TWI299884B - Etching method using photoresist etch barrier - Google Patents

Description

A7 B7 I2998^()91112897 Patent Application Replacement Page (July 1992) V. Invention Description (1) Invention 4 The present invention relates to a method of manufacturing a semiconductor device, and more particularly to the use of A method of etching a photoresist etch barrier formed by exposing a light source having a wavelength in the range of 157 nm to 193 nm, such as an argon fluoride (ArF) laser or a fluorine laser (F2 laser) . Prior Art Description Patterns were formed on substrates having different materials by optical lithography in a semiconductor memory device process. A photoresist polymer is applied to the light layer and selectively exposed by a mask to illuminate the light in the photoresist. The photoresist is then developed to form an etch barrier for etching the target layer, and a predetermined pattern is obtained by etching the layer of the grain. The semiconductor memory device is integrated with the lithography technology. The lithography process is generally carried out using an exposure process and a development process. Recently, lithography processes have generally represented exposure processes, while lithography has been divided into optical lithography or non-optical lithography. The study of optical lithography is carried out in each of the fields of exposure equipment, photoresist materials, masks and processes. In the field of exposure systems, high-order aperture lenses and hardware with a calibration height of 0.6 mm have been developed. Regarding the study of photoresist materials, chemical enlargement can be a representative. Study phase shift masks and light proximity corrections as excellent representatives in the field of masks. Moreover, trilinear resist (TLR), bilinear resist (BLR), upper surface imaging (TSI), and anti-reflective coating (ARC) processes have been developed. The initial exposure apparatus is a contact printer where the mask is in direct contact with a substrate and is visually calibrated by the operator with a direct naked eye view of the mask and substrate. Improves resolution when the gap between the substrate and the mask is reduced, and makes the substrate O:\78\78817-920725.doc/mg - 4 - _________ This paper scale applies to the Chinese National Standard (CNS) A4 specification (210X 297) Mm) A7 B7

12998^4) Chinese Patent Specification Replacement Page 9112118897 (July 1992) V. INSTRUCTIONS (2) Exposure with a proximity printer, such as soft contact or hard contact (less than 1 〇 micron) depending on the gap. In the early 1970s, a projection type exposure apparatus using photons t-reflected or refracted light was developed, and the resolution was improved and the mask was extended. As a result, projection type exposure equipment began to be applied to large substrate products. Development. In the mid-70s of the 19th century, the use of stepper using projection optics began to study the development technology, which helped to mass-produce semiconductors. The stepper is an abbreviation of "stepping and repeating". The stepper's exposure equipment improves resolution and calibration accuracy. In the early stepper, a method of reducing the projection exposure of the mask pattern to the substrate ratio of 5: 丨 or 1〇: i was designed. Due to mask pattern limitations, the 5: 降低 reduced projection exposure method is often used. The "Step and Scan" type scanner was developed in the early 1990s, which reduced the ratio to 4:1. However, the scanner has poor performance in terms of the mask pattern, and on the other hand, when the wafer size is reduced, the scanner can be used as an exposure device to increase manufacturing efficiency, and the application is more regular. The line resolution is extremely large with the light source. Wavelength-dependent. The wavelength of stepper and repeat type stepper has been changed by 436 nm (g-line), 365 nm (i-line), 248 nm order KrF laser (deep ultraviolet, DUV) using g The initial exposure device of the -line (wavelength (λ) = 436 nm) is capable of achieving a 〇·5 micron level pattern, while the exposure device using 丨_line (wavelength = 365 nm) is capable of achieving a 〇.3 micron level pattern. In the DUV optical lithography method using a wavelength of 248 nm, a pattern of 0.8 micron level can be achieved due to the time delay effect and substrate dependence. Therefore, -5-O:\78\78817-920725 .doc/mg paper size Applicable to China National Standard (CNS) A4 Specification (21〇χ297 mm) 1299 Called 4)91 i 12897 Fresh Profit Application Chinese Manual Replacement Page (July 1992) A7 B7 V. Invention Description (3) 0.15 micron pattern, need to develop a wavelength of 193 New DUV optical lithography technology for nano ArF lasers. For i-line and DOF, DUV lithography has excellent resolution, but this technique is difficult to control. Optical problems can be created by short wavelengths, and chemical problems are created by the use of chemically amplified resists. When the wavelength becomes shorter, the critical dimension (CD) is changed by the standing wave, and the reflected light is excessively developed by the phase difference of the substrate. The CD variation of the line width is periodically changed by the incident light and the reflected light, and can also be changed by a small change in the thickness of the photoresist or the base film. Chemicals are needed to increase the sensitivity of the resist in the DUV process. However, there are PED (post-exposure delay) stability, substrate dependence and similar problems associated with the reaction mechanism. It is now developed to form a 0.11 micron pattern using an exposure apparatus using an ArF laser (λ = 193 nm). A major problem with ArF exposure technology is the study of photoresists used in ArF. The photoresist used in KrF basically needs improvement to be used in ArF. However, in the case of using an ArF laser, a photoresist used for KrF such as a COMA (cycloolefin-maleic anhydride) group, an acrylate group polymer type or a mixture type photoresist having a benzene ring structure cannot be used. In the case of using an i-line KrF laser, a photoresist having a benzene ring structure has been used to ensure the resistance to dry etching. When a photoresist having a benzene ring structure is used under an ArF laser, since light absorption increases at 193 nm (which is an ArF laser wavelength), light permeability is lowered, so that it is impossible to make the photoresist lower. Side exposure. Further, when the ArF lithography technique is utilized using a photoresist containing a benzene ring therein, the photoresist pattern is deformed. Moreover, the photoresist pattern is concentrated on one side in the etching process. For example, in the etching process, the stripe formed by exposure with an ArF laser is O:\78\78817-920725.doc/mg - 6 - This paper scale applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm). ) 1299884 A7

The type of photoresist pattern is deformed. The deformation of the light pattern formed by exposure with an ArF laser also occurs in an etching process in which contact holes are formed. Therefore, with the limitation of photographic technology, it is impossible to obtain contact holes having a critical size of micrometers or less with a photoresist pattern. Therefore, photoresists which do not have a benzene ring, ensure dry etching resistance, have good adhesion and can be developed with 2.23% TMAH have been developed. 1A through 1D are diagrams showing a method of forming bit line contact holes by ArF lithography techniques according to the prior art. Fig. 1 shows the arrangement of the active layer n, the word line 12, the bit line 13, and the bit line contact plug between the active layer 丨丨 and the bit line. Fig. 1B is a cross-sectional view taken along line X-X of Fig. 1A; showing a bit line 13 formed in accordance with the prior art. In Fig. 1B, reference numerals, 1 〇, indicate substrates, and '151 and '16' represent insulating interlayers. As shown in the figure, the bit line contact plug 14 is exposed after the bit line 13 is formed due to the critical size limitation. Further, as shown in Fig. 1C, the damage generated during the etching process for forming the bit line π can form the lower cut 18. The exposed bit line contact plug 14 is also damaged during the etching process for forming the bit line 13. Therefore, a trench τ is formed in the contact plug 14, which is filled with the insulating layer 19, so that it is in the insulating interlayer 19 A void V is formed. The bit line 13 may be short-circuited by the gap V and other conductive lines, and the contact resistance may increase due to the insulating layer 19 filled in the trench. As described above, it is not easy to reduce the critical dimension of contact holes, and therefore a method of fluidizing the photoresist pattern at a high temperature is required to define a contact region having a reduced critical dimension, but the method causes another burden, that is, Make the standard paper size applicable to China National Standard (CNS) M specification (21〇x 297 mm) 1299884

The photoresist pattern of the cover contacting the adjacent regions of the holes is thinned. Therefore, even if a method of fluidizing the photoresist pattern is used, the critical dimension of the contact hole is still limited to nano. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a light source (such as an argon fluoride (ArF) laser or a fluorine laser (F2 laser)) that is capable of preventing wavelengths in the range of 匕7 nm to 193 nm. A method of deforming a formed photoresist pattern. One aspect of the present invention provides a method of etching using a photoresist pattern as an etch barrier, the method comprising the steps of: applying a photoresist layer on a seed etch layer, After exposing the photoresist layer to a light source having a wavelength in the range of 157 nm to 193 nm, the photoresist layer is developed to form a photoresist pattern; a polymer layer is formed, and at the same time, fluorine is used. a mixture of a base gas, an Ar gas, and a helium 2 gas is partially engraved with the dry etching layer, wherein the fluorine-based gas is CXFy or CaHbFc, and wherein the χ, y, a, 13 and (: respectively at i Within the range of 1 ;; and using the polymer layer and the photoresist pattern as the etch mask to etch the etched layer. The method may further include the photoresist pattern after or before the step of forming the polymer layer The step of hardening. The step of fluidizing the photoresist pattern may be further included prior to forming the polymer layer step. BRIEF DESCRIPTION OF THE DRAWINGS The following description of the preferred embodiments and the accompanying drawings, the above and other objects of the present invention And the features will be apparent, wherein: Figures 1A to 1D show the formation of contact -8- according to the prior art using ArF lithography technology. The paper is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1299884 A7 — _ —_B7 V. DESCRIPTION OF THE INVENTION (6) Method diagram for holes; FIGS. 2A to 2D are cross-sectional views showing a method of forming a contact by ArF lithography according to a first embodiment of the present invention; FIG. 3A to FIG. Is a cross-sectional view showing a method of forming a contact by ArF lithography according to a second embodiment of the present invention; FIGS. 4A to 4F are cross-sectional views showing ArF lithography according to a third embodiment of the present invention. The technique forms a method of contact; and FIG. 5 is a plot showing the critical dimension of the photoresist pattern according to different temperature changes. Fortunately, the detailed description of the specific embodiment will be described in detail hereinafter with reference to the accompanying drawings. A method of preventing deformation of a photoresist pattern formed by exposure of a light source having a wavelength in the range of 157 nm to 193 nm, such as an argon fluoride (ArF) laser or a fluorine laser (?2 laser). 2A to 2D are cross-sectional views showing a method of forming contact holes according to a first embodiment of the present invention. Referring to Fig. 2A, a gate electrode 2 as an example of an adjacent conductive pattern is first formed on a semiconductor substrate 2? A hard mask 22 and a liner 23 are formed on the upper surface and the sidewall of the electrode, respectively, and then an insulating interlayer 24 is formed on the semiconductor substrate 20. The hard mask 24 prevents the gate during the subsequent self-aligned contact etching process The electrode is damaged. In a preferred embodiment of the invention, the hard mask and the lining are formed of a nitride layer, and the insulating interlayer is composed of an oxide of a higher planarization layer, borophosphonate (BPSG), spin coating Formed by a glass (s〇G), a high density plasma oxide or a nitride layer.

After Ik, a photoresist is applied to the insulating interlayer 24, and is used by the wave -9 - sheet scale for the wealth of the home (CNS) X 297 public) 1299884 A7 _______ B7 V. Description of invention (7) —""" Long exposure of light sources in the range of 157 nm to 193 nm forms a photoresist _ case, such as the use of ArF lasers or 匕 lasers. In a preferred embodiment of the invention 'in order to form the photoresist pattern 25, a coating of c〇ma (cyclo-glycol-maleic anhydride) or a propionate-based resist is achieved at about 5 angstroms. To the thickness of the range of about sen (eight) angstroms. S. Fig. 2B forms a polymer layer 26 on the photoresist pattern with a plasma generated from a mixture of fluorine and oxygen, and then forms a hardened photoresist pattern 25 by using Ar, and a polymer-layer 26 is made of fluorine. Based on gas (such as CxFy or CaHbFc, where -X, y, a, b, and 〇 are in the range of 1 to 10, respectively), F2 gas and 〇2 gas produced oxygen and fluorine plasma in about ^^ It is formed at a temperature of about 8 〇t. At this point, the gas is supplied at a rate of from about 1 seem to about 5 seem. To improve the etching resistance, the hard photoresist pattern 25' is formed by Ar plasma treatment or cardiac ion implantation. Ar plasma treatment is carried out at a low pressure of from about 1 milliTorr (mTorr) to about 1 Torr and a high power of from about 500 watts to about 2 watts. The ion implantation is carried out by injecting Ar ions at a dose ranging from about 1 〇 1 〇/cm 3 to about 丨〇 1 " cm 3 and an energy in the range of 1 千 volts to 300 keV. Therefore, the resist pattern can be prevented from being deformed by forming a hardened photoresist pattern under low pressure and high power conditions. Referring to FIG. 2C', the dielectric layer 26 and the hardened photoresist pattern are used as an etch mask to etch the insulating interlayer 24 to form a surface contact between the liner 23 and the adjacent semiconductor substrate 20 between the gate electrodes 2 Hole 27. The semiconductor substrate 1〇 is maintained at a constant temperature and a fluorine-based gas (CxFy^CaHbFc, wherein X, y, a, b, and c are respectively in the range of 1 to 10) in the process of forming the contact hole 27. - This paper size applies to the S National Standard (CNS) A4 specification (210 X 297 mm) 1299884 A7 - 1 ' ... _B7_ V. Invention Description " --- 10 (dry) and Ar gas generated plasma After the etching process, a cleaning process is performed to remove by-products, such as a polymer. Figure 2D, removing the polymer layer 26 and the cured photoresist pattern. By the first embodiment of the present invention, it is prevented A photoresist pattern formed by exposure of a light source having a wavelength in the range of 157 nm to 193 nm is deformed by hardening a photoresist pattern on which a polymer layer is formed. Figures 3A to 3E show a second specific embodiment according to the present invention. DETAILED DESCRIPTION OF THE INVENTION A cross-sectional view of a method of forming a bit line using A lithography technique. Multi-Picture _3 A, forming an insulating intermediate on a semiconductor substrate 30 on which an active layer 3 (eg, source or drain) is formed Layer 32. Subsequently, the insulating interlayer 3 2 is selectively etched to form an exposed active layer 3 The hole is contacted, and then a conductive layer is formed on the semiconductor substrate 30. The process of flattening the conductive layer is performed to expose the surface of the insulating interlayer 32 to obtain a bit line contact plug which contacts the active layer 31 through the contact hole. Plug 33. Subsequently, an insulating interlayer 34 is formed between the insulating interlayer 32 and the bit line contact plugs 33. In a preferred embodiment of the invention, the conductive layer is grown by selective epitaxial growth of a single crystal layer or The polysilicon layer is formed, and the insulating interlayer 34 is formed of an oxide of a high-level planarization layer, a borophosphonium S's salt (BPSG), a spin-on glass (S0G), a high-density plasma oxide or a nitride layer. 3B, a photoresist pattern 35' is formed on the insulating interlayer 34 by exposure to a light source having a wavelength in the range of 157 nm to 193 nm (such as an ArF laser or F2 laser) and the photoresist pattern is formed. 35 hardening to improve etching resistance. In a preferred embodiment of the invention, the photoresist pattern 35 is formed of a c〇ma (cycloolefin-maleic anhydride) family or an acrylate group resist. Pattern-11 - This paper scale applies to China National Standard (CNS) A4 Specification (210X297 mm) A7 B7 12998^^^2897 Patent Application Chinese Manual Replacement Page (July 1992) V. Invention Description (9) 35 is hardened by Ar ion implantation or electron beam injection. If electron beam injection is used The photoresist pattern may shrink, so an electron beam with appropriate energy needs to be implanted. In a preferred embodiment of the invention, the injected electron beam has a wavelength of from about 400 microcoulombs/cm to about 4000 microcoulombs/cm3. Range of Energy. Referring to Figure 3C, a polymer layer 36 is then formed to a thickness of from about 5 angstroms to about 5 angstroms while partially insulating the intermediate layer 34. To form the polymer layer, from about 10 sccm to about 2 〇sccm is supplied at a pressure of from about 10 Torr to about 50 mTorr at a power of from about 500 watts to about 2 watts for about 1 sec to 60 seconds. a gas based on about 100 sccm to about 1000 8 (a gas of about 111 cm and about i sccm to about 5 sccm 〇 2 gas. The gas based on it is CxFy or

CaiibFc, wherein x, y, a, b & c are in the range of 1 to 1 分别, respectively. The critical dimension of the contact holes can be reduced by the thickness of the polymer layer 36. The hardened photoresist pattern 35 covered by the mask 3D layer 36 serves as a mask (4) insulating interlayer 34 to form contact holes 37 which expose the bit line contact plugs. Subsequently, the photoresist pattern 35 and the polymer layer % are removed. Referring to Fig. 3E, a bit line 38 is formed which is connected to the bit line contact plug by contact holes 37. In a preferred embodiment of the invention, bit lines 38_, Ti or Co are formed. By forming the fine pattern and improving the reliability of the second embodiment of the present invention, after the photoresist pattern is hardened, it can be formed on the photoresist pattern formed by exposure of the light source having a wavelength in the range of 157 nm to 193 nm. Polymer layer.

4A through 4F are cross-sectional views showing a method of forming a bit line by ArF lithography in accordance with a third embodiment of the present invention. Referring to FIG. 4A, a semiconducting O is formed therein (eg, source or drain) O:\78\78817-920725.doc/mg

1299884 A7 _______B7 V. DESCRIPTION OF THE INVENTION (10) An insulating intermediate layer 42 is formed on the bulk substrate 40. Subsequently, the insulating interlayer 42 is selectively etched to form contact holes exposing the active layer 4, and then a conductive layer is formed on the semiconductor substrate 40, and fabrication for planarizing the conductive layer is performed until the insulating interlayer 42 is formed. The surface is exposed to obtain contact with the active layer 4 1 through the contact holes. Subsequently, an insulating interlayer 44 is formed on the insulating interlayer u and the bit line contact plugs 43. In a preferred embodiment of the invention, the conductive layer is formed by selective epitaxial growth of a single crystal germanium layer or a polycrystalline germanium layer, and the insulating intermediate layer 44 is composed of an oxide of an advanced planarization layer, borophosphonate ( BPSG), spin-on glass (s〇G), high density plasma oxide or nitride layer formation. Referring to Fig. 4B, a photoresist pattern 45 is formed on the insulating interlayer 44 by exposure with a light source having a wavelength in the range of 157 nm to 193 nm (e.g., an ArF laser or an F2 laser). The photoresist pattern 45 defines a critical dimension to contact the holes to expose a contact area. In a preferred embodiment of the invention, the photoresist pattern 45 is formed of a COMA (cycloolefin-maleic anhydride) family or an acrylate family resist. Referring to Figure 4C, a fluidization process is now performed to reduce the critical dimension of contact holes from d1 to d2. The fluidization process is carried out using a hot plate, oven or uv baking at a normal pressure of from about 100 ° C to about 220 ° C for from 1 minute to 3 minutes. Referring to Fig. 4D, a polymer layer 46 is formed on the photoresist pattern *5 subjected to the mashing process to reduce the critical dimension of contact holes from d2 to those. To form the polymer layer, from about 5 Torr to about 2,000 watts, at a pressure of from about 10 mTorr to about 5 Torr, from about 5 sccm to about 2 〇 sccm of fluorine-based gas, about 100 Seem to about 1〇〇〇sccmiAr gas and about 1 seem -13- This paper scale applies to Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1299884 A7 B7 V. Invention description (11) to about 5 seem 〇 2 gas. A fluorine-based gas in which X, y, a, b, and c are each in the range of 丨 to 1 。. The photoresist reliability can be improved by protecting the photoresist pattern 45 subjected to the fluidization process with the polymer layer 46, and the critical dimension of the contact holes can be lowered by the thickness of the polymer 46. Referring to FIG. 4E', the photoresist pattern 45 covered with the polymer layer 46 is used as a etch mask to insulate the insulating interlayer 44 to form contact holes having critical dimensions and exposing the bit line contact plugs 42. 47. Subsequently, the photoresist pattern 45 and the polymer layer 46 are removed. Referring to FIG. 4F, a bit line 48 that contacts the bit line contact plug 42 through the contact hole 47 is formed. In a preferred embodiment of the invention, bit line 48 is formed by w, T i or C 〇 . Figure 5 shows the fluidization temperature dependence of the critical dimension K&K. In Figure $, κ represents the critical dimension of the photoresist pattern formed by exposure of a light source having a wavelength in the range of 157 nm to 193 nm (such as an ArF laser or F2 laser) according to a conventional method, and Kf represents The critical dimension of the photoresist pattern formed by the present invention. That is, the 'critical dimension K' is obtained from the photoresist pattern on which the polymer layer is formed after the fluidization process. As shown in Figure 5, the critical dimension can be reduced by 20 angstroms. By the third embodiment of the present invention, in order to form a fine pattern and improve reliability, a photoresist pattern formed by exposure of a light source having a wavelength ranging from 157 nm to 193 nm after fluidizing the photoresist pattern can be formed. A polymer layer is formed thereon. Therefore, by forming a polymer layer on the photoresist pattern and simultaneously etching the partially insulating interlayer with a plasma generated by fluorine and oxygen, it is possible to prevent the photoresist from being used in the etching process using the photoresist pattern as a mask. The pattern is deformed. Also after the formation of the polymer layer on the resisting agent pattern of the fluidization process, the -14- paper scale is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm). 1299884 A7 ______B7_ ____ V. Description of invention (12) The photoresist pattern is deformed by the photoresist pattern as an etching mask to define a fine area. Further, the critical dimension can be lowered by the thickness of the polymer layer, and therefore, a fine pattern can be obtained. Further, the etching resistance of the photoresist pattern can be improved by hardening the photoresist pattern by injecting with Ar or electron beam.隹 : : : : : : : : : : : : : : : : : 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 -15-

Claims (1)

Ι2998|1· 7 Patent Application Chinese Patent Application Range Replacement Page (July 1992) Patent Application No. 1 · An etching method using a photoresist pattern as an etching mask, which comprises the steps of: forming the photoresist layer by using a light source having a wavelength ranging from 157 nm to 193 nm After exposure, the photoresist layer is developed to coat the photoresist pattern; a polymer layer is formed, and a portion of the dry etching layer is etched simultaneously with a mixture of a fluorine-based gas, an Ar gas, and a helium gas. Wherein the fluorine-based gas is CxFy or CaHbFe, and wherein the X, y, a, b and c are respectively in the range of 1 to 1 ;; and the polymer layer and the photoresist pattern are used as an etching hood The curtain etches the I& etch layer. 2. The method of claim 1, wherein the light source is an ArF laser or an F2 laser. 3. The method of claim 2, wherein the photoresist layer is formed from a COMA (cycloolefin-maleic anhydride) family or an acrylate group. 4. The method of claim 1, wherein the polymer layer is provided by providing about 5 seem to about 20 seem fluorine-based gas, about 1 〇〇seem to about 1000 sccm of Ar gas, and about 1 Seem to about 5 seem gas 2 gas formation. 5. The method of claim 4, wherein the polymer layer is at a pressure of from about 500 watts to about 2000 watts at a pressure of from about 1 Torr to about 5 Torr and from about 25 ° C to about 80. . (The temperature is formed from about 10 seconds to 60 seconds. 6. According to the method of claim 1 of the patent application, it is further formed in the optical scale. \78\78817-920725 .doc/mg · 1 y paper scale Applicable to China National Standard (CNs) A4 specification (210 X 297 mm)~ ' --- Gutter 1299884 The resist pattern then includes a step of hardening the photoresist pattern. 7. The method of claim 6, wherein the ion is injected into the photoresist pattern in a step of hardening the photoresist pattern. 8. The method of claim 7, wherein the Ar ion is at an energy of from 1 〇〇 电子 to 3 〇〇 3 volts to about 10 / / 3 3 Dosage injection. 9. The method of claim 6, wherein the photoresist pattern is treated with Ar plasma in the step of hardening the photoresist pattern. The method of claim 9, wherein the step of hardening the photoresist pattern is from about 1 mA to about 10 mTorr at a power of from about 500 watts to about 2 watts. The pressure is carried out. 11. The method of claim 6, wherein the electron beam is injected into the photoresist pattern in a step of hardening the photoresist pattern. 12. The method of claim 3, wherein the electron beam is injected at an energy of from about 400 microcoulombs/cm3 to about 4000 microcoulombs/cm3. 13. The method of claim 1, further comprising the step of hardening the photoresist pattern after forming the polymer layer. 14. The method of claim 13, wherein the Ar_ sub-system is implanted into the photoresist pattern by a step of hardening the photoresist pattern. 15. The method according to claim 14, wherein the Ar ion is implanted at a dose of from about 100 angstroms to about 300 angstroms per volt by an energy of from about 1 〇1 G/cm 3 to about 1 〇 15 /cm 3 . . 16. The method of claim 13, wherein the photoresist pattern is treated with Ar plasma in the step of hardening the photoresist pattern. -2 - O:\78\78817-920725.doc/mg This paper scale is applicable to China National Standard (CNS) A4 specification (210X297 mm) 1299884 A8 B8 C8 D8 VI. Patent application scope 17. According to the patent application scope 16 The method of claim 7, wherein the step of hardening the photoresist pattern is carried out at a pressure of from about 500 watts to about 2000 watts at a pressure of from about 1 milliTorr to about 10 milliTorr. 18. The method of claim 13, wherein the electron beam is injected at an energy of from about 400 microcoulombs/cm3 to about 4000 microcoulombs/cm3. 19. The method of claim 1, further comprising the step of fluidizing the photoresist pattern after the step of forming the photoresist pattern. According to the method of claim 19, wherein The step of fluidizing the photoresist pattern is carried out by hot plate, oven or UV baking at a normal pressure of from about 100 ° C to about 220 ° C for from 1 minute to 30 minutes. Order -3- O:\78\78817-920725.doc/mg This paper size applies to the Chinese National Standard (CNS) A4 specification (210X297 mm)