TWM513371U - Structure of extending optical mask lifetime - Google Patents

Description

Structure for extending the life of the reticle

The present invention relates to a structure for extending the life of a reticle, and more particularly to a composition for absorbing organic pollutants and inorganic pollutants such as ammonia and sulphur oxides, and the use of the composition on a reticle.

According to the current semiconductor device manufacturing technology, the circuit pattern of the semiconductor device is to transfer the circuit pattern to the surface of the germanium wafer through a lithography process, specifically, using a light source of a specific wavelength to project through a photomask. In a way, the circuit pattern is transferred to the surface of the germanium wafer. In order to achieve the number of semiconductor elements, such as transistors, multiplied by the unit area, the line width of the semiconductor circuit is reduced as its main technical solution. At present, deep ultraviolet light (DUV) with a wavelength of 193 nm is used as an exposure light source for the lithography process. It can make the minimum line width of the semiconductor circuit reach 7~10 nanometer (nm).

Due to the miniaturization of semiconductor components, defects in the mask may cause distortion or deformation of the circuit pattern on the surface of the wafer during the manufacturing process of the semiconductor device, even if only defects having a nanometer size such as 20 nm to 200 nm may cause a semiconductor circuit pattern. damage. One of the reasons known to cause reticle defects is that the surface of the reticle is contaminated by contamination particles; in order to maintain the quality of the reticle during use, a conventional method is to provide a reticle protection on the surface of the reticle. A pellicle is used to prevent contaminants from falling on the surface of the reticle to form contaminating particles.

However, even with the above-mentioned reticle protective film, it is practically impossible to completely avoid the pollution caused by the pollutant on the surface of the reticle. The source or cause of the pollutant of the reticle includes the pollutants generated from the environment and the cavity, The foregoing environment includes a clean room, a storage environment for the reticle, and equipment and chemicals in the lithography process; these chemicals or contaminants may still pass through the vent or film of the reticle protective film. And into the inner cavity of the reticle. On the other hand, the adhesive contained in the adhesive for adhering the reticle protective film to the surface of the reticle and the frame adhesive of the reticle itself may also be outgassing or other in the lithography process. Causes of the formation of pollutants, generally organic pollutants, inorganic pollutants such as ammonia and sulphur oxides or other pollutants will deposit or adhere to the surface of the reticle to form a mist ( Haze), when a pollutant (such as ammonium sulfate) accumulates to a certain extent, it will form a large crystal or particle, and then focus and transfer with the circuit pattern of the reticle in the lithography process. As for the surface of the wafer, distortion or distortion of the circuit pattern is caused. Therefore, how to absorb pollutants more effectively during the use of the mask to prevent the generation of mist has become one of the problems that the industry is trying to solve.

In one aspect, the present invention provides a structure for extending the life of the reticle, comprising: 0 to 50 weight percent (wt%) adsorbent; 50 to 80 wt% Dimethyl polypropoxy methylammonium chloride ); and 0~50wt% acrylic glue.

In some embodiments, the adsorbent is boric acid or sodium sulfite.

In some embodiments, the adsorbent is 20-50% by weight, the dimethylpolypropyloxymethylammonium chloride is 45-80 wt%, and the acrylic adhesive is 0-10 wt%. . In a preferred embodiment, the acrylic gum is present in an amount of 1% by weight, more preferably 0.9% by weight, 0.8% by weight, 0.7% by weight, 0.6% by weight, 0.5% by weight, 0.4% by weight, or 0.3% by weight. 0.2wt%, 0.1wt%, or 0wt% (meaning that acrylic glue can be dispensed).

In some embodiments, the adsorbent is present in an amount of from 0 to 15% by weight, the dimethylpolypropoxymethylammonium chloride is present in an amount of from 25 to 75 wt%, and the acrylic gum is present in an amount of from 25 to 75 wt%. . In a preferred embodiment, the adsorbent is present in an amount of 1% by weight, more preferably 0.9% by weight, 0.8% by weight, 0.7% by weight, 0.6% by weight, 0.5% by weight, 0.4% by weight, 0.3% by weight, or 0.2%. Wt%, 0.1wt%, or 0wt% (meaning that acrylic glue can be used).

In another aspect, the present invention provides a method of extending the life of a reticle, comprising the steps of: providing a reticle having a surface having a reticle protective film assembly bonded thereto, the reticle protective film assembly The utility model is composed of a frame and a transparent film combined on the top surface of the frame, so that the transparent film will close the top surface of the frame, so that the frame has an inner cavity wall surface, and the reticle protection component and the reticle are combined to form an inner cavity; Applying a first composition containing 20-50% by weight of adsorbent, 45-80% by weight of dimethylpolypropyloxymethylammonium chloride and 0-10% by weight of acrylic adhesive to the reticle protective film module a wall surface; and a second composition comprising 0 to 15 wt% of adsorbent, 25 to 75 wt% of dimethylpolypropoxymethylammonium chloride, and 25 to 75 wt% of acrylic adhesive applied to the mask protection The bottom surface of the frame of the membrane module can be used as an adhesive for bonding to the reticle.

In some embodiments, the method further comprises the steps of: containing 20 to 50 wt% of adsorbent, 45 to 80 wt% of dimethylpolypropoxymethylammonium chloride, and 0 to 10 wt% of acrylic rubber. The first composition is applied to the top surface of the frame of the reticle protective film assembly, and can be used as an adhesive for bonding the frame to the transparent film.

In another aspect, the present invention provides a structure for extending the life of a photomask, comprising: a photomask having a surface; and a photomask protective film assembly comprising a frame and a transparent film attached to the top surface of the frame. The top surface of the frame is closed by a transparent film, so that the photomask protective film assembly has a cavity wall surface; the photomask protective film assembly is bonded to the surface of the photomask, and the photomask protective film assembly and the photomask form an inner cavity; a first composition of 20 to 50 wt% of adsorbent, 45 to 80 wt% of dimethylpolypropoxymethylammonium chloride, and 0 to 10 wt% of acrylic rubber is applied to the inner cavity of the photomask protective film assembly a second composition comprising 0 to 15 wt% of adsorbent, 25 to 75 wt% of dimethylpolypropoxymethylammonium chloride, and 25 to 75 wt% of acrylic adhesive applied to the mask protection The bottom surface of the frame of the membrane module serves as an adhesive for bonding to the reticle.

In some embodiments, the first composition comprising 20 to 50 wt% of adsorbent, 45 to 80 wt% of dimethylpolypropoxymethylammonium chloride, and 0 to 10 wt% of acrylic gum is further coated. The top surface of the frame of the reticle protective film assembly can be used as an adhesive for bonding to a transparent film.

The following description of the drawings is a preferred embodiment for the purpose, embodiments, technical features and functions of the present invention, and is not intended to limit the present invention.

(A1) ‧ ‧ exposure area

(A2) ‧ ‧ non-exposed areas

(10) ‧‧‧Photomask

(11) ‧ ‧ surface

(2) ‧‧‧Photomask protective film assembly

(21)‧‧‧Transparent film

(22) ‧‧‧Framework

(221)‧‧‧ Sidewall

(222) ‧ ‧ vents

(223) ‧‧‧Filter membrane

(23) ‧‧‧Frame Adhesive

(24) ‧‧‧film adhesive

(25) ‧‧‧ lumen

(26) ‧‧‧Adhesive layer in the frame

1A~F are the results of a Fourier-Transform Infrared Spectrometer (FT-IR) analysis of the composition of the present invention; the sample of FIG. 1A is a carrier of dimethylpolypropoxymethylammonium chloride (sample 1) The sample of Figure 1B is a carrier of dimethylpolypropyloxymethylammonium chloride treated with ammonia (sample 2); the sample of Figure 1C is containing 50 wt% of carrier dimethylpolypropoxymethylammonium chloride and 50 wt Composition of % boric acid (Sample 3); the sample of Figure 1D is a composition containing 50 wt% of carrier dimethylpolypropyloxymethylammonium chloride and 50 wt% of boric acid treated with ammonia gas (sample 4); sample of Figure 1E The composition containing 50% by weight of carrier dimethylpolypropyloxymethylammonium chloride and 50% by weight of boric acid was treated with ammonia gas and then treated with sulfur oxides (SOx) (sample 5); the sample of FIG. 1F was 50% by weight. The composition of the carrier dimethylpolypropyloxymethylammonium chloride and 50% by weight of boric acid was treated with ammonia gas and then treated with sulfur oxides (SOx) and then treated with ammonia gas (sample 6).

2 is a plan view showing the configuration of an embodiment of the reticle when the composition is applied to a reticle.

Figure 3 is a cross-sectional view showing the structure of the reticle of Figure 2 at the position III-III.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined.

As used herein, the singular forms "", "," Thus, for example, reference to "the same" includes a plurality of such references and equivalents as known to those skilled in the art.

As used herein, the term "contaminant" means a contaminant that will deposit or adhere to the surface of the reticle to gradually form a mist that will form larger crystals or particles when the contaminant accumulates to some extent. Contaminants include, but are not limited to, organic pollutants and inorganic pollutants. The organic pollutants include, but are not limited to, β-chloroethyl acetate, 1,3-dioxane, toluene, N-dimethylaminomethyl N-dimethylamino methyl-tert-butyl-isopropyl phosphine, 1-propoxy 2-propanol, triethylsilane, 1,2 - 1,2-propanediol, 2-acetate, S-(3-hydroxypropyl)thioacetate, 1-methyl-4- (1-methyl-4-(1-methylethenyl)-cyclohexene), 1-butanol, benzene, 1-chloro-2-(trifluoromethyl) -(benzene,1-chloro-2-(trifluoromethyl)-), 2-propanone, 1-propanone, 1-(acetyloxy), p-xylene , methyl 2-butoxy acetate, 3-heptanone, styrene, bicyclo[3.1.0]hex-2-ene, 2-methyl -5-(1-methylethyl)-(bicyclo[3.1.0]hex-2-ene,2-methyl-5-(1-methylethyl)-), L-homoserine, o-propyl ( L-homoserine, o-propyl), benzene, 1-ethyl-2-methyl-benzene, benzene, 1,2,4-trimethyl (benzene, 1,2,4-trimethyl), benzene, 1,4-diethyl (benzene, 1,4-diethyl-). The inorganic pollutants include, but are not limited to, ammonia (NH ₃ ) and sulfur oxides (SO _x ) such as sulfur monoxide (SO), sulfur dioxide (SO ₂ ), sulfur trioxide (SO ₃ ), and disulfide ( S ₂ O), sulfur monoxide dimer (S ₂ O ₂ ).

As used herein, the term "carrier" means a compound that can be combined with an adsorbent such that the adsorbent can be applied to a surface with a carrier. Preferably, the carrier also adsorbs organic contaminants. The carrier is an ionic liquid including, but not limited to, Diethyl polypropoxy methylammonium chloride.

As used herein, the term "adsorbent" means a mineral acid that combines with an ionic liquid to form a hydroxyl group (-OH) at the end, and which adsorbs inorganic contaminants such as ammonia (NH ₃ ) and sulfur oxides (SO). _x ). The adsorbent includes, but is not limited to, boric acid and sulfurous acid.

The present invention will now be described in more detail with reference to the following examples, which are intended to be illustrative and not limiting.

Example 1 Analysis of the ability of the composition of the present invention to absorb inorganic pollutants

In the present embodiment, the Fourier-Transformed Infrared Spectrometer (FT-IR) was used to measure the ability of the composition of the present invention to absorb inorganic contaminants. Carrier dimethylpolypropoxymethylammonium chloride (sample 1), carrier dimethylpolypropyloxymethylammonium chloride treated with ammonia (sample 2), the present composition (containing 50% by weight of carrier dimethyl Polypropoxymethylammonium chloride with 50% by weight of boric acid) (Sample 3), and the inventive composition (containing 50% by weight of carrier dimethylpolypropyloxymethylammonium chloride and 50% by weight of boric acid) treated with ammonia gas ( Each sample of sample 4) was separately measured in a Fourier transform far infrared spectrometer. The results are shown in Figures 1A, 1B, 1C, and 1D, respectively.

As shown in Figures 1A and 1B, the carrier dimethylpolypropoxymethylammonium chloride is in the absence of ammonia treatment (sample 1) and in the case of ammonia treatment (sample 2). The wave number is about 3400cm ^-1 to 3500cm ^-1 . There is an absorption wave front (as indicated by the arrow, the light transmittance is shown in Figure 1A to Figure 1F, and the lower the light transmittance, the higher the absorption rate). The carrier, dimethylpolypropyloxymethylammonium chloride, does not absorb ammonia.

Further, as shown in FIG. 1C, the present composition (containing 50% by weight of carrier dimethylpolypropyloxymethylammonium chloride and 50% by weight of boric acid) in the absence of ammonia treatment (sample 3), also in wave number at about 3400cm ^-1 to 3500cm ^-1 absorption of a wave front (as shown at arrow), showing the creation of the present composition has not been adsorbed harmful substances.

As shown in FIG. 1D, after the present composition (containing 50% by weight of carrier dimethylpolypropyloxymethylammonium chloride and 50% by weight of boric acid) was treated with ammonia gas (sample 4), the wave number was about 3400 cm ^{-1 .} At 3500 cm ^-1 there is a second absorption wave front (as indicated by the arrow), which shows that the composition of the present invention adsorbs ammonia gas, and the following chemical reaction is carried out: The two absorption peaks shown in Figure 1D (as indicated by the arrows) indicate that the composition of the present composition has two nitrogen-hydrogen bonds (-NH) at the end.

The above sample 4 was then treated with sulfur oxides (SO _x ) (sample 5) and placed in a Fourier transform far infrared spectrometer. The results shown in Figure 1E, originally at about 3400 cm ^-1 to the wave number of 3500cm ^-1 of absorption at two wave front (FIG. 1D) had disappeared, and the absorption wave front having a wave number of 3500cm ^-1 of at about (As indicated by the arrow in Fig. 1E), it is shown that the composition of the present invention further adsorbs oxysulfide, and the following chemical reaction is carried out: One of the absorption peaks shown in Figure 1E (as indicated by the arrows) indicates that the composition of the present composition has a nitrogen-hydrogen bond (-NH) at the end.

The sample 5 described above was then treated with ammonia gas (sample 6) and placed in a Fourier transform far infrared spectrometer. The results shown in FIG. 1F, at about 3400cm 3500cm ^-1 at a wave number of ¹ to appeared two absorption wave front (as shown at arrow), shows the creation of a composition further adsorbed ammonia gas, The following chemical reactions were carried out: Wherein the two absorption peaks shown in Figure 1F (as indicated by the arrows) indicate that the end of the composition has two nitrogen-hydrogen bonds (-NH) from -SO _x -NH ₂ , and the original The nitrogen-hydrogen bonding portion of [carrier-adsorbent-NH] has an absorption peak overlap because its chemical property is the same as one of the nitrogen-hydrogen bonds from -SO _x -NH ₂ .

It can be seen from the present examples that the composition provided by the present invention can absorb inorganic pollutants in the environment, particularly ammonia gas and sulfur oxides.

Example 2 Analysis of the ability of the composition of the present invention to absorb organic pollutants

In the present example, the ability of the composition of the present invention to absorb organic pollutants was measured using a Gas Chromatography-Mass Spectrophotometer (GC-MS). The present invention, dimethylpolypropoxymethylammonium chloride (sample A), which has not absorbed organic volatile gas, and dimethylpolypropoxymethylammonium chloride (sample B), which has absorbed organic volatile gases They were placed on an aluminum pan and heated at 90 °C for 2 hours. The content of organic volatile gases was analyzed by gas chromatography mass spectrometry using helium as a carrier gas. The integrated area of Total Ions Chromatography (TIC) was used. Represents the content of organic volatile gases. The results show that the relative amount of organic volatile gas released by the inventive carrier dimethylpolypropoxymethylammonium chloride (sample A) which does not absorb organic volatile gas is 3.4 x 10 ⁷ /g, and the organic volatile gas has been absorbed. The carrier, dimethylpolypropoxymethylammonium chloride (sample B), upon heating, releases organic volatile gases, which release a relative amount of organic volatile gas of 8 x 10 ⁹ /g. It can be seen that the carrier of the present invention, dimethylpolypropoxymethylammonium chloride, can absorb organic volatile gases and reduce the amount of organic volatile gases in the environment of the reticle.

In addition, acrylic glue (organic glue, will release organic pollutants) (sample C) and the original carrier dimethylpolypropoxymethylammonium chloride containing acrylic adhesive (containing 33wt% carrier dimethyl Polypropoxymethylammonium chloride and 67wt% acrylic gel (sample D) were placed on an aluminum pan, heated at 90 °C for 2 hours, and then volatilized by gas chromatography mass spectrometry using helium as a carrier gas. For the analysis of the gas content, the integrated area of the total ion chromatogram (TIC) represents the content of the organic volatile gas. The results showed that the relative amount of organic volatile gas released by acrylic (sample C) was 1.1 x 10 ⁹ /g, while the original carrier containing acryl poly(oxymethyloxymethyl ammonium chloride) (sample D) The relative amount of organic volatile gas released is 1.1 x 10 ⁸ /g. From this, it is understood that the composition containing the inventive carrier dimethylpolypropyloxymethylammonium chloride can reduce the amount of organic volatile gas released by the acrylic adhesive.

Example 3 Application of the composition of the present invention to a photomask

In the present embodiment, the composition of the present invention is applied to a photomask to absorb organic pollutants and inorganic pollutants in the environment. Please refer to FIG. 2 and FIG. 3 together. FIG. 2 and FIG. 3 are respectively a planar structural view of a photomask applied to a semiconductor process and a structural sectional view thereof.

As shown in FIG. 2, in the embodiment, the reticle 10 is applied to a deep ultraviolet (DUV) lithography process, and the reticle 10 has a surface 11 having an exposure area A1 and A non-exposed area A2, wherein the exposed area A1 has a circuit pattern formed on one surface 11 of the reticle 10 in a photomask making process.

As shown in FIG. 2 and FIG. 3, the surface 11 of the reticle 10 is attached with a reticle protective film assembly 2, and the reticle protective film comprises: a transparent film 21, a frame 22, a frame adhesive 23, and a film. Adhesive 24 and an adhesive layer 26 in the frame. The frame adhesive 23 is a formulation of the composition of the present invention containing 33% by weight of carrier dimethylpolypropyloxymethylammonium chloride and 67% by weight of acrylic glue. The film adhesive 24 and the in-frame adhesive layer 26 are also another formulation of the compositions of the present invention comprising 50% by weight of carrier dimethylpolypropyloxymethylammonium chloride and 50% by weight of boric acid. The transparent film 21 of the reticle protective film unit 2 is adhered to the top surface of the frame 22 by the film adhesive 24, and the bottom surface of the frame 22 is attached to the periphery of the surface 11 of the reticle 10 by the frame adhesive 23 to light The exposure area A1 of the cover 10 is shielded, and the transparent film 21 By the support of the frame 22 without contacting the reticle 10, and forming a cavity 25 between the reticle protective film assembly 2 and the reticle 10, one of the side walls 221 of the frame 22 of the reticle protective film assembly 2 has a vent hole. 222 is used to balance the air pressure of the inner cavity 25 and the ambient air pressure. The vent hole 222 is provided with a filtering membrane 223 for preventing intrusion of pollutants or particles into the inner cavity 25. The adhesive layer 26 of the frame is adhered to the inner cavity formed by the frame 22. Wall.

When the composition of the present invention is applied to a reticle by the above method, the frame containing the composition of the present composition (33 wt% of carrier dimethylpolypropyloxymethylammonium chloride and 67 wt% of acrylic glue) is adhered. In addition to providing adhesion, the adhesive 23 also provides a cushioning effect, which can effectively prevent the reticle 10 from being deformed by the pressurization of the reticle protective film assembly 2, and the carrier dimethylpolypropylene oxide The methyl ammonium chloride can effectively reduce the amount of organic volatile gas released by the acrylic glue, and prevent the release of organic harmful substances into the inner cavity 25.

On the other hand, a film adhesive 24 containing another formulation of the present composition (50 wt% of carrier dimethylpolypropyloxymethylammonium chloride and 50 wt% of boric acid) and the in-frame adhesive layer 26 provide adhesion. In addition, the carrier dimethylpolypropyloxymethylammonium chloride can adsorb organic harmful substances in the environment, while the adsorbent boric acid can adsorb inorganic harmful substances in the environment, especially ammonia gas and sulfur oxides.

Therefore, when the composition of the present invention is applied to the reticle by the above method, the deposition of organic pollutants and inorganic pollutants in the luminal cavity environment can be effectively reduced, thereby preventing mist and crystallization on the surface of the reticle. / or particles, and extend the life of the mask.

In addition, the composition of the present composition as the frame adhesive 23, the film adhesive 24, and the in-frame adhesive layer 26 is only one of the preferred embodiments of the present invention, and is not intended to limit the scope of the patent.

The embodiments and/or the embodiments described above are merely illustrative of preferred embodiments and/or implementations of the present invention, and are not intended to limit the implementation of the present invention in any way. A person skilled in the art may make some modifications or modifications to other equivalent embodiments without departing from the spirit and scope of the invention.

(A1) ‧ ‧ exposure area

(A2) ‧ ‧ non-exposed areas

(10) ‧‧‧Photomask

(11) ‧ ‧ surface

(21)‧‧‧Transparent film

(22) ‧‧‧Framework

(23) ‧‧‧Frame Adhesive

(24) ‧‧‧film adhesive

(25) ‧‧‧ lumen

(26) ‧‧‧Adhesive layer in the frame

Claims (2)

A structure for extending the life of a reticle comprises: a reticle having a surface; a reticle protective film assembly comprising a frame and a transparent film attached to the top surface of the frame, the top surface of the frame being closed via a transparent film The reticle protective film assembly has an inner cavity wall surface; the reticle protective film assembly is coupled to the reticle surface to form a cavity for the reticle protective film assembly and the reticle; and a sorbent containing 20 to 50 wt%, a first composition of 45-80 wt% dimethylpolypropoxymethylammonium chloride and 0-10 wt% acrylic adhesive applied to the inner wall surface of the reticle protective film assembly; a second composition of 0 to 15 wt% adsorbent, 25 to 75 wt% dimethylpolypropyloxymethylammonium chloride, and 25 to 75 wt% acrylic adhesive applied to the photomask protective film assembly The bottom surface of the frame serves as an adhesive for bonding to the reticle. The structure for extending the life of the reticle as described in claim 1, wherein the composition comprises 20 to 50 wt% of adsorbent, 45 to 80 wt% of dimethylpolypropoxymethylammonium chloride, and 0 to 10 wt. The first composition of the % acrylic adhesive is further applied to the top surface of the frame of the photomask protective film assembly as an adhesive for bonding to the transparent film.