on the spectroscopic element 102. The spectroscopic element 102 has a splitting function to divide the initial beam 10a into a first sub-beam 10b and a second sub-beam 10c. The first sub-beam l〇b is directly incident on the illumination substrate 108; the second sub-beam 10c is reflected by the reflective elements 104, 106 and then directed onto the illumination substrate 108. Thereby, the first sub-light East 10b and the second sub-beam 10c interfere on the illumination substrate 108 to form a photo lithography. [0004] The first sub-beam 10b and the second sub-beam 10c are obtained on the illumination substrate 108. 09412923^Single number A〇101 Page 4/29 pages 1013052258-0 1364629 [0005] [0007] [0007] 10Ϊ年.02月13日修正_Page to the intensity of the interfering light lithography stripes can be expressed as: Μ«(1) (1) where ^, ^ are the first sub-beams 1〇b, second The intensity of light at the illumination substrate 108 when the sub-beams are transmitted separately: called the ^12 interference term', which is explicitly expressed as:] wood β^·2 part network: WSi^ (2) (2) where ^; The difference between the angle between a sub-beam 1〇b and the second sub-beam 1〇 (relative to the illumination substrate 108; g丨 is the phase difference, indicating that the first sub-beam 10b and the second sub-beam i〇c are on the illumination substrate 1〇 The difference in light wave position at 8 can be expressed as: [0009]

(3) In the formula (3): _ is the wavelength of the light emitted by the light source 100, and j represents the optical path difference of the first sub-beam 10b and the second sub-beam i〇c at the illumination substrate 108: (:巧·θ...j" indicates the initial phase difference of the light wave of the first sub-beam l〇b and the second sub-beam l〇c” 09412923^"^^^* A0101 Page 5 of 29 1013052258-0 1364629 101. On March 13th, the replacement page [〇〇11] The above-mentioned laser lithography apparatus 1 分为 divides the initial beam 10a into first and second sub-beams l〇b, 10c' in a minute-amplitude manner so that the The two sub-beams form interference fringes on the illumination substrate 108. [0012] Referring to the second figure, the light intensity distribution of the interference fringes formed by the laser lithography apparatus on the illumination substrate 1 〇 8 is shown as a stripe pitch [ 0013] ΔΆ. (4) [0014] (4)

The wavelength of light east is the interference convergence angle, indicating the opening angle of the first sub-beam 10b and the second sub-beam l〇c with respect to the illumination substrate 1〇8. [0015] The light intensity of the interference fringes is expressed as: [0016]

COS 2 (5) [〇〇17] (5) where:): indicates the interference of the first sub-beam and the second sub-beam i〇c at the light of 0, and the relative optical path difference on the substrate 108 is zero. The light intensity of the stripe, ^ represents the 丨/2 of the phase difference of the first sub-beam l〇b' the second sub-beam l〇c at a certain position on the illumination substrate 108. [0018] It can be seen from equation (5) that the light intensity distribution of the interference fringes is the square of a cosine function, so that the interference fringes of the respective interference stripes are substantially the same. 094129231^^^ A〇101 Page 6 of 29 1013052258-0 1364629 On February 13, 101, press the page. [0019] Only by (5), the maximum value of light intensity 纟· can be expressed as : I讹ώΐ [0020] 7; (6) max ϋ [0021] The light intensity / the minimum value. / · can be expressed as

^ WZK

[0022] · : ι· . A 0 (7) [0023] However, in the actual interference process, the beam will also produce diffraction at the same time, so that the light intensity maximum value κα 明 of the bright stripe is less than ..r, K. The light intensity of the dark stripes is extremely small _f·. Greater than zero, the light intensity distribution of the interference fringes is not high, and the contrast is not high, and the sharp detail features cannot be formed in the process of photolithography. SUMMARY OF THE INVENTION [0024] In view of the above, it is necessary to provide a laser light lithography fabrication apparatus that can form fine laser light lithography between light and dark. [0025] In addition, it is also necessary to provide a method of fabricating laser light lithography, which can be used to obtain fine laser light lithography between light and dark. A laser light lithography apparatus comprising a light source, an optical interference device, an optical convergence device, and a light substrate. The light source emits a light beam, the optical interference device divides the light beam into a plurality of coherent light beams and interferes to form an interference beam, the optical convergence device converges the interference beam, the illumination substrate receives the concentrated beam, and records the convergence of the concentrated beam onto the illumination substrate. 094129231^单单A〇101 Page 7./29 pages 1013052258-0 1364629 101. February 13' day nuclear replacement page pattern feature, wherein the optical interference device comprises a first light transmitting element and a first a light-transmitting element, the light beam entering the optical interference device, passing through the first light-transmitting element to the second light-transmitting element, wherein at least part of the light beam is reflected by the second light-transmitting element and is in the first and second light-transmitting elements Reflected back and forth to form a coherent beam. [0027] A method for fabricating laser light lithography, comprising the steps of: [0028] generating a light beam by a light source; [0029] providing an optical interference device, the optical interference device comprising a first light transmissive element and a second transparent a light element, after entering the optical interference device, is incident on the second light transmissive element through the first light transmissive element, wherein at least part of the light beam is reflected by the second light transmissive element and between the first and second light transmissive elements Reflecting back and forth to form a coherent light beam; [0030] dividing the beam into a plurality of coherent beams by the optical interference device; [0031] causing the coherent beams to interfere with each other to form an interference beam; [0032] providing a beam convergence device; 0033] concentrating the interference beam by the beam convergence device to form a concentrated beam; [0034] providing a light substrate to receive the concentrated beam; [0035] recording, by the illumination substrate, a pattern formed by the concentrated beam projected on the illumination substrate message. Compared with the prior art, the apparatus for producing laser lithography of the present invention and the method thereof provide an optical interference device capable of dividing incident light into a plurality of phases 094129231^single number A〇101 page 8/total 29 pages 1013052258-0 1^04629 .yx 10 Ϊ. On February 13th, the shuttle is drying the beam and coherent interference occurs, and finally a laser lithography is formed on the illumination substrate. [Embodiment] [0037] Referring to the third drawing in May, a preferred embodiment of the laser lithography apparatus and method thereof of the present invention is disclosed. a laser light lithography device 2 is provided with a laser light source 200, a collimating lens 2〇2, a slit interference device 2〇4, a focusing lens 206 and a light substrate 2〇8 in this order along the optical path. The optical axes of the components are on the same line. [0038] The laser light source 200 can emit a laser light 2〇a, and the laser light 2〇a has the characteristics of high chromaticity and high coherence, and its spectral width and spectral width are extremely small. This high coherence ensures that the laser light 2〇a remains stable after being converted by other optical components. Thus, such high chromaticity and high coherence provide excellent conditions for generating coherent interference. The slit interference device 204 is composed of a plurality of light-transmissive slits 2〇4a and a light-blocking portion 204b which are spaced apart from each other and the light-transmitting slits 2〇4a and the light-blocking portions 204b are equally spaced. The slit width of the light-transmitting slit 204a is a, and the width of the light-blocking portion 204b is b (see the fourth figure). The light-transmitting slits 2〇4a allow the light beam incident thereon to pass unimpeded, and the light-blocking portions 2〇4b completely block the light beam incident thereon. Thus, the slit interference device 2〇4 can divide an incident beam into a series of sub-beams. Since the series of sub-beams 2〇e are divided by the same beam, they have the same optical frequency g and wavelength -jj, which satisfy the requirements of coherent light. [0040] 094129231^^^^ The illumination substrate 208 has a photosensitive property, which can record and retain the beam formed on the correction replacement page of the A0101 page 9/29 page 1013052258-0 1364629 101. Light and dark variations, forming a laser lithography. [0041] When the laser lithography apparatus 20 is in operation, the laser light source 200 emits a laser beam 20a which is collimated by the collimator lens 202 into a parallel beam 20c and incident on the slit interference means 204. Since the slit interference means 204 has a splitting function, the parallel beam 20c is divided into a plurality of coherent sub-beams 20e. The coherent sub-beams 20e interfere with each other and then converge via the focusing lens 206 to form an interference beam 20f. The interference beam 20f is irradiated onto the illumination substrate 208 and forms an interference lithography pattern thereon. [0042] Referring to the fourth figure, the optical path difference formed by the light beams transmitted by the adjacent two slits on the illumination substrate 208 is expressed as: [0043] : A = fa ^ b) sine (8) [0044] ( In the formula 8), $ denotes the width of the light-transmitting slit 204a, and ^^ denotes the width of the light-blocking portion 204b between the light-transmitting slits 204a, which indicates the corresponding direction angle when the adjacent slits form interference fringes. . [0045] The phase difference of the light waves that are incident on the illumination substrate 208 by the light beams passing through the adjacent slits is expressed as: (9) '2τι 2ττ d = —A = —(a^b)-sin9 λ λ ' [ 0047] In the formula (9), * j is the wavelength of the light wave * g is the corresponding direction angle when the stripe is involved. For the adjacent two slits, the dry form is 09412923. The order number is A101. Page 10/29 pages 1013052258-0 1364629 * tt · February 13, 101 nuclear replacement page [0048] by Fourier optical theory, narrow The light wave complex function table 7F formed by the interference beam 20f formed by the slit interference device 204 having a slit number N on the illumination substrate 208 is

[0049] sm Ν·αχ. n(a+b)x0 smc\ ?ζ sin π·(α+Β)·χ0 Άζ (10): is an imaginary unit [0050] where & is a light-transmissive slit 204a The slit width is the distance between the slit interference device 204 and the illumination substrate 208. The distance between the interference fringes and the central bright stripe of the illumination substrate is a tilt factor related to the direction angle, which is expressed as: [0051] when θ = 0 〇when: (11) [0052] The light intensity distribution function table formed by the interference beam 20f formed by the slit interference device 204 having the number of transmission slits N on the illumination substrate 208 is obtained by the equation (10). , which can be expressed as: 09412923 production order number A〇101 page 11 / total 29 page 1013052258-0 1364629 [0053] 101 years 0' February 13' day nuclear replacement page, 2 · [U(k)J = .l0 sine 2 axt sm Νδ Ύ 2 λζ • δ sin —\ 2 (12) [0054] In addition to coherent interference, the interference beam 20f also undergoes diffraction, which will eventually form on the illumination substrate 208. The intensity distribution of the interference fringes on the upper surface has an influence. (12) where Λ denotes the disturbance of the coherent interference pattern when the coherent light beam such as sine 2 ?\z is diffracted. Factor, called diffraction factor. [0055] The light intensity distribution function of the interference fringes formed by the slit interference device 204 having the slit number N on the illumination substrate 208 can be expressed by the formula (12), which can be expressed as: [0056] 2(13) Referring to the fifth figure, when N = 5, the intensity distribution pattern of the interference fringes, in the figure, there are (N-1) dark stripes between the two adjacent bright stripes to form bright stripes. background. The opening angle of the incident beam corresponding to each bright stripe sin ΝύΊΓ. sm δ Ί 09412923 One-Order No. Α〇101 Page 12/Total 29 Page 1013052258-0 1364629 .-- 101 years. February 13th revised replacement page [0058] δΘν = __N(a+b)cosdK. (13) [0059] It can be seen from the formula (14) that the larger the number N of the light-transmissive slits of the slit interference device 204, the opening angle of the bright stripe; The smaller, the finer the interference fringes. From υΝ, by setting the appropriate number of light-transmissive slits, light lithography with sharp and fine features can be obtained. Please refer to a sixth diagram which discloses another preferred embodiment of the laser light lithography apparatus of the present invention and a method thereof. A laser lithography device 30 is sequentially provided with a laser light source 310, a collimating lens 320, a beam interference device 330, a focusing lens 340, and a illuminating substrate 350 along the optical path, and the optical axes of the components are on the same line. . [0061] The laser light source 310 emits a laser light 30a having high chromaticity and high coherence, and its spectral width and spectral width are extremely small. This high coherence ensures that the spectral width and spectral width of the laser light 30a are maintained within a very small range after being transformed by other optical components. Thus, such high monochromaticity and high coherence provide excellent conditions for generating coherent interference. [0062] The beam interference device 330 includes first and second interference components 331, 332. Referring to the seventh figure, the first interference component 331 has an incident surface 331a, a 09412923^ single number A 〇 101 page 13 / a total of 29 1 1013052258-0 1364629 101 years 0-month IB day shuttle is replacing the page surface 331b; The two interference components 332 have an incident surface 332a and an exit surface 332b. The exit surface 331b and the incident surface 332a are optical transflective surfaces and are parallel to each other. The light beam incident on the interference element 331 is refracted by the incident surface 331a and then emitted by the exit surface 331b; and then reflected back and forth between the two half-transparent surfaces 331b, 332a to form a series of sub-beams. The series of sub-beams are divided by a beam of light, and the optical frequency and the wavelength j of the light are the same, thereby forming coherent light. After a series of sub-beams have coherent interference, they exit through the exit surface 332b to form a coherent light beam. [0064] The illumination substrate 350 has a photosensitive property that records and preserves the light and dark variation characteristics of the light beam incident thereon to form a laser lithography. When the laser lithography apparatus 30 is in operation, the laser light source 310 emits a laser beam 30a which is collimated by the collimating lens 320 to form a parallel beam 30b and is incident on the beam interference means 330. Due to the back and forth reflection of the beam between the first interference component 331 and the second interference component 332, the parallel beam 30b is divided into a series of coherent sub-beams 30d. The sub-beams 30d interfere with each other and are then concentrated by the focusing lens 340 to form an interference beam 30e. The interference beam 30e is incident on the illumination substrate 350 and interferes with the lithography pattern thereon. Therefore, the interference phase difference formed between the light-emitting surface 331b and the incident surface 332a of the light beam 30d is expressed as: [0066] 2ττg=---(2nd) λ (15) [00) where 2 is The wavelength of the incident light ^2 is the exit surface 331b, the input 094129231^the single number A〇101 page 14/29 pages 1013052258-0 [0068] 1364629 ε · The refractive index of the transparent medium between the planes 332a , ^ is the outgoing distance - the positive distance between the incident faces 332a. The light intensity distribution of the light and dark stripes formed on the illumination substrate 35A after being focused by the focusing lens 340 can be expressed as: [0069] 2 (16) l-2r2 cos δ+r [0070] (16) where the incident light 3 is represented The light intensity of 〇3 broadly indicates the amplitude reflectance of the light beam of the transflective surfaces 331b and 332a, and the valley: the phase difference shown by the formula (15). [0071] Referring to the eighth figure, the "strip half width" for measuring the precision of the stripe is defined as the distance between the two points at which the stripe light intensity on both sides of the stripe light intensity peak drops to 1 / 2 of the ridge value. From (16), when j is /, you can get: [0072]

(17) where 'and' indicates the light intensity reflectance of the light transmissive surfaces 331b and 332a to the light beam, and the definition is expressed as::. [0074] See (17), the larger the value of $; the smaller the value, the reflected 094129231^^^ Α0101 page 15 / 29 pages 1013052258-0 1364629 101 years 0' February 13 shuttle The positive replacement page is the half width of the stripe, and the finer the stripe. When $ = 2, the sharpness of the interference fringe is highest. Thus, by setting an appropriate light intensity reflectance of $, a contrast-precision, extremely high-precision lithography can be obtained. [0075] In summary, the present invention complies with the requirements of the invention patent, and submits a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and those skilled in the art will be able to include the equivalent modifications or variations in the spirit of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0076] The first figure is a schematic diagram of a conventional laser light lithography apparatus; [0077] The second figure is a schematic diagram of the intensity distribution of laser light lithography formed by a conventional laser lithography apparatus [0078] The third diagram is a schematic diagram of a preferred embodiment of the laser lithography apparatus of the present invention, and the fourth diagram is a schematic diagram of a slit interference element of the laser lithography apparatus of the third diagram; [0080] FIG. 5 is a schematic diagram showing an interference fringe intensity distribution obtained by the illumination substrate of the laser photolithography device of the third embodiment; [0081] FIG. 6 is another preferred embodiment of the laser photolithography device of the present invention FIG. 7 is a schematic diagram of a beam interference device of a laser lithography apparatus of FIG. 6; 〇94129231^单编号除1第16页/29 pages 1013052258-0 1364629 • ', , 101. February 13th Nuclear Replacement Page [0083] The eighth figure is a half-width schematic diagram of one of the interference fringes obtained from the illumination substrate of the laser light lithography apparatus of the sixth figure. [Description of main component symbols] Light source: 100, 200, 310 [0085] Spectroscopic element: 102 [0086] Reflecting element: 104, 106 [0087] Illuminating substrate: 108, 208, 350 [0088] Optical collimating device : 202, 320 [0089] Interference device: 204, 330 [0090] Light-transmissive slit: 204a [0091] Light-blocking portion: 204b [0092] First interference component: 331 [0093] Second interference component: 332 [ 0094] Incident plane: 331a, 332a [0095] Exit surface: 331b, 332b [0096] Optical focusing device: 206, 340 [0097] Light source emits light beam: 10a, 20a, 30a [0098] First sub-beam: l〇b [0099] Second sub-beam: 10c [0100] Collimated beam: 20c, 30b 0941292# single number A0101 1013052258-0 page 17 / 29 pages 1364629 101. February I3 · Japanese nuclear replacement page [0101] [0103] Coherent light beam: 20e, 30c Interference beam: 20f, 30d Focused beam: 30e 09412923 Production order number A〇101 Page 18/29 pages 1013052258-0

Claims (1)

1364629 • i, a 101 years. February 13th, the shuttle is replacing page 7. Patent application scope: 1. A laser light lithography apparatus comprising: a light source to generate a light beam; an optical interference device to The light beam is divided into a plurality of coherent light beams, and the coherent light beams interfere to form an interference light beam, wherein the optical interference device comprises a first light transmitting component and a second light transmitting component, and the light beam enters the optical interference device and passes through the first through The light element is incident on the second light transmitting element, wherein at least part of the light beam is reflected by the second light transmitting element and reflected back and forth between the first and second light transmitting elements to form a coherent light beam; an optical convergence device to The interference beam converges to form a converging beam; a light substrate is used to receive the converging beam and record the pattern message formed by the converging beam projected onto the illumination substrate. 2. The laser photolithography apparatus of claim 1, wherein the optical interference device comprises a slit interference device. 3. The laser photolithography apparatus of claim 2, wherein the slit interference device is provided with at least three equally spaced transparent slits. 4. The laser photolithography apparatus of claim 3, wherein the slit interference device further comprises a light blocking portion interposed between the light transmissive slits. 5. The laser lithography apparatus of claim 4, wherein the first light transmissive element and the second light transmissive element have opposite surfaces, the two surfaces being semi-transparent and semi-reverse. 6. The laser light lithography apparatus of claim 5, wherein the opposite surfaces are disposed in parallel with each other. 7. The laser light lithography apparatus of claim 1, further comprising: a beam collimating device for converting the beam into a parallel beam and then emitting the beam to the 09412923, the order number A〇101, page 19 / Total 29 pages 1013052258-0 1364629 On February 13th, 2011, the page was replaced by a positive optical interference device. 8. The laser photolithography apparatus according to claim 1, wherein the photo substrate has a photosensitive property and is capable of retaining a pattern information formed by a light beam irradiated thereon. 9. A method of fabricating a laser lithography, comprising: generating a light beam by a light source; providing an optical interference device, wherein the optical interference device comprises a first light transmissive element and a second light transmissive element, the light beam After entering the optical interference device, the first light transmitting component is incident on the second light transmitting component, wherein at least part of the light beam is reflected by the second light transmitting component and reflected back and forth between the first and second light transmitting components to form a coherent a light beam; dividing the light beam into a plurality of coherent light beams by the optical interference device; causing the coherent light beams to interfere with each other to form an interference beam; providing a beam concentrating device; concentrating the interference beam by the beam concentrating device to form a condensed beam t A light substrate is provided to receive the concentrated beam; and the pattern information formed by the concentrated beam projected on the illumination substrate is recorded by the illumination substrate. 10. The laser light lithography method of claim 9, wherein the optical interference device comprises a slit interference device. 11. The laser light lithography method of claim 10, wherein the slit interference device is provided with at least three equally spaced transparent slits. 12. The laser light lithography method of claim 11, wherein the slit interference device further comprises a light blocking portion interposed between the light transmissive slits. 094129231^单单A〇101 Page 20/29 pages 1013052258-0 1364629 13 101. February 13th, the shuttle replacement page, as described in claim 9, the laser light lithography production method, wherein A light transmissive element and a second light transmissive element have opposite surfaces, and the two surfaces are semi-transparent and semi-reflexive. 14. The method of producing a laser lithography according to claim 13, wherein the opposite surfaces are disposed in parallel with each other. 15. The laser light lithography method of claim 14, further comprising: providing a beam collimating device, the beam being collimated by the beam collimating device into a parallel beam and incident on the optical interference device. The laser light lithography manufacturing method according to claim 9, wherein the light-emitting substrate has a photosensitive property capable of retaining a pattern information formed by a light beam irradiated thereon. 094129231^单号 A_ Page 21 of 29 1013052258-0