TWI676076B - Photomask, method for manufacturing photomask, and semiconductor photomask substrate - Google Patents

Abstract

A method for manufacturing a photomask includes: providing a semiconductor photomask substrate. The semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, a first hard mask layer, and a second hard mask on a substrate. A mask layer and a photoresist layer; patterning the photoresist layer to form an opening; removing the second hard mask layer exposed in the opening; patterning the first hard mask layer to remove the exposed first hard mask layer; removing A photoresist layer on a second hard mask layer; an etching mask using the remaining second hard mask layer and the first hard mask layer as absorption layers, patterning the absorption layer to remove the exposed absorption layer; The absorption layer is used as an etching mask for the phase shift layer, and the phase shift layer is patterned to remove the exposed phase shift layer; the remaining second hard mask layer and the first hard mask layer are removed; and the remaining absorption layer is removed.

Description

Photomask, photomask manufacturing method, and semiconductor photomask substrate

The present invention relates to a photomask, a method for manufacturing the photomask, and a semiconductor photomask substrate.

In the current optical lithography (Lithography) technology, the deep ultraviolet (DUV) or extreme ultraviolet (EUV) exposure technology of the Reticle on the wafer photoresist layer can be mainly divided into binary chromium film masks and Phase shift mask (Phase Shift Mask) two. Binary chromium film masks mainly use chromium and its compounds as the light blocking material; phase shift masks reduce the problems caused by diffraction phenomena, thereby increasing image contrast and improving resolution. The phase shift material is added to make the light phases of two adjacent transparent areas opposite to each other, causing destructive interference of diffracted light and weakening the light intensity of the opaque areas. Therefore, the original contrast is strengthened, making the original unresolvable The area becomes resolvable.

Please refer to FIG. 1. In a conventional phase-shifting mask optical lithography technique, the phase-shifting layer 12, the absorbing layer 13, and the photoresist layer 16 are sequentially disposed on the substrate 11 of the mask M. Among them, When the plasma etching process is performed on the absorption layer 13, the oxygen radicals in the plasma will interact with the photoresist layer 16. In addition to reducing the material selectivity of the photoresist layer 16, the thickness of the photoresist layer 16 It also needs to be thicker (for example, 1000 Å, 1 Å = 10 ^-10 m), and the thicker photoresist layer 16 also easily causes sub-resolution assist feature (SRAF) poor development and pattern defects. The structure also has the problems of the reactive ion etching delay (RIE lag) and plasma incident angles effects, which make the resolution and uniformity of the prepared mask pattern poor.

The object of the present invention is to provide a photomask, a method for manufacturing the photomask, and a semiconductor photomask substrate. In addition to improving the selectivity of the photoresist layer, the thickness and etching deviation caused by the photoresist can be greatly reduced, and the reaction can be improved. Ion etch delay and plasma incident angle effect to improve the resolution and uniformity of the mask pattern.

To achieve the above object, the present invention provides a method for manufacturing a photomask, including: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, and a first A hard mask layer, a second hard mask layer, and a photoresist layer; patterning the photoresist layer to form an opening, wherein the second hard mask layer of the exposed portion of the opening; removing the second hard mask exposed in the opening Layer; using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the second hard mask layer Photoresist layer; using the remaining second hard mask layer and the first hard mask layer as an etching mask for the absorption layer, patterning the absorption layer to remove the exposed absorption layer; using the remaining absorption layer as a phase shift layer Etching the mask, patterning the phase shift layer to remove the exposed phase shift layer; removing the remaining second hard mask layer and the first hard mask layer; and removing the remaining absorbing layer.

In one embodiment, the thickness of the first hard mask layer is between 30 Angstroms (Å) and 90 Angstroms.

In one embodiment, the first hard mask layer is oxidized by a thermal oxidation process to form a second hard mask layer. The thickness of the second hard mask layer is between 20 Angstroms (Å) and 40 Angstroms.

In one embodiment, the first hard mask layer and the second hard mask layer are sequentially formed on the absorption layer by a deposition process.

In one embodiment, the thickness of the photoresist layer is between 200 Angstroms (Å) and 400 Angstroms.

In one embodiment, in the step of removing the exposed second hard mask layer, a wet etching process is used, and the exposed second hard mask layer is removed with 5% hydrofluoric acid after photoresist development.

In one embodiment, in the step of patterning the first hard mask layer to remove the exposed first hard mask layer, it is completed by multiple atomic layer etch (ALE) processes. .

In one embodiment, each atomic layer etching process includes: making chlorine radicals Adsorb on the surface of the first hard mask layer to form multiple silicon-chlorine (Si-Cl) bonds by bonding with the atoms on the surface; remove excess chlorine radicals; desorb these silicon chlorides by argon (Si-Cl) bonds; and removing excess argon ions and the silicon-chloride (Si-Cl) bonds.

In an embodiment, before the step of patterning the absorption layer to remove the exposed absorption layer, the method further includes: oxidizing the sides of the first hard mask layer with ozone water to form an oxide layer, wherein the thickness of the oxide layer is Between 10 Angstroms and 25 Angstroms.

In one embodiment, in the step of patterning the phase shift layer, the remaining second hard mask layer and the first hard mask layer are simultaneously removed.

To achieve the above object, the present invention provides a photomask, which is manufactured by using the aforementioned manufacturing method.

To achieve the above object, the present invention provides a semiconductor photomask substrate, which includes a substrate, a phase shift layer, an absorption layer, a silicon hard mask layer, a silicon dioxide hard mask layer, and a photoresist layer. The phase shift layer is disposed on the substrate. The absorbing layer is disposed on the phase shift layer. A silicon hard mask layer is disposed on the absorption layer. The silicon dioxide hard mask layer is disposed on the silicon hard mask layer. The photoresist layer is disposed on the silicon dioxide hard mask layer.

To achieve the above object, the present invention further provides a method for manufacturing a photomask, including: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a multilayer film layer, a cover layer, a Absorptive layer, a first hard mask layer, a second hard mask layer, and a photoresist layer; pattern the photoresist layer to form an opening, wherein the second hard mask layer of the exposed portion of the opening is removed; and the exposure is removed from the opening The second hard mask layer; using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the first hard mask layer; A photoresist layer on two hard mask layers; an etching mask using the remaining second hard mask layer and the first hard mask layer as absorption layers, patterning the absorption layer to remove the exposed absorption layer; and removing the remaining The second hard mask layer and the first hard mask layer.

To achieve the above object, the present invention further provides a photomask, which is manufactured by using the aforementioned manufacturing method.

To achieve the above object, the present invention further provides a semiconductor photomask substrate including a substrate, a multilayer film layer, a cover layer, an absorption layer, a silicon hard mask layer, a silicon dioxide hard mask layer, and A photoresist layer. A plurality of film layers are disposed on the substrate. The cover layer is disposed on the multilayer film layer. The absorbing layer is disposed on the cover layer. A silicon hard mask layer is disposed on the absorption layer. The silicon dioxide hard mask layer is disposed on the silicon hard mask layer. The photoresist layer is disposed on the silicon dioxide hard mask layer.

In one embodiment, the multilayer film is a molybdenum silicon multilayer film.

As mentioned above, in the photomask, the method for manufacturing the photomask, and the semiconductor photomask substrate of the present invention, the exposed second hard mask layer is removed through the opening of the photoresist layer, and the remaining second hard mask is removed. After the mask layer is used as an etching mask of the first hard mask layer, the first hard mask layer is patterned to remove the exposed first hard mask layer, and the remaining second hard mask layer and the first hard mask are then patterned. Layer as an etching mask of the absorption layer, and patterning the absorption layer to remove the exposed absorption layer, and then removing the remaining second hard mask layer and the first hard mask layer, a patterned phase shift on the substrate can be obtained Layer, or a mask with a phase shift layer, a cover layer, and a patterned absorption layer on the substrate. Therefore, since the first hard mask layer is patterned by using the second hard mask layer to define the shape of the first hard mask layer, the thickness of the photoresist layer can be greatly reduced, making the photoresist layer selective. The effect no longer exists, and the problems of etching deviation caused by photoresistance, reactive ion etching delay, and plasma incident angle effect can be improved, and the resolution and uniformity of the mask pattern can be improved.

11, 21, 31‧‧‧ substrate

12, 22‧‧‧ phase shift layer

13, 23, 33‧‧‧ absorbent layer

16, 26, 36‧‧‧ photoresist layer

2, 2a, 3, 3a ‧‧‧ semiconductor photomask substrate

24, 34‧‧‧The first hard mask layer

24b‧‧‧oxide

25, 25a, 25b, 25c, 35‧‧‧Second hard mask layer

261‧‧‧ opening

32a‧‧‧multi-layer film

24a, 34a‧‧‧ Silicone hard mask layer

25d, 35a‧‧‧ Silicon dioxide hard mask layer

37‧‧‧ Overlay

Ar + ‧‧‧ argon ion

Cl‧‧‧chlorine

Cl * ‧‧‧ chlorine radical

Si-Cl‧‧‧ Silicon chloride bond

M, Ma‧‧‧Mask

S01 to S09, T01 to T07‧‧‧ steps

FIG. 1 is a partial side view of a conventional semiconductor photomask substrate.

FIG. 2 is a schematic flowchart of a method for manufacturing a photomask according to an embodiment of the present invention.

FIG. 3A to FIG. 3M are process schematic diagrams of the manufacturing method of the photomask shown in FIG. 2, respectively.

FIG. 4 is a schematic diagram of a semiconductor mask substrate according to an embodiment of the present invention.

FIG. 5 is a schematic flowchart of a manufacturing method of a photomask according to another embodiment of the present invention.

FIG. 6A is a schematic diagram of a semiconductor mask substrate according to another embodiment of the present invention.

FIG. 6B is a schematic diagram of a photomask according to another embodiment of the present invention.

FIG. 7 is a schematic diagram of a semiconductor mask substrate according to another embodiment of the present invention.

Hereinafter, a photomask, a method for manufacturing the photomask, and a semiconductor photomask substrate according to preferred embodiments of the present invention will be described with reference to related drawings. The same components will be described with the same reference symbols.

Please refer to FIG. 2, FIG. 3A to FIG. 3M, wherein FIG. 2 is a schematic flow chart of a method for manufacturing a photomask according to an embodiment of the present invention, and FIGS. 3A to 3M are the photomask manufacturing methods shown in FIG. 2, respectively. Process schematic of the method.

In an embodiment of the present invention, the method for manufacturing a photomask may include the following steps: first, a semiconductor photomask substrate 2 is provided, wherein the semiconductor photomask substrate 2 sequentially includes a phase shift layer 22 on a substrate 21, An absorbing layer 23, a first hard mask layer 24, a second hard mask layer 25, and a photoresist layer 26 (step S01). As shown in FIG. 3A, the material of the substrate 21 may be quartz, optical glass, or sapphire. The material of the phase shifter layer 22 may be, for example, but not limited to, a molybdenum-silicon multilayer film (such as MoSiON), and may be, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD), or other suitable methods. It is formed on the base material 21. Absorber layer 23 is an absorber layer for deep ultraviolet light (DUV). The material may be, for example, but not limited to, chromium (Cr), chromium dioxide (CrO ₂ ), titanium, titanium tungsten, tungsten, silicon nitride. , Silicon dioxide, or titanium nitride, and is formed on the phase shift layer 22 by, for example, CVD, PVD, or other suitable methods. The material of the first hard mask layer 24 may be, for example, but not limited to, silicon (Si), and is formed on the absorption layer 23 by, for example, CVD, PVD, or other suitable methods. The aforementioned silicon may be a monocrystalline silicon, a polycrystalline silicon, or an amorphous silicon material, which is not limited. The thickness of the first hard mask layer 24 may be between 30 Angstroms (Å) and 90 Angstroms (30 Å ≦ thickness ≦ 90 Å). The material of the second hard mask layer 25 may be, for example, but not limited to, silicon dioxide (SiO ₂ ). The thickness of the second hard mask layer 25 may be between 20 Angstroms (Å) and 40 Angstroms (20Å ≦ thickness ≦ 40Å). ). In addition, the photoresist layer 26 may be formed on the second hard mask layer 25 by, for example, coating, printing, or other suitable methods. The thickness may be between 200 Angstroms (Å) and 400 Angstroms ( 200Å ≦ thickness ≦ 400Å), or the thickness of the photoresist layer 26 may be less than 200Å.

In one embodiment, the material of the substrate 21 is quartz; the material of the phase shift layer 22 is a molybdenum-silicon multilayer film (MoSiON) with a thickness of 690Å; the material of the absorption layer 23 is Cr or CrO ₂ with a thickness of 480Å; The material of the first hard mask layer 24 is Si and its thickness is 30 Å; the material of the second hard mask layer 25 is SiO ₂ and its thickness is 20 Å; and the thickness of the photoresist layer 26 is 200 Å. It is further mentioned that, in some embodiments, an upper layer of the first hard mask layer 24 (material, for example, Si) can be oxidized by a thermal oxidation process to make the first hard mask layer 24 The upper layer is oxidized to become the second hard mask layer 25 (the material is, for example, SiO ₂ ). In this case, the thickness of the first hard mask layer 24 formed on the absorption layer 23 may be, for example, 70 Å. After that, the upper hard part of the first hard mask layer 24 is oxidized by a thermal oxidation process to form a second hard mask. When the layer 25 is formed, the thickness of the second hard mask layer 25 may be, for example, 20 Å. At this time, the thickness of the first hard mask layer 24 is, for example, 30 Å (the remaining 20 Å disappearing is a process loss). Alternatively, in other embodiments, the first hard mask layer 24 and the second hard mask layer 25 may be sequentially formed on the absorption layer 23 by using a deposition process, respectively. The present invention does not limit the method.

Next, as shown in FIG. 3B, the photoresist layer 26 is patterned to form an opening 261, wherein the opening 261 exposes a portion of the second hard mask layer 25 (step S02). The "exposure" referred to in this embodiment refers to the part of a film layer that is not covered by other film layers, such as 25a, 25b, and 25c shown in FIG. 3B. In some embodiments, at least one opening 261 may be formed by patterning the photoresist layer 26 using Lithography technology. After that, the second hard mask layer 25 exposed in the opening 261 is removed (step S03). As shown in FIG. 3C, the exposed second hard mask layer 25, that is, 25a, 25b, and 25c has been removed to make the photoresist Only the second hard mask layer 25 is between the layer 26 and the first hard mask layer 24. In step S03 of removing the exposed second hard mask layer 25, for example, the exposed second hard mask layer may be removed by using a wet etching process and 5% hydrofluoric acid (HF) after photoresist development. 25.

After that, the remaining second hard mask layer 25 is used as an etching (hard) mask of the first hard mask layer 24, and the first hard mask layer 24 is patterned to remove the exposed first hard mask layer 24. (Step S04). In step S04 of removing the exposed first hard mask layer 24, plasma etching is used to complete the process by repeating the atomic layer etch (ALE) process. In this embodiment, the material of the first hard mask layer 24 is silicon, and each atomic layer etching process may include the following steps: First, as shown in FIG. 3D, the chlorine radical adsorption (Adsorption) A surface of a hard mask layer 24 is bonded with atoms on the surface of the first hard mask layer 24 to form a plurality of silicon-chlorine (Si-Cl) bonds. Here, the chlorine radicals (Cl ^* ) in the plasma are radiated toward the exposed first hard mask layer 24 (silicon), and the chlorine ions are bonded to the silicon atoms on the surface to form silicon chloride (Si-Cl). Bond structure; Next, as shown in FIG. 3E, excess chlorine radicals are purged. After that, as shown in FIG. 3F, argon ions (Ar ⁺ ) in the argon plasma are radiated toward the surface of the first hard mask layer 24 to desorb the aforementioned silicon-chlorine (Si-Cl) bonds. Knot. Finally, as shown in FIG. 3G, excess argon ions and silicon-chlorine (Si-Cl) bonds are removed (Purge). It can be found from FIG. 3G that when argon ions are irradiated onto the surface of the first hard mask layer 24 to desorb Si-Cl on the surface, limited Si atoms can be taken away, thereby reducing the Thickness, and then repeat the steps of the atomic layer etching process repeatedly, as shown in FIG. 3H, until the exposed first hard mask layer 24 is completely removed. Since the thickness that can be removed by each atomic layer etching process is only about 1Å to 3Å, in some embodiments, it is necessary to repeat the atomic layer etching process, such as 10 to 20 times, to completely remove the exposed first hard mask Cover layer 24.

After that, as shown in FIG. 3I, the photoresist layer 26 on the second hard mask layer 25 is removed (step S05). After that, the remaining second hard mask layer 25 and the first hard mask layer 24 are used as etching (hard) masks of the absorption layer 23, and the absorption layer 23 is patterned to remove the exposed absorption layer 23 (step S06). . However, before step S06, as shown in FIG. 3J, must first by ozone (O ₃₎ water to form a first layer of hard mask oxide layer 24b side oxide layer 24, a first hard mask to protect the The thickness of the layer 24 and the oxide layer 24b may be between 10Å and 25Å. In some embodiments, the first hard mask layer 24 can be immersed in ozone water, and the side surface of the first hard mask layer 24 can be oxidized with ozone water to form a very thin oxide layer (SiO ₂ ). Because the formed oxide layer is very thin, it will not affect the accuracy of subsequent processes. Here, the purpose of oxidizing the side surface of the first hard mask layer 24 to form silicon dioxide (SiO ₂ ) is to protect the first hard mask layer 24 (Si) and avoid the first hard mask in subsequent processes. The material of the cover layer 24 reacts with Cl ₂ or O ₂ in the dry etching plasma process to destroy its characteristics. The aforementioned ozone water contains, for example, an ozone (O ₃ ) concentration of 10 ppb to 20 ppb, and its action time may be, for example, between 10 seconds and 10 minutes.

After that, as shown in FIG. 3K, step S06 is performed: the remaining second hard mask layer 25 and the first hard mask layer 24 are used as etching masks for the absorption layer 23, and the absorption layer 23 is patterned by plasma etching. And the exposed absorption layer 23 is removed. Therefore, only the absorption layer 23 is located below the second hard mask layer 25 and the first hard mask layer 24, and the rest are removed. Next, the remaining absorption layer 23 is used as an etching mask for the phase shift layer 22, and the phase shift layer 22 is patterned to remove the exposed phase shift layer 22 (step S07); and the remaining second hard mask layer is removed. 25 and the first hard mask layer 24 (step S08). In step S07 and step S08 of this embodiment, as shown in FIG. 3L, the SF ₆ / O ₂ plasma etching can be used to remove the exposed phase shift layer 22, and at the same time, the second hard layer remaining on the phase shift layer 22 can be removed. The mask layer 25 and the first hard mask layer 24 are also removed at the same time. Finally, as shown in FIG. 3M, the remaining absorption layer 23 is removed (step S09) to obtain a patterned phase shift layer 22 on the substrate 21, and a photomask M is obtained.

Please refer to FIG. 4, which is a schematic diagram of a semiconductor mask substrate 2 a according to an embodiment of the present invention. The semiconductor photomask substrate 2a of this embodiment includes a substrate 21, a phase shift layer 22, an absorption layer 23, a Si hard mask layer 24a, and a silicon dioxide hard mask layer (SiO ₂ hard mask layer) 25d and a photoresist layer 36. The phase shift layer 22 is disposed on the substrate 21; the absorption layer 23 is disposed on the phase shift layer 22; the silicon hard mask layer 24a is provided on the absorption layer 23; the silicon dioxide hard mask layer 25d is provided on the silicon hard mask layer 24a; a photoresist layer 36 is disposed on the silicon dioxide hard mask layer 25d. For other technical features of the film layer of the semiconductor photomask substrate 2a, reference may be made to the same component names and their technical contents as described above, which will not be repeated here.

FIG. 5 is a schematic flowchart of a photomask manufacturing method according to another embodiment of the present invention, FIG. 6A is a schematic view of a semiconductor photomask substrate according to another embodiment of the present invention, and FIG. 6B is a photomask of another embodiment of the present invention. schematic diagram.

As shown in FIG. 5, the manufacturing method of the photomask Ma in this embodiment may include the following steps. As shown in FIG. 6A, step T01 is to provide a semiconductor photomask substrate 3, wherein the semiconductor photomask substrate 3 is sequentially included in a semiconductor photomask substrate 3. A multilayer film layer 32a, a capping layer 37, an absorption layer 33, a first hard mask layer 34, a second hard mask layer 35, and a photoresist layer 36 on the substrate 31; Step T02 is: patterning the photoresist layer 36 to form an opening, in which the second hard mask layer 35 of the exposed portion is removed; step T03 is: removing the second hard mask layer 35 exposed in the opening; step T04 is: The remaining second hard mask layer 35 is used as an etching mask for the first hard mask layer 34. The first hard mask layer 34 is patterned to remove the exposed first hard mask layer 34. Step T05 is: removing the second Photoresist layer 36 on the hard mask layer 35; Step T06 is: using the remaining second hard mask layer 35 and the first hard mask layer 34 as an etching mask for the absorption layer 33, and patterning the absorption layer 33 to remove The exposed absorbing layer 33 and step T07 are: removing the remaining second hard mask layer 35 and the first hard mask layer 34 (step T07).

Therefore, as shown in FIG. 6B, a photomask Ma having a multilayer film layer 32a, a cover layer 37, and a patterned absorption layer 33 on the substrate 31 can be obtained. The technical content of steps T01,..., T06, and T07 may refer to the contents of steps S01,..., S06, and S08 correspondingly, and details are not described herein again. In one embodiment, the multilayer film layer 32a may be a molybdenum-silicon multilayer film (eg, MoSi). In an embodiment, the material of the cover layer 37 is ruthenium (Ru), and the thickness thereof is 20Å.

Please refer to FIG. 7, which is a schematic diagram of a semiconductor photomask substrate 3 a according to another embodiment of the present invention. The semiconductor photomask substrate 3a of this embodiment includes a substrate 31, a multilayer film layer 32a, a cover layer 37, an absorption layer 33, a silicon hard mask layer 34a, a silicon dioxide hard mask layer 35a, and A photoresist layer 36. The substrate 31 is made of LTM, such as low thermal expansion quartz; the multilayer film layer 32a may be a molybdenum silicon multilayer film (such as MoSi), and is disposed on the substrate 31; the cover layer 37 is disposed on the multilayer film layer 32a; The absorption layer 33 is an extreme ultraviolet (EUV) absorption layer. The material is, for example, TaNO or TaN, and is disposed on the cover layer 37. A silicon hard mask layer 34a is provided on the absorption layer 33. A silicon dioxide hard mask layer 35a. The photoresist layer 36 is disposed on the silicon hard mask layer 34a. The photoresist layer 36 is disposed on the silicon dioxide hard mask layer 35a. In addition, for other technical features of the film layer of the semiconductor photomask substrate 3a, reference may be made to the same component names and their technical contents as described above, and no further description is given here.

According to the above, the photomask and photomask manufacturing method of the above embodiments have the following characteristics: The first point is that when atomic layer etching (ALE) is used to pattern the first hard mask layer, a second hard mask is used Layer to define the shape of the first hard mask layer instead of the photoresist layer, so the thickness of the photoresist layer can be greatly reduced (for example, it can be reduced by 80%), so that the selective effect of photoresist no longer exists; and the photoresist If the thickness of the layer is greatly reduced, the resolution of the mask pattern can be greatly improved. Second, due to the reduction of the effects of reactive ion etching delay, plasma incident angle, and overall loading of the hard mask, better pattern transfer fidelity (better uniformity / linearity) can be obtained. Third, while using the plasma etching to remove the exposed phase shift layer, the hard mask (the remaining second hard mask layer and the first hard mask layer) can be removed together, so the process cost is not increased.

In summary, in the photomask, the photomask manufacturing method, and the semiconductor photomask substrate of the present invention, the exposed second hard mask layer is removed through the opening of the photoresist layer, and the remaining second hard mask is removed. After the mask layer is used as an etching mask of the first hard mask layer, the first hard mask layer is patterned to remove the exposed first hard mask layer, and the remaining second hard mask layer and the first hard mask are then patterned. Layer as an etching mask of the absorption layer, and patterning the absorption layer to remove the exposed absorption layer, and then removing the remaining second hard mask layer and the first hard mask layer, a patterned phase shift on the substrate can be obtained Layer, or a mask with a phase shift layer, a cover layer, and a patterned absorption layer on the substrate. Therefore, since the first hard mask layer is patterned by using the second hard mask layer to define the shape of the first hard mask layer, the thickness of the photoresist layer can be greatly reduced, making the photoresist layer selective. The effect no longer exists, which can improve the light The problems of etching deviation caused by resistance, reactive ion etching delay and plasma incident angle effect can further improve the resolution and uniformity of the mask pattern.

The above description is exemplary only, and not restrictive. Any equivalent modification or change made without departing from the spirit and scope of the present invention shall be included in the scope of the attached patent application.

Claims (11)

A method for manufacturing a photomask includes: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, a first hard mask layer, and a first Two hard mask layers and a photoresist layer; patterning the photoresist layer to form an opening, wherein the second hard mask layer of an exposed portion of the opening; removing the second hard mask layer exposed in the opening; Using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the second hard mask The photoresist layer on the mask layer; using the remaining second hard mask layer and the first hard mask layer as etching masks of the absorption layer, patterning the absorption layer to remove the exposed absorption layer; The remaining absorption layer serves as an etching mask for the phase shift layer, patterning the phase shift layer to remove the exposed phase shift layer; removing the remaining second hard mask layer and the first hard mask layer; and The remaining absorption layer is removed; wherein the thickness of the first hard mask layer is between 30 Angstroms (Å) and 90 Angstroms. A method for manufacturing a photomask includes: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, a first hard mask layer, and a first Two hard mask layers and a photoresist layer; patterning the photoresist layer to form an opening, wherein the second hard mask layer of an exposed portion of the opening; removing the second hard mask layer exposed in the opening; Using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the second hard mask The photoresist layer on the mask layer; using the remaining second hard mask layer and the first hard mask layer as etching masks of the absorption layer, patterning the absorption layer to remove the exposed absorption layer; The remaining absorption layer serves as an etching mask for the phase shift layer, patterning the phase shift layer to remove the exposed phase shift layer; removing the remaining second hard mask layer and the first hard mask layer; and Removing the remaining absorption layer; wherein the first hard mask layer is oxidized by a thermal oxidation process to form The second hard mask layer, the second hard mask layer having a thickness between 20 Å and 40 Å. A method for manufacturing a photomask includes: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, a first hard mask layer, and a first Two hard mask layers and a photoresist layer; patterning the photoresist layer to form an opening, wherein the second hard mask layer of an exposed portion of the opening; removing the second hard mask layer exposed in the opening; Using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the second hard mask The photoresist layer on the mask layer; using the remaining second hard mask layer and the first hard mask layer as etching masks of the absorption layer, patterning the absorption layer to remove the exposed absorption layer; The remaining absorption layer serves as an etching mask for the phase shift layer, patterning the phase shift layer to remove the exposed phase shift layer; removing the remaining second hard mask layer and the first hard mask layer; and The remaining absorption layer is removed; wherein the thickness of the photoresist layer is between 200 and 400 angstroms. A method for manufacturing a photomask includes: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, a first hard mask layer, and a first Two hard mask layers and a photoresist layer; patterning the photoresist layer to form an opening, wherein the second hard mask layer of an exposed portion of the opening; removing the second hard mask layer exposed in the opening; Using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the second hard mask The photoresist layer on the mask layer; using the remaining second hard mask layer and the first hard mask layer as etching masks of the absorption layer, patterning the absorption layer to remove the exposed absorption layer; The remaining absorption layer serves as an etching mask for the phase shift layer, patterning the phase shift layer to remove the exposed phase shift layer; removing the remaining second hard mask layer and the first hard mask layer; and Removing the remaining absorbing layer; wherein the first hard mask layer is patterned to remove the exposed first hard mask layer Step cap layer, is repeated several times by an atomic layer etching process to complete. The manufacturing method according to item 4 of the scope of patent application, wherein each of said atomic layer etching processes comprises: causing chlorine radicals to be adsorbed on a surface of said first hard mask layer to form a plurality of silicon by bonding with atoms on the surface Chlorine (Si-Cl) bonds; removal of excess chlorine radicals; desorption of the silicon-chloride (Si-Cl) bonds by argon ions; and removal of excess argon ions and the silicon-chloride (Si- Cl) bond. The manufacturing method according to item 4 of the scope of patent application, wherein in the step of removing the exposed second hard mask layer, a wet etching process is used, and the exposure is removed with 5% hydrofluoric acid after photoresist development. The second hard mask layer. A method for manufacturing a photomask includes: providing a semiconductor photomask substrate, wherein the semiconductor photomask substrate sequentially includes a phase shift layer, an absorption layer, a first hard mask layer, and a first Two hard mask layers and a photoresist layer; patterning the photoresist layer to form an opening, wherein the second hard mask layer of an exposed portion of the opening; removing the second hard mask layer exposed in the opening; Using the remaining second hard mask layer as an etching mask for the first hard mask layer, patterning the first hard mask layer to remove the exposed first hard mask layer; removing the second hard mask The photoresist layer on the mask layer; using the remaining second hard mask layer and the first hard mask layer as etching masks of the absorption layer, patterning the absorption layer to remove the exposed absorption layer; The remaining absorption layer serves as an etching mask for the phase shift layer, patterning the phase shift layer to remove the exposed phase shift layer; removing the remaining second hard mask layer and the first hard mask layer; and Removing the remaining absorption layer; wherein the step of patterning the absorption layer to remove the exposed absorption layer Before, further comprising: an ozone water by the side of the first hard mask oxide layer to form an oxide layer, wherein the thickness of the oxide layer is between 10 Å and 25 Å. A photomask is manufactured by using the manufacturing method according to any one of claims 1 to 7 of the scope of patent application. A semiconductor photomask substrate includes: a substrate; a phase shift layer disposed on the substrate; an absorption layer disposed on the phase shift layer; a silicon hard mask layer disposed on the absorption layer; A silicon dioxide hard mask layer is disposed on the silicon hard mask layer; and a photoresist layer is disposed on the silicon dioxide hard mask layer. A semiconductor photomask substrate includes: a substrate; a multilayer film layer disposed on the substrate; a cover layer disposed on the multilayer film layer; an absorption layer disposed on the cover layer; a silicon hard A mask layer is disposed on the absorbing layer; a silicon dioxide hard mask layer is disposed on the silicon hard mask layer; and a photoresist layer is disposed on the silicon dioxide hard mask layer. The semiconductor photomask substrate according to item 10 of the application, wherein the multilayer film layer is a molybdenum-silicon multilayer film layer.