JP2012216846A - Method for forming semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a semiconductor element which achieves a pad layout that is hard to achieve an interconnection region, and can increase an overlay margin.SOLUTION: The method for forming the semiconductor element includes: forming a layer to be etched, a first hard mask material layer, a first division pattern material layer and a second hard mask material layer on a semiconductor substrate; selecting and etching the second hard mask material layer to form a second hard mask pattern; etching the first division pattern material layer by using the second hard mask pattern as a mask to form a first division pattern; forming a spacer material layer and a second division pattern material layer on the upper part of the first hard mask material layer, partially etching the spacer material layer and the second division pattern material layer until the first division pattern appears, exposing the spacer material layer, and forming a second division pattern between the plurality of the first division patterns; and etching the spacer material layer and the first hard mask material layer by using the first and second division patterns as a mask to form a first hard mask pattern, and etching the layer to be etched by using the first hard mask pattern as a mask to form a fine pattern.

Description

  The present invention relates to a method of forming a semiconductor device, and more particularly to increase an overlay margin during a manufacturing process in implementing a pad layout in which an interconnection region is difficult to implement when applying a negative tone SPT method. The present invention relates to a method for forming a semiconductor element capable of forming a semiconductor device.

Along with the high integration of semiconductor elements, the size and pitch of a pattern that embodies a circuit constituting the semiconductor element is gradually reduced. Considering the Rayleigh equation, the size of the fine pattern in the semiconductor device is proportional to the wavelength of light used in the exposure process and inversely proportional to the size of the lens. Therefore, a method of reducing the wavelength of light used in the exposure process or increasing the size of the lens has been mainly used so far for forming a fine pattern.
Furthermore, the photographic process technology in the processing process has been developed by developing a new photosensitizer and a high numerical aperture lens by adjusting the amount of light emitted through the mask by elaborating the mask design. Efforts such as the development of scanners to be used and the development of deformed masks have overcome the technical limitations of semiconductor device manufacturing equipment.
However, it is difficult to form a desired pattern width and interval due to the limitations of exposure and resolution capability performed using currently used light sources such as KrF and ArF. As an example, an exposure technique capable of manufacturing a pattern size of about 60 nm has been developed so far, but it is difficult to manufacture a pattern size smaller than that.

Here, various researches for forming a photosensitive film pattern having a fine pattern size and interval are continued. One of them is a DPT (Double Patterning Technology) method in which a pattern is formed by performing two photographic processes.
In the DPT method, DE2T (Double Expose) is used in which a pattern having a period twice as long as the pattern period is exposed and etched, and then a second pattern having a period twice as long is exposed and etched in the meantime. Etch Technology) method and SPT (Spacer Patterning Technology) method for forming a pattern using a spacer. The DE2T method and the SPT method can be formed in a negative tone (positive tone) step and a positive tone (positive tone) step, respectively.
The negative tone DE2T method is a method in which the pattern formed in the first mask process is removed in the second mask process to form a desired pattern. The positive tone DE2T method is the first mask process and the second mask process. This is a method for forming a desired pattern by combining the patterns formed in the mask process. However, the DE2T method, which can obtain the desired pattern integration degree by performing the second mask process and the etching process after the first mask process and the etching process, has two mask processes and an etching process. The disadvantage is that the number of additional steps required to perform increases the process complexity. Furthermore, there is a possibility that a matching error occurs in the pattern obtained through the first mask process and the second mask process, which are usually called overlays, and are independent from each other.

On the other hand, the SPT method is a self-alignment method that can prevent a misalignment defect because a mask process is performed only once for patterning a cell region. However, in order to form a pad pattern in the core and the peripheral circuit region, an additional mask process for separating the pattern portion of the mat edge region is necessary, and the deposition uniformity in the spacer formation region is required. ) And CD control starting from the spacer formation etching process is not easy, so CD uniformity becomes a problem.
The NAND flash process with many layers of lines / spaces can be developed by applying the SPT method alone, but if the DRAM brick wall pattern and the pattern are complicated layers, the SPT method can be used. Since the pattern cannot be formed, there is a problem that the DE2T process must be applied.

The present invention utilizes the basic principle that when applying the negative tone SPT method, the final profile of the gap fill poly formed between the spacer deposition materials is formed in a line. It is an object of the present invention to provide a method of forming a semiconductor device that can implement a pad layout that is difficult to implement.
Furthermore, the present invention can apply a dry etchback or wet removal process when removing the gap fill poly so that the spacer deposition material is exposed, and thus a method of forming a semiconductor device that can increase an overlay margin. There is a purpose to provide.

  A method of forming a semiconductor device according to the present invention includes: sequentially forming an etched layer, a first hard mask material layer, a first divided pattern material layer, and a second hard mask material layer on a semiconductor substrate; A step of selectively etching the second hard mask material layer to form a second hard mask pattern; and using the second hard mask pattern as an etching mask, the first divided pattern material layer Forming a first divided pattern, and forming a spacer material layer and a second divided pattern material layer on the first hard mask material layer including the first divided pattern. Until the first divided pattern appears, the spacer material layer and the second divided pattern material layer are partially etched to expose the spacer material layer, and a plurality of the first divided patterns are interposed between the plurality of first divided patterns. No. 2 Forming a division pattern, and etching the spacer material layer and the first hard mask material layer using the first division pattern and the second division pattern as an etching mask, Forming a hard mask pattern; and etching the etched layer using the first hard mask pattern as an etching mask to form a fine pattern.

Further, the step of forming the second hard mask pattern includes applying a photosensitive film on the second hard mask pattern material layer, and exposing the photosensitive layer having a pitch twice the desired pitch through an exposure and development process. Forming a film pattern; and etching the second hard mask material layer using the photosensitive film pattern as an etching mask.
The method further includes forming a silicon oxynitride film on the second hard mask pattern material layer.
The method further includes forming a lower antireflection film on the silicon oxynitride film.
The second hard mask material layer is formed of amorphous carbon.
Also, the first hard mask material and the spacer material are formed of the same material.
Further, the step of forming the first division pattern may match the height of the first division pattern and the thickness of the spacer material layer so that the first hard mask material layer is as thick as the spacer material layer. The method further includes partial etching.
The first hard mask material layer and the spacer material layer are formed of TEOS.
Further, the first divided pattern and the second divided pattern are formed of the same material.
Further, the first divided pattern material layer and the second divided pattern material layer are formed of polysilicon.
Further, when the second divided pattern material layer is formed to have a uniform thickness, the step of forming the second divided pattern material includes partially etching the second divided pattern material layer to a constant thickness. The method further includes the step of:
In addition, the spacer material layer and the second divided pattern material layer are partially etched through dry etchback, wet removal, or a CMP process.
Further, when the second divided pattern material layer is deposited so as to have a flat surface, the step of forming the second divided pattern includes the first hard mask layer including the first divided pattern. Coating a photosensitive film on the upper surface of the substrate, forming a photosensitive film pattern that covers an area where the first divided pattern and the second divided pattern are to be formed through exposure and development processes; A step of etching the second divided pattern material layer using an engraved mask.

  A method of forming a semiconductor device according to the present invention includes a step of forming an etched layer on an upper portion of a semiconductor substrate on which a lower structure is formed, and forming a first mask material layer on the etched layer. A step of selectively etching the first mask material layer to form a first mask pattern including a pad pattern and a line pattern; and a line pattern formed between the plurality of first mask patterns. Forming a second mask pattern; forming a third mask pattern interconnecting the pad pattern of the first mask pattern and the second mask pattern; the first mask pattern; Etching the etching layer using the second mask pattern and the third mask pattern as an etching mask to form a fine pattern.

Forming the second mask pattern includes forming a spacer material layer on the etched layer including the first mask pattern; and forming a second mask on the spacer material layer. Forming a material layer; and partially etching the second mask material layer.
Further, in the step of forming the second mask pattern, the pad pattern of the first mask pattern is formed in a bowl shape, and the second mask pattern is formed in a bowl shape.

The present invention uses the basic principle that a final profile of a gap fill poly formed between spacer deposition materials is formed by a line when applying a negative tone SPT method. The effect that the layout can be realized is obtained.
In addition, the present invention has an advantage that an overlay margin can be increased because a dry etchback or wet removal process can be applied when removing the gap fill poly so that the spacer deposition material is exposed.

It is sectional drawing which showed the negative tone SPT method. It is sectional drawing which showed the negative tone SPT method. It is sectional drawing which showed the negative tone SPT method. It is sectional drawing which showed the negative tone SPT method. It is sectional drawing which showed the negative tone SPT method. It is sectional drawing which showed the negative tone SPT method. It is sectional drawing which showed the negative tone SPT method. It is a top view for demonstrating the cell area | region of flash memory. It is the top view and sectional drawing which showed the manufacturing method which forms a fine circuit pattern through the negative tone SPT method concerning this invention. It is the top view and sectional drawing which showed the manufacturing method which forms a fine circuit pattern through the negative tone SPT method concerning this invention. It is the top view and sectional drawing which showed the manufacturing method which forms a fine circuit pattern through the negative tone SPT method concerning this invention. It is the top view and sectional drawing which showed the manufacturing method which forms a fine circuit pattern through the negative tone SPT method concerning this invention. It is the top view and sectional drawing which showed the manufacturing method which forms a fine circuit pattern through the negative tone SPT method concerning this invention. It is the top view and sectional drawing which showed the manufacturing method which forms a fine circuit pattern through the negative tone SPT method concerning this invention. FIG. 6 is a plan view showing a manufacturing method for forming a fine circuit pattern through a negative tone SPT method according to another embodiment of the present invention. FIG. 6 is a plan view showing a manufacturing method for forming a fine circuit pattern through a negative tone SPT method according to another embodiment of the present invention. FIG. 6 is a plan view showing a manufacturing method for forming a fine circuit pattern through a negative tone SPT method according to another embodiment of the present invention. FIG. 6 is a plan view showing a manufacturing method for forming a fine circuit pattern through a negative tone SPT method according to another embodiment of the present invention. FIG. 6 is a plan view showing a manufacturing method for forming a fine circuit pattern through a negative tone SPT method according to another embodiment of the present invention. FIG. 6 is a plan view showing a manufacturing method for forming a fine circuit pattern through a negative tone SPT method according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 (a) to FIG. 1 (g) are cross-sectional views showing a negative tone spacer patterning technology (SPT) method. Here, a case where a control gate of a flash memory is formed will be described as an example.
As shown in FIG. 1 (a), after forming an element isolation film defining an active region on a semiconductor substrate, ONO dielectric film / gate poly / tungsten silicide (WSi), etc. are deposited and formed in the lower part. A capping first silicon oxynitride film (SiON) 110 is formed on the structure.
A first TEOS 112 and a first poly 114 are deposited on the first silicon oxynitride film 110 as a hard mask. Here, the height of the hard mask formed of the first poly 114 determines the height of the spacer used as a partition pattern, which is one of the cores of the SPT process.
However, since the first poly 114 cannot be etched in the photosensitive film pattern, the first amorphous carbon 116 and the second silicon oxynitride film 118 are used as a hard mask for etching the first poly 114. Formed on top of poly 114. Next, a bottom anti-reflected coating (BARC) layer 119 is formed on the second silicon oxynitride film 118.
A photosensitive film is applied on the BARC 119, and a photosensitive film pattern 120 is formed on the photosensitive film through exposure and development processes using a mask in which a pattern having a pitch twice the desired pitch is defined. . For example, when the etching bias is not considered, if the line is formed with 40 nm CD (Critical Dimension), the space is formed with 120 nm CD. That is, the line / space ratio is set to 1: 3.

  As shown in FIG. 1B, the BARC 119, the second silicon oxynitride film 118, the first amorphous carbon 116, and the first poly 114 are formed using the photoresist pattern 120 as an etching mask. The first poly pattern 114a is formed by sequentially etching, and the photosensitive film pattern 120, the BARC 119, the second silicon oxynitride film 118, and the first amorphous carbon 116 are removed. At this time, the upper portion of the first TEOS 112, which is a hard mask, is partially etched to the height of the first poly pattern 114a. The reason for the etching is to make the height of the first poly pattern 114a and the thickness of the spacer formed of TEOS (Tetraethyl Orthosilicate) above the first TEOS 112 the same. If the height of the first poly pattern 114a and the thickness of the spacer are not the same, the etching selectivity changes depending on the material constituting the etching mask in the subsequent process of etching the spacer, and the etching profile (profile) ) May change.

  As shown in FIG. 1C, a second TEOS 122 used as a spacer material is deposited on top of the first TEOS 112, which is a hard mask including the first poly pattern 114a. Furthermore, when the second TEOS 122 is not deposited at a temperature lower than the deposition temperature of the first TEOS 112, which is the first poly pattern 114a and the lower hard mask, film lifting due to thermal stress is later performed. lifting) cannot be prevented. In addition, since the deposition material used as the spacer has a large effect on the line width, it is best to use the second TEOS 122 with excellent step coverage, but it should be used for the ALD (Atomic Layer Deposition) method. It is also possible to use substances that can

  As shown in FIGS. 1D and 1E, a gap fill hard mask second poly 124 is formed on the second TEOS 122, and an etch back process is performed on the second poly 124. At this time, if the second poly 124 is not sufficiently deposited so as to have a uniform flat surface regardless of the region where the fine first poly pattern 114a is formed, the second TEOS 122, which is a spacer material, is exposed. Thus, when a certain depth is etched, the second poly pattern 124a as shown in FIG. 1 (e) cannot be formed.

  As shown in FIG. 1 (f), the second TEOS 122 is partially etched to expose the first poly pattern 114a, and the gap fill hard mask formed between the second TEOS 122, which is a spacer material, is formed. The second poly pattern 124a forms a line pattern together with the first poly pattern 114a. Here, as a method of etching the second TEOS 122, a dry etch back method and a wet strip method are applied.

As shown in FIG. 1 (g), using the first poly pattern 114a and the second poly pattern 124a as an etching mask, the first TEOS 112 and the second TEOS 122 as a spacer are etched. First TEOS pattern 112a and second TEOS pattern 122a are formed, respectively.
Thereafter, using the first TEOS pattern 112a and the second TEOS pattern 122a as an etching mask, the first silicon oxynitride film 110 is etched to form a fine pattern having a small pitch that cannot be formed with existing exposure equipment. Form. FIG. 2 is a plan view for explaining a cell region of a flash memory. Specifically, a plurality of control gates included in the cell region are formed in a line pattern, and are referred to as a source selection line or a drain selection line. The interconnection region for connecting the two is formed in a pad shape located at both ends of the plurality of control gates.

  FIGS. 3A to 3G are a plan view and a cross-sectional view showing a manufacturing method for forming a fine circuit pattern through the negative tone SPT method according to the present invention. In particular, the case where the interconnection region of the control gate of the flash memory shown in FIG. 2 is formed will be described as an example.

As shown in FIG. 3 (a), after forming a device isolation film defining an active region on a semiconductor substrate, an ONO dielectric film / gate poly / tungsten silicide (WSi), etc. are deposited and embodied. A capping first silicon oxynitride film (SiON) 310 is formed on the top of the substrate.
A first TEOS 312 and a first poly 314 are deposited on the first silicon oxynitride film 310 as a hard mask.
Further, a first amorphous carbon 316 and a second silicon oxynitride film 318 are formed on the first poly 314 as a hard mask for etching the first poly 314.
A photosensitive film is applied on top of the second silicon oxynitride film 318, and the photosensitive film is exposed to light through exposure and development processes using a mask in which a pattern having a pitch twice the desired pitch is defined. A film pattern 320 is formed. At this time, in order to prevent the photoresist pattern 320 from being damaged during the exposure and development processes, a bottom anti-reflected coating (BARC) is formed between the second silicon oxynitride film 318 and the photoresist pattern 320. Can also be formed.

  As shown in the plan view, when the etching bias is not taken into consideration, the photoresist pattern 320 formed through the exposure and development process has a line to space ratio of 1: 3. For example, if the line is formed with a 40 nm CD, the space is formed with a 120 nm CD.

  As shown in FIG. 3B, the second silicon oxynitride film 318, the first amorphous carbon 316, and the first poly 314 are sequentially etched using the photoresist pattern 320 as an etching mask. Thus, the first poly pattern 314a is formed, and the remaining photosensitive film pattern 320, the second silicon oxynitride film 318, and the first amorphous carbon 316 are removed. At this time, in order to match the height of the first poly pattern 314a with the thickness of the spacer formed by TEOS, the first TEOS 312 that is a hard mask is partially etched by the thickness of the spacer.

  As shown in FIG. 3 (c), a second TEOS 322 used as a spacer material is deposited on the top of the first TEOS 312 including the first poly pattern 314a, and a gap fill hard is formed on the top of the second TEOS 322. A second mask poly 324 is formed. That is, the second TEOS 322 formed on the first poly pattern 314a has a bend as high as the first poly pattern 314a, and the second poly 324 is embedded in the bent low region of the second TEOS 322. Thereafter, an etch back process is performed on the second poly 324 to expose the upper portion of the first poly pattern 314a as shown in FIG. 3 (d).

  As shown in FIGS. 3 (c) and 3 (d), the second poly 324 is partially etched by the etch back method or the CMP (Chemical Mechanical Polishing) method with respect to the second poly 324. The pattern 314a is exposed to form a second TEOS pattern 322a.

  As shown in FIG. 3 (e), a photosensitive film is applied on top of the second poly pattern 324a including the first poly pattern 314a and the second TEOS pattern 322a, and the first poly pattern is exposed through an exposure and development process. A second photoresist pattern 326 is formed in which regions for forming 314a and the second poly pattern 324a are defined. At this time, in order to accurately form the pad configuration of the second poly pattern 324a, a mask process for forming the second photoresist pattern 326 must be strictly performed. Specifically, the boundary of the second photosensitive film pattern 326 is determined by a pair of two pad patterns, but in the horizontal direction (I-I '), the width of the two line patterns and the distance between the line patterns are determined. The vertical direction is determined in units of two pad patterns connected to two line patterns. As shown in FIG. 3 (f), the exposed portions of the exposed second poly pattern 324a and the exposed second TEOS pattern 322a are etched using the second photoresist pattern 326 as an etching mask. A second poly pattern 324a is formed, and the second photoresist pattern 326 is removed.

Thereafter, as shown in FIG. 3 (f), the exposed second TEOS pattern 322a and the first TEOS 312 are etched using the first poly pattern 314a and the second poly pattern 324a as an etching mask. Then, the first TEOS pattern 312a is formed on the first silicon oxynitride film 310.
Thereafter, the first silicon nitride oxide film 310 is etched using the first TEOS pattern 312a as an etching mask, and the fine pattern shown in FIG. 2 having a small pitch that cannot be formed with existing exposure equipment is formed. Form.

The fine pattern shown in FIG. 2 includes a plurality of unit patterns, and each unit pattern includes a line pattern corresponding to the control gate and a pad pattern corresponding to the interconnection region. In the fine pattern formed through FIGS. 3A to 3F, the first unit pattern, which is a part of the plurality of unit patterns, is formed corresponding to the first poly pattern 314a, and the other first patterns are formed. The two unit patterns are formed corresponding to the second poly patterns 324a, and in particular, the first unit patterns and the second unit patterns are alternately formed.

  In the above-described embodiment of the present invention, by using the second TEOS pattern 322a formed as a spacer as an etching mask, a fine circuit that could not be realized when patterning a photosensitive film through an exposure process. Manufacture is now possible. However, in FIG. 3E, there is a disadvantage that an operation margin is small during an etching process using the second photosensitive film pattern 326 to manufacture a pad form. Although the pitch between the pads is very narrow, since the second photosensitive film pattern 326 formed through the exposure process is used, misalignment is very likely to occur. If an alignment error occurs, the exposed second poly pattern 224a is not accurately etched, and the pad patterns in each fine circuit pattern are connected without being separated from each other. It is difficult to form a pad having a size.

4 (a) to 4 (f) are plan views showing a manufacturing method for forming a fine circuit pattern by a negative tone SPT method according to another embodiment of the present invention.
As shown in FIG. 4 (a), first and second shape patterns 420a, 420b different from those in FIG. 3 (a) are formed on the second silicon oxynitride film 418.

  As shown in FIGS. 4 (a) to 4 (f), an ONO dielectric film is formed under the second silicon oxynitride film 418 after forming an element isolation film defining an active region on the semiconductor substrate. 1st TEOS 412 as a hard mask on top of the first silicon oxynitride film (SiON) 410 and the first silicon oxynitride film 410 capping on the upper part of the lower structure embodied by depositing / gate poly / tungsten silicide (WSi) etc. As a hard mask for etching the first poly 414 and the first poly 414, first amorphous carbon (not shown) is formed. At this time, a lower antireflection film can be formed between the second silicon nitride oxide film 418 and the first and second shape patterns 420a and 420b.

  As shown in FIG. 4 (a), a photosensitive film is applied on the second silicon oxynitride film 418 and arranged between the control gate pattern and the control gate pattern having a pitch twice the desired pitch. The photosensitive film is exposed and developed using a mask in which a plurality of pad patterns are defined. Through this, a first shape pattern 420a including a line pattern in which a control gate is formed and a pad pattern in which an interconnection region is formed, and a second shape pattern 420b including only a part of the pad pattern without a line pattern, A first photosensitive film pattern 421 is formed. Here, the line / space ratio of the first photosensitive film pattern 420 is 1: 3. For example, if the etching bias is not considered, if the line is formed with 40 nm CD, the space is formed with 120 nm CD.

  As shown in FIG. 4B, the BARC, the second silicon nitride oxide film 418, the amorphous carbon, and the first poly 414 are sequentially etched using the first photosensitive film pattern 421 as an etching mask. Forming a first poly pattern 415 including a gate pattern 414a having a first shape pattern and a pad pattern 414b having a second shape pattern, and forming a first photoresist pattern 420, BARC, a second silicon nitride oxide film 418, and Amorphous carbon is removed. At this time, in the embodiment of the present invention, in order to match the height of the first poly pattern 415 and the thickness of the spacer formed by TEOS, the upper portion of the first TEOS 412 that is a hard mask is partially etched by the thickness of the spacer. To do.

As shown in FIG. 4 (c), a second TEOS (not shown) used as a spacer material is deposited on the top of the first TEOS 412 which is a hard mask including the first poly pattern 415, and the top of the second TEOS. A second poly which is a gap fill hard mask is formed. At this time, unlike the method shown in FIG. 1 (d) in which the second poly is sufficiently deposited so as to have a flat surface, the second poly is deposited to a uniform thickness on the second TEOS. The region where the first poly pattern 415 is formed is formed to be higher than the other region.
Thereafter, if a dry etchback or wet removal process is performed on the second TEOS and the second poly, the second poly formed at a low height in a wide area is removed, but the line between the first poly patterns 415 is removed. The second poly pattern 424a in the form will remain. Thereafter, as shown in FIG. 4D, the exposed second TEOS is etched so that only the first poly pattern 415 and the second poly pattern 424a remain on the first TEOS 412.

  As shown in FIG. 4 (e), a second photoresist pattern 428 is formed in a region where the pad pattern 414b of the first poly pattern 415 and the second poly pattern 424a having a line pattern shape are connected to each other. . Usually, the second mask process is used to connect the line and the pad part, and the SPT process is used for the device of the design rule according to the development limit with the existing equipment. ) Must be controlled to be less than 10 nm.

As shown in FIG. 4 (f), the first TEOS 412 as a spacer was etched using the first poly pattern 415, the second poly pattern 424a and the second photosensitive film pattern 428 as an etching mask. Thereafter, the first poly pattern 415, the second poly pattern 424a, the second photosensitive film pattern 428, and the second TEOS pattern 422a used for the etching mask are removed to form a first TEOS pattern 412a.
Thereafter, using the first TEOS pattern 412a as an etching mask, the first silicon oxynitride film 410 is etched to form a fine pattern having a small pitch that cannot be formed by existing exposure equipment. The fine pattern includes a plurality of unit patterns including a line pattern corresponding to the control gate and a pad pattern corresponding to the interconnection region, and as shown in FIGS. 4 (a) to 4 (f), A plurality of first unit patterns and a plurality of second unit pattern pad patterns corresponding to the first poly pattern 415 and a plurality of second unit pattern line patterns corresponding to the second poly pattern 424a are included. In addition, the pad pattern and the line pattern of the second unit pattern are connected through an etching process using a separate second photoresist pattern 428.

In the embodiment of the present invention shown in FIGS. 4A to 4F, the second poly pattern 424a formed between the second TEOS patterns 422a, which is a spacer material, is etched. The first silicon oxynitride is formed by connecting the second poly pattern 424a of the line shape and the pad pattern 414b of the control gate to each other by the second photosensitive film pattern 428 using the basic principle formed in a line shape via The film 410 is used as an etching mask for etching.
Therefore, compared to the embodiment of the present invention shown in FIGS. 3 (a) to 3 (f), each producing a plurality of fine circuit patterns each composed of a control gate pattern and an interconnect region. In another embodiment of the present invention shown in FIGS. 4 (a) to 4 (f), the fine circuit pattern located between the two fine circuit patterns is patterned only in the interconnect region through the exposure process. Since it is further formed by using the photosensitive film pattern, the overlay margin can be increased in the manufacturing process. That is, from the etching process using the second photosensitive film pattern 326 that must accurately define the pad region boundaries of the plurality of fine circuit patterns shown in FIG. The etching process using the second photosensitive film pattern 428 can easily secure a larger operation margin.

Specifically, a pad pattern 414b connected to the second poly pattern 424a formed as a line pattern in the fine circuit pattern is formed in a bowl shape, and an overlay margin is formed during the pad forming process in the second mask process. Increase. In particular, by attaching a hook-like pattern under the hook-shaped pad pattern 414b so as to be connected to the pad pattern 414b in the first poly pattern 415 and the second TEOS pattern 422a, In the wet removal process, it is possible to form a line pattern including the second poly pattern 424a having a bowl shape in which the second poly is etched.
Therefore, when applying the negative tone SPT method according to the present invention, it is difficult to implement an interconnection region by using a basic principle that a final profile of a gap fill poly formed between spacer deposition materials is formed by lines. A technique capable of implementing a pad layout is disclosed.
Further, the present invention discloses a technique capable of increasing the overlay margin because a dry etchback or wet removal process can be applied when removing the gap fill poly so that the spacer deposition material is exposed. In particular, when applying the negative tone SPT method according to the present invention, it is difficult to implement an interconnection region by using a basic principle that a final profile of a gap fill poly formed between spacer deposition materials is formed by lines. A pad layout can be implemented.
Further, the present invention can increase the overlay margin because a dry etchback or wet removal process can be applied when removing the gap fill poly so that the spacer deposition material is exposed.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the said embodiment, All the changes in the range which does not deviate from the technical scope to which this invention belongs are included.

110, 310, 410 1st silicon oxynitride film
112, 312, 412 1st TEOS
112a, 312a, 412a 1st TEOS pattern
114, 314, 414 1st poly
114a, 314a, 415 1st poly pattern
116, 316 1st amorphous carbon
118, 318, 418 Second silicon oxynitride film
119 Lower antireflection film
120, 320 Photosensitive film pattern
122, 322 2nd TEOS
122a, 322a, 422a 2nd TEOS pattern
124, 324 2nd poly
124a, 224a, 324a, 424a Second poly pattern
326, 428 Second photosensitive film pattern
414a Gate pattern
414b pad pattern
420, 421 First photosensitive film pattern
420a 1st shape pattern
420b Second shape pattern

Claims (16)

Sequentially forming an etched layer, a first hard mask material layer, a first divided pattern material layer, and a second hard mask material layer on a semiconductor substrate;
Selectively etching the second hard mask material layer to form a second hard mask pattern;
Etching the first divided pattern material layer using the second hard mask pattern as an etching mask, and forming a first divided pattern;
Forming a spacer material layer and a second divided pattern material layer on top of the first hard mask material layer including the first divided pattern;
Until the first division pattern appears, the spacer material layer and the second division pattern material layer are partially etched to expose the spacer material layer, and a second portion is formed between the plurality of the first division patterns. Forming a divided pattern of
Etching the spacer material layer and the first hard mask material layer using the first divided pattern and the second divided pattern as an etching mask to form a first hard mask pattern; ,
Forming a fine pattern by etching the etched layer using the first hard mask pattern as an etching mask. The step of forming the second hard mask pattern includes:
Applying a photosensitive film on the second hard mask pattern material layer, and forming a photosensitive film pattern having a pitch twice the desired pitch through an exposure and development process;
2. The method of forming a semiconductor device according to claim 1, further comprising: etching the second hard mask material layer using the photosensitive film pattern as an etching mask.   3. The method of forming a semiconductor device according to claim 2, further comprising a step of forming a silicon oxynitride film on the second hard mask pattern material layer.   4. The method of forming a semiconductor device according to claim 3, further comprising a step of forming a lower antireflection film on the silicon oxynitride film.   2. The method of forming a semiconductor device according to claim 1, wherein the second hard mask material layer is formed of amorphous carbon.   2. The method of forming a semiconductor device according to claim 1, wherein the first hard mask material and the spacer material are formed of the same material.   In the step of forming the first division pattern, in order to match the height of the first division pattern and the thickness of the spacer material layer, the first hard mask material layer is partially etched by the thickness of the spacer material layer. 7. The method for forming a semiconductor device according to claim 6, further comprising a step of engraving.   7. The method of forming a semiconductor device according to claim 6, wherein the first hard mask material layer and the spacer material layer are formed of TEOS.   2. The method of forming a semiconductor element according to claim 1, wherein the first divided pattern and the second divided pattern are formed of the same material.   10. The method of forming a semiconductor device according to claim 9, wherein the first divided pattern material layer and the second divided pattern material layer are formed of polysilicon.   When the second divided pattern material layer is formed to a uniform thickness, the step of forming the second divided pattern is a step of partially etching the second divided pattern material layer to a constant thickness. 2. The method of forming a semiconductor element according to claim 1, further comprising:   12. The method of claim 11, wherein the spacer material layer and the second divided pattern material layer are partially etched through dry etchback, wet removal, or a CMP process. When the second divided pattern material layer is deposited to have a flat surface, the step of forming the second divided pattern,
A photosensitive film is applied on top of the first hard mask layer including the first division pattern, and covers an area where the first division pattern and the second division pattern are formed through an exposure and development process. Forming a photosensitive film pattern;
2. The method of forming a semiconductor device according to claim 1, further comprising: etching the second divided pattern material layer using the photosensitive film pattern as an etching mask. Forming an etched layer on top of the semiconductor substrate on which the substructure is formed;
Forming a first mask material layer on the etched layer, selectively etching the first mask material layer to form a first mask pattern including a pad pattern and a line pattern;
Forming a second mask pattern including a line pattern formed between a plurality of the first mask patterns;
Forming a third mask pattern that connects the pad pattern of the first mask pattern and the second mask pattern to each other;
Etching the etched layer using the first mask pattern, the second mask pattern, and the third mask pattern as an etching mask, and forming a fine pattern. A method for forming a semiconductor element. Forming the second mask pattern comprises:
Forming a spacer material layer on top of the etched layer including the first mask pattern;
Forming a second mask material layer on top of the spacer material layer;
15. The method of forming a semiconductor device according to claim 14, further comprising a step of partially etching the second mask material layer.   15. The step of forming the second mask pattern, wherein the pad pattern of the first mask pattern is formed in a bowl shape, and the second mask pattern is formed in a bowl shape. A method for forming a semiconductor element as described.

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