TW594424B - Method of improving depth of focus (DOF) in advanced photolithography process - Google Patents

Abstract

A method for improving the depth of focus in a photolithography process so as to provide improved optical resolution is provided. It includes the steps of: (a) forming a photoresist layer on a semiconductor wafer, the photoresist layer contains a polymer resin which is selected such that it will react with a reactive chemical to form a thin SiOx or TiOx layer after it has been exposed to UV light, wherein x ranges from 1 and 2 and the reactive chemical can be hexamethyldisilazane or titanium, ethoxide (Ti(OC2H5)4), (b) subjecting the photoresist layer to a deep UV irradiation under a photomask, (c) using a developer solution portions of the photoresist that have been exposed to the deep UV irradiation, (d) subjecting the remaining photoresist layer to a flooding UV radiation, and (e) subjecting the remaining photoresist layer to the gaseous reactive chemical so that at least an outermost portion of the polymer resin is converted to a SiOx or TiOx containing polymer resin with enhanced chemical resistance.

Description

944944

This case is about a method of increasing the depth of focus during the lithography process and then improving the optical resolution. More specifically, this case relates to a method for reducing the thickness of the photoresist layer. In the semiconductor device manufacturing process, the optical resolution of the photoresist layer is improved by increasing the focus / clothing degree, and the mechanical mechanism of the photoresist layer is retained. And chemical strength to maintain high accumulation of photoresist patterns on the wafer. Improve the optical resolution in the lithography process, while reducing the size of the semiconductor element, and increasing the circuit density. The method provided in this case does not require a large amount of > remanufacturing the appliance but can obtain very effective improvements. In the lithography process, the optical resolution is an important factor that determines the deposition step: it also controls the shrinkage of the semiconductor device. The two-focus depth (DOF) is a king of the depth interval. The $ method, in which all points have the same focal length, is used for the size of the optical resolution in the distance. There are many ways to increase the poly-Vg: such as using a displacement mask, anamorphic lighting, or using an anti-reflective film. Due to the degree, but the meeting room may improve the resistance of this small photoresist layer and the resistance to the hard baked and purple resist layers. The use of the above photoresistive layer and thickness solidity affect the depth of focus. It is unavoidable to do as much as possible. Some of the previous techniques or ion implantation have the mechanical strength of external light irradiation, but there is no method to increase the depth of focus. A larger aperture is acceptable. As a result, the thickness of the photoresist out of focus should be appropriately reduced and the photoresist layer technology should be reduced. Attempts have been made to develop methods to increase the intensity of photoresist release. However, these methods improve their chemical resistance and get a smaller phenomenon than the surface of the layer. However, the method of polymerizing the mechanical layer is only changed. Therefore, the machine is either 0 or 0. Photoresist

: M424 —— V. Description of the invention (2) The thickness of the layer becomes a U.S. patent structure, which is characterized by a certain resolution, the photoresist layer deposited by the polymer or phenolic hydroxy polymer first and a photoresist layer containing a plurality of Amine-rich oxygen plasma • U.S. patented composition, this polyamine is a heavy element of the second oxygen oxygen bond, has a repeating unit of Shi Xi, or is composed of nano. The sensing photoresist.

f Small bottleneck of semiconductor component size. Mu. 5, 26, 2, 283 reveals a high resolution due to the obvious edges and special forces and conditions. The photoresist layer contains an ultraviolet light region which is used to surround an activity: = polymerization of a group of compounds. The first compound contains the imino-imide basin and reacts to generate a strong acid during the light irradiation process. Define the pattern again. After light exposure, the seed is water-based, or water-alcohol, as the base, in which the solution of the siloxane group in which the group or hydroxyl group is dissolved first reacts, and is engraved in the middle. Case 5, 340, 684 discloses a photosensitizer containing a polyamine, consisting of a repeating unit having a hydroxyl group and a unit having a unit, or a repeating unit having a repeating monooxane bond having a hydroxyl group. First, it is not composed of the two components mentioned above and a photosensitizer. The photosensitizer is composed of an ester group of quindiazide sulfonic acid or an amine-ester of quindiazide sulfonic acid. The light component is used as a passive film for semiconductor devices or

U.S. Patent No. 5,3 8 7,4 9 4 discloses a water-containing photoimaging composition. As a photoresist, it contains a rubber-bound polymer containing sufficient carbonic acid functional groups, which can be developed in an alkaline solution. , A photopolymerizable monomer moiety, a photoinitiator, and a polysiloxane compound. U.S. Patent No. 5,711,987 discloses a multi-layer tamper proof electronic coat i nS ’wherein the first layer is a protective layer, which is composed of an over-magnetized silicon-containing material and

Page 7 594424 594424 η Revision MM ^ 88100041 V. Description of the invention (3) One less filler composition. The second layer is a layer of colloidal inorganic siloxane rubber. The composition may be varnish, or any one of silicone polyamidophenols: ¥, amidophenol polymerization US patent 4,200 668, a method of exposing a hole, is attached to the pin of the mask surface defect mask (such as Shi Xi oxygen Hyun), and then promote the "C into the film delamination (such as ... photoresist layer ), To remove the pins with a laser burner, and deposit a solvent-soluble layer on top of the pins, you can put (―) on the part of the pin: part of the photomask layer. After lapping, 1 ;: window layer The solvent on the Haixian mask dissolves the previous techniques mentioned above. However, because of the siloxane and the gulu = alkane incorporated into the photoresist layer, you need to use a strong developer when burning oxygen. T activation, making the junction method, which is to strengthen the photoresist layer with thinning depth of focus during the lithography process can still tolerate the etching intensity, so that the thickness does not affect its quality, improve the potential range == Implanted in the harsh conditions, and the semiconductor components. Also, the resolution is pre-determined to produce a high accumulation. The main improvement of the present invention-: and Hexamethylethionite ammonia sintering (_trans: layer can be layered after exposed to ultraviolet light. Preferably, the photoresist layer is covered; the photoresistive domain of the ^ 10x layer is a polymer with side chains .The photoresist = ethylene is the main trunk of 'tert-butoxy, so the photoresist layer is suitable for g; it is placed in ultraviolet light after development. The case is-"Li Shi :; general development methods. Include: Heart + The method of μ depth, its steps. Page 8 594424 Λ 88100041 V. Description of the invention (4) (1) Coating on a semiconductor wafer-outer total photoresist layer package, resin and photoresistance: (2) : 'Where the generator); (2) Put the zinc photoresist layer on _ first! Should; First, under the hood, perform a deep ultraviolet light reflection (3) The deep ultraviolet ray · · (WHxpq can e BaketP, Ei; photoresist layer, baked after irradiation (:) = developer removed and exposed to the remaining part of the deep purple layer and placed in the irradiated light ~,, U ^ Pass Lv Hai through the pan purple evening umbrella ^, Post-baking (ρΕΒ); and ..., the remaining part of the photoresist layer is illuminated by light !, 'f ::: t part is treated with hexamethylethilazine gas to make the compound tree; Where χ is between j and 2 · Heart steps can be expressed by the following chemical formulas: · ♦ a 'κ 馨 + 叫 ， + —— ^ CHa-CH ^-hotoacid generator —--- > Fiber Generator (Deep UV) + H + by product \\ / ZU 伍 唆 0 〇 = C-0-c— expose (〇) + photoacid generator 0

I I 0 = C-0-C- + CH2-CH +

Bake (PEB) Δ + by product

OH W4424 Case No. 88100041 、 Instructions for CH2 -CH +

Develop

Dissolve

The OH oxygen barrier 1 ^ = Γ is then irradiated in deep ultraviolet light, so that the tertite soil rebels react to hydroxyphenyl groups, and then bake and then react with ODS to form the Si0x layer. As shown in the following formula. This forms the si (^ layer

The rem.丨 ning photoresist The change of + CH2rCH + + CH2_CH + greatly increases the chemical inactivation of the photoresist layer during subsequent etching and ion implantation reactions.

Expose + photoacid generator- hv

UV + Hf + by product 0 i I 〇 = C-0 ~ C— + ch2-ch + 0

Bake_) Δ 0 I 0 = C-0

o = c-o-c- · + ch2, + (〇) + by product OH 1- -f-CHa -f-CH2 ~ CH-)-

* HMDS

Silylate 0

OH -Si.

Page 10 rm424 Month Revision 88100041 V. Explanation of the invention (6) Going deeper. Solution: This case can be obtained by the following diagram and detailed description. The photoresist layer invented by a deep UV light under a photomask is developed. Illustration. The second figure. The remaining part of the photoresist layer is exemplified by the ultraviolet light irradiation. The fourth figure. The remaining part of the photoresist layer is used to make the photoresist layer β A 1 to be prepared. Ammonia gas layer. The outer layer part is reacted to form a SiOx-containing polymerization icon. The main drawing numbers are as follows: The outermost part of the photoresist layer of the semiconductor wafer photoresist layer. The present invention discloses a method of intensity of Θ to make it more compact. Improve the mechanical and chemical harsh conditions of the photoresist layer. The present invention can withstand the increase in the thickness of the resist layer when the thickness of the resist layer is reduced by the engraving or ion implantation. During the manufacturing process of the semiconductor device, the semiconductor device with small light is used. The depth of focus is known to make the size larger. The present invention provides a > 2 / M method. The light used in the present invention: after the square light with improved properties of the remaining photoresist layer. It is a polymer with hexamethylethionamine, which is exposed to a thin SiOx layer with ultraviolet radiation, and the gas = (丄) gas The reaction to form a chemically inactive polyphenylene polylayer is a kind of polybutoxy-containing lining. Generally, the photoresist layer contains a photoactive 594424

Case No. 88100041 V. Description of the invention (7) Depleted compounds, which react to form a strong acid in the process of light irradiation. Suitable for use in the present invention, the activating substance is often used in many prior arts, and is not repeated here. In the present case, in the presence of an acidic substance formed by the reaction, tert-butoxyl is a phenyl group and is easily soluble in a test solution. During the development, the remaining mask of t-butoxycarbonyl group remained, and the light was irradiated. This will make the above reaction proceed. The rule: the group will react with the hexamethylethisilazine (hmds) gas. Invert a S1 Ox layer. Otome is shown in the photo cover of Figure 1. Oxygen-based polyphenylene. The exposed photoresist layer is baked and chemically treated. Cowpea can be wθ I, .. Gongzhizhi, Guangjun in Fengdao. ΓΡΠ μ was developed by hydrolysis. The photoresist layer 2 is formed on + V bile yen 1, this step can be expressed by the following reaction: + ch2 "ch + + CH2 called Expose 0 + photoacid generator > —— > Photoacid generator (DeeP uv) + Hf * rby product mo = c-0-0- case, ΐ; step :: =: Table: photoresist layer " 影 _ 现 其 圊 + CH2 -CH + *

Developer > Dissolve

Develop OH

Page 12 594424

(12) After the resist layer is developed, a one-time reinforcement reaction is performed. Please refer to the second picture (below) for the remaining photoresist layer. See also Λ 8888. Regulation 5. Description of the invention (8). This step The chemical reaction is as follows. 70 + hungry, called + ch2-ch +

Expose ψ + photoacid generatorhv

UV o = coc— f〇l rH ^ -foy product 0 II o = c—o ~ * c— As shown in the fourth figure, the pan-ultraviolet light is irradiated and the light is baked: the photoresist layer and six The methyl ethyl ammonium ammonia burning gas reaction makes the outermost part 4 react to the bottom of the layer to form a polymer resin containing SiOx. The chemical reaction of this step is as follows.

HMDS + ch2 「ch + + ch2-ch + #

Silylate

OH 0

The silicon atom in the I-Sl · Shishu reaction will be bonded to the other three silicon oxygen bonds. Under the conditions of §, X in the Si 0x layer is about 2, which means that an oxygen atom is connected to each of the Shi Xi atomic bonds. '、 Suzuki transformed the t-butoxycarbonyl group into the S i χχ layer to improve the chemical inactivation of the photoresist layer required for the ion ionization reaction under twisting. Therefore, increasing the thickness of the photoresist layer when the thickness of the photoresist layer is reduced. The focus of the film manufacturing process can be added to its circuit accumulation, thereby reducing the size of semiconductor components. 5 ^ also increased

The preferred embodiment described has fully explained the sixth aspect of the present invention * " " " " " 1----------------------- ------------------------------------ Head 〇 ΙΊ. · ^ Ι1 tnu < r < .r <p; * u ». * ··« ji.v.it.ws mm ....... — — — — — — — 594424 _ Case No. 88100041 _ year month day __ 5. Description of the invention (9) There are many ways to improve this technique. This case may be modified in various ways by those skilled in the art, but none of them can be protected as attached to the scope of patent application.

594424 _Case No. 88100041_ Year Month Revision _ ^ Brief Description of the Drawings First Picture: The schematic diagram of the photoresist layer of the present invention placed under a photomask for deep ultraviolet light irradiation. FIG. 2 is a schematic diagram of developing a photoresist layer according to the present invention. Figure 3: Schematic diagram of the remaining part of the photoresist layer being irradiated with pan-ultraviolet light. Figure 4: The remaining part of the photoresist layer is exposed to hexafluorethynylsilazane gas, and the outermost part of the photoresist layer is reacted to form a polymer layer containing Si Ox.

Page 15

Claims (1)

^^ 4424 Amended six '^ —— Its chemical formula is as follows: polystyrene with fluorenyl butoxycarbonyl' group side bond fCH9—CH > -I '' Θ 6 6 If from, 〇 = coc ~ Poly ϊ of the chain ί The "aromatic method" described in item 5 wherein the t-butoxycarbonyl side has a chemical formula such as = polymer resin reacts to polystyrene containing hydroxyphenyl group, and the pan-ultraviolet light in I · fine 2-strict OH Irradiation can be used: the method described in the first item of the application range, and δ is used to make: the remaining J resist layer exposed. The method of 11 is the method described in the method of ββLK of the resin β. The S i ox-containing polymer is shown in the formula as follows: fCH, one CH + two I 〇-Si-9: silicon atom through oxygen Bonded and connected with other silicon atoms. • A method to improve the chemistry of the photoresist layer and / 戍 # ^ steps include: a method for the corrosion resistance of a private girl, the steps to modify the month --- plug No. 88100. 4 ~ | 6. The scope of patent application is for a compound resin on a semiconductor wafer and a photoresist-photoresist layer. The photoresist layer contains a UV (light forward) = =, the polymer resin is exposed to It reacts with ultraviolet light to form a thin post-bake, and then reacts with hexamethylethilazine gas; put 4 photoresist layer under a photomask, and irradiate with a deep ultraviolet light to pass the deep ultraviolet light to 0; 7 (1) Use a dark photoresist layer to illuminate the photoresist layer and bake the light; h. Remove the part of the photoresist layer that is exposed to deep ultraviolet light; Glare ^ The remaining part of the photoresist layer is exposed to flood ultraviolet light Post-baking; 1: Γ and the remaining part of the photoresist layer that has been exposed to ultraviolet light, and the remaining part of the photoresist layer is illuminated with hexamethylethylsilazane gas. S ^ r ^ ti ^ ^ ^ ^ ^ ^ m ^ ^ ^ Si0x ^ ^ ^ and the X is between 1 and 2. The polymer resin is a polystyrene containing a polymer having a tert-butoxycarbonyl side chain as described in item 9 of the scope of application. The method described in item 9 of the application scope has polybutoxycarbonyl side chain polystyrene. After external light, the terbutoxycarbonyl group reacts to form a hydroxybenzyl group. 12. The method according to item 11 of the scope of application, wherein the hydroxybenzyl group is converted into a -Si0x layer after being treated with hexamethylethione gas. · Gas 1 3. The method according to item 9 of the scope of application, wherein the polymer resin is polystyrene containing a tert-butoxycarbonyl side chain, and its chemical formula is as follows: ^ ^ Page 18 594424 _Case No. 88100041_ Year and Month Amendment _ 6. Scope of patent application I ό · o = c ~ o ~ c—! 14. The method described in the scope of application No. 13 where the special butoxygen Polystyrene polymer resin with carbonyl side chains reacts to polystyrene containing hydroxyphenyl circles, and its chemical formula is as follows: OH '· · · · · · *. 1 5 · The method as described in item 9 of the scope of application, wherein the flooding of ultraviolet light affects only the outermost part of the remaining photoresist layer. 16 · The method as described in item 9 of the scope of application, wherein the polymer resin containing Si Ox is represented by a chemical formula as follows: § · One Si-where silicon atoms are bonded to other silicon atoms by oxygen bonding. 苐 Page 19