TW381301B - Manufacturing method of binary mask with controllable critical dimension - Google Patents

Abstract

The present invention is characterized in providing a kind of manufacturing method of binary mask with controllable critical dimension which includes the steps: providing a quartz substrate covered with chromium film; employing photolithography process to form a photoresist pattern on the chromium film; employing plasma treatment on the photoresist pattern; wet-etching the chromium film with the photoresist pattern after plasma treatment as the mask; and removing the photoresist pattern to get a binary mask whose critical dimension is under control.

Description

V. Description of the invention (1) The present invention relates to a two-bit mask known as a two-position mask that is formed in place and is transferred to the containing shadow mask for etching in the first sequence of 1A. The critical size can be set to 14 °. The curtain is then patterned with a micro-chrome film, the chromium film covering the curtain, and the chromium film pieces. In order to make the picture ~ 1C, please use the wet etching on the light of the film 12 on the calculated surface, and finally apply the chrome film to the conventional two-bit picture. Refer to the stone element pattern provided in 1A for details. The manufacturing method of the rotary mask manufacturing method and the shadow mask manufacturing method will set a resist pattern to remove the exposed photoresist pattern for the subsequent fabrication of the semiconductor mask. The figure uses the chrome method on the Xi base 10 to move it into place, and it is a special method. It is based on the components of the pattern transfer photoresist pattern on the substrate, and then the chromium film is used to 'remove the element pattern' to obtain the required micro range in a system process. Known metal splash. Then, the photoresist pattern of the plating method on the surface of the film 12 is followed by a photolithography pattern. Referring to FIG. 1B, the photoresist pattern 4 is used as an etching mask, and the exposed chromium film 12 is removed by etching to form a chromium containing element pattern. Film 12 ,. Among them, because the line width is shrinking with the increase in the density of the element, the phenomenon of fairy heart ⑶ as shown in the figure will occur when the pattern is transferred to the chromium film. This under-cut value " a " and after development The shape of the photoresist, the thickness of the photoresist, the density of the pattern, the type of the pattern, and the critical size of the pattern are wide. Finally, please refer to Figure 1C, after removing the photoresist pattern 14, you can get a chromium containing Film pattern 12'-two-bit mask 16. However, the critical dimension control of the obtained chromium film pattern 1 2 ′ is not well controlled, and there is a slight error from the original designed element pattern, which will produce substantial results for the subsequent component fabrication.

C: \ ProgramFiles \ Patent \ 0503-3881-E.ptd page 4 5. Description of the invention (2) '. There are shortcomings in the above-mentioned two-dimensional mask manufacturing process, so a process to improve this disadvantage has been proposed, which is mainly after the development step in the process is completed. After the photoresist pattern, the electropolymerized photoresist pattern is used as a button engraving to remove the chrome film on the bare road. In this way, a chromium mold pattern with a U nder-cut value smaller than the conventional process can be obtained. The critical dimension of the two-dimensional mask is also better than that of Xi. To make this process clearer and more detailed ~ the 2Dit towel is explained in detail. First, please refer to FIG. 2A, and use a conventional metal bell quenching method to form a chromium film 22 on the provided quartz substrate 20. Then, the designed element pattern is transferred to the photoresist pattern 24 on the surface of the chromium film 22 by a lithography process. "Secondly, please refer to Figure 2B, using a plasma composed of oxygen / nitrogen (0.1 to 0.4) at a pressure of 50 to 100 mtorr, a DC bias of 10 to 50 v, and an energy of 30 The photoresist pattern 24 is processed under the condition of ~ 40W for one second, and a photoresist pattern 24 with a better pattern shape is obtained. Then, 'Please refer to FIG. 2C, using the photoresist pattern 24' as an etching mask 'using wet The exposed chrome mold 22 is removed by etching, the pattern is transferred to the chrome mold 22 and a chrome mold pattern 26 is obtained, where the symbol " b " is an under-cut value generated after etching. Finally, please refer to FIG. 2D After removing the photoresist pattern 24, a two-bit mask 28 containing a chrome pattern 26 can be obtained. However, although the above process has improved the under-cut phenomenon of the conventional process

C: \ ProgramFiles \ Patent \ 0503-3881-E.ptd page 5 V. Description of the invention (3) and the size of the pattern is increasing the critical size of the bit mask made of blunt gas and the photoresistance pattern Critical size, the invention can input pieces into a photoresist pattern of a computer, so as to cover the screen. The critical ruler causes the plasma case shape in the two-dimensional process to be engraved and undetected each and the nature of the case. A large number of special cases can be used. However, the improved narrow line width requirements no longer exist, so I developed The curtain process is necessary. Therefore, after the development step is completed, the photoresist pattern after the development is treated with oxygen gas is well controlled, so that the chrome film pattern defined by Γ-cut value can also be reduced to the minimum. In the two-dimensional mask manufacturing process, the critical dimensions are prepared by a most appropriate plasma treatment according to and compared with the storage in the computer. The critical dimensions are well satisfied to meet the component density. The invention can be effectively controlled in the two gas, nitrogen and case. In order to make it critical, the plasma processing has good control. In addition, the plasma processing sequence detects each data individually, and the two bits are individually processed and controlled according to the conditions. The feature of the present invention is to disclose a controllable threshold The manufacturing method of a two-dimensional mask with a size includes the steps of: providing a quartz substrate covered with a chromium film, and forming a photoresist pattern on the chromium film by a lithography process; and using oxygen / gas / passive gas to gather the pair The photoresist pattern is subjected to a treatment; the plasma-treated photoresist pattern is used as a mask to 'wet etch the chrome film; and removing the photoresist pattern' to obtain a critical size that is controlled Bit mask. The method for manufacturing a two-dimensional mask with controllable critical dimensions as described above, wherein the ratio of oxygen / nitrogen / blunt gas in the plasma mixed gas is 5/50 / 20sccm ~ 10/50 / 40sccm 'and it is suitable for use. The gas is, for example, argon or helium; in addition, the pressure during the plasma treatment is 10 to 30 mTorr.

C: \ Program Files \ Patent \ 0503-3881-E.ptd page 6 5. Description of the invention (4) The current bias is 6 0 40 seconds.

The processing time is 2 5 90V, and the energy is 3 ～ 4 ～ 0w. The element mask = critical… two-position quartz substrate; the lithography procedures are used to determine the threshold values of these road molds, and determine each Light :: Rate: ϊ Photoresistance pattern, and use this set of photopolymerization processing conditions on the two places of the light = bar: The photopolymerization treatment of the photoresist pattern is cover 1, wet center = film = = 阻Figure #, Get a critical size controlled: Bit 2 Act. As mentioned above, the two-dimensional mask with controllable critical size = the mask in which the oxygen / nitrogen / blunt gas method of the plasma mixed gas' or helium is used; the flow bias is 6 0 5/5/2 / 2Sccm ~ 10/50 / 40sccm, and it is applicable if there is an external 'pressure of 10 ~ 30mt two gas' 90V, and the energy is 30 ~ 4flw ^ ^ ± 40 seconds. The processing time of 40W ′ is 25 ~. In order to make the advantages and features of the present invention more obvious and easy to understand, the preferred embodiment will be described in detail with reference to the related drawings. A brief description of the drawings of this issue:, °. Figures 1A to 1C show the process. The conventional 2A to 2D picture shows the conventional two-dimensional mask screen section process—a two-dimensional mask cross-section system. The 3A to 3D chart shows the Process according to this hair mask profile. Mingzhi-the embodiment of the two

5. Description of the invention (5) Figure 4 shows the ⑶-detection chart (ADI-TAG) of 20 samples after development. Figure 5 shows the post-etch CD inspection pattern (AEI-TAG) after treating 20 samples in Figure * with oxygen / nitrogen plasma. Figure 6 does not show the post-etch CD inspection pattern (AEI_TAG) after treating the 20 samples in Figure 4 with oxygen / nitrogen / argon plasma. Figure 7 does not show the CD detection pattern (ASI-TAG) after removing the photoresist patterns of the 20 samples in Figure 6. Figures 8A to 8C show the CD values detected after individually testing five samples and then treating them with the gas plasma according to the present invention under different conditions. Example: First, referring to FIG. 3A, a quartz substrate 30 is provided, and then a chromium film 32 is formed on the quartz substrate 30 by a conventional metal subtractive plating process. Then, the designed element pattern is transferred to the photoresist pattern 34 on the surface of the chromium film 32 by a lithography program. Then, please refer to FIG. 3B, using a plasma composed of oxygen, nitrogen and argon to apply a plasma treatment to the surface of the above structure, wherein the ratio of oxygen / nitrogen / argon is (5/50 / 20sccm ~ 10 / 50 / 40sccm), and the pressure during the plasma treatment is 10 to 30 mtorr, the DC bias is 60 to 90 V, and, 30 to 40 W, and the processing time is 25 to 40 seconds. In addition to argon in plasma gas, helium can be used instead of argon. After the photoresist pattern 34 is processed by the plasma, it becomes a photoresist pattern 3 4 'having a better shape. Then, please refer to FIG. 3C. Photoresist pattern treated with plasma

V. Description of the invention (6) 34 is used as a mask for money engraving, and the exposed chrome mold 32 is removed by wet etching to form a chrome mold 36 containing the element pattern. Finally, after removing the photoresist pattern 34 ', a two-dimensional mask 38 with a critical dimension that is well controlled can be obtained, which can be used as a lithographic mask for subsequent component manufacturing processes. As shown in Figure 4, after using the lithography program to transfer the designed pattern to the photoresist pattern on the chromium film, the detector (KMS-3 0 0) was used to detect the ADI-TAG (After Developing Inspection-Target) CD value (Y-axis). It can be seen from the figure that the cd values of 20 samples are distributed between 0.6 ~ ου # m. At this time, if the 20 samples detected by the conventional process oxygen / nitrogen plasma are shown in Fig. 4 'after wet etching, then the tester (KMS _ 3 00) is used to test its AEI-TAG (After CD value of Etching Inspection-Target). The results are shown in Figure 5. 'The aei value distribution curve of the 20 samples is consistent with Figure 4.' The distribution range of CD values is 0.2 ~ 0.025 / zm. However, if the 20 samples detected in Figure 4 are treated with the oxygen / nitrogen / argon plasma disclosed in the present invention, and after wet etching, the AEI-TAG (KMS-3 00) is used to detect the AEI-TAG ( 025〜0. 1 After Etching Inspection-Target) CD value, the results are shown in Figure 6, showing that the CD value difference between the 20 samples is not large, and the interval of the CD value distribution is significantly limited to 0. 025 ~ 0. 1 Between / zm, it is confirmed that the critical dimension in the manufacturing process can be effectively controlled after using the plasma treatment disclosed in the present invention. See Figure 7 again, remove the photoresist pattern, and then test the mask obtained by the above detection equipment. The results show that the CD values of AS I-TAG (After Striping Inspection-Target) among the 20 samples are evenly distributed. Between ± 25nm.

C: \ ProgramFiles \ Patent \ 0503-3881-E.ptd Page 9 V. Description of the Invention (7)-The above embodiment is all 2/4, AA φ ® ^ Β / V 4 The same plasma processing conditions are used in the manufacturing process. However, for the mask process Λ _ and 8 ^ even after the renewal to less than 0.18 heart, it is necessary to control the two of each mask more carefully. Operation: Therefore, in the production application, line width 0 25 " m and ο…… the price t &1; the mask is kept in the development step of the two-dimensional mask process, after the completion ^ each of them is tested individually in order The photoresist pattern located on the chrome film, and then the data stored in the computer f and the storage pattern determine the plasma processing conditions of each photoresist pattern, and then oxygen / nitrogen / blunt gas (5 / 5〇 / 2〇sccm ~ The formed Denso gas is individually processed for 25 to 40 seconds at a pressure of 10 to 3010, a DC bias of 60 to 90V, and an energy of 30 to 40W. Controlled two-bit mask. As shown in Figure 8A, the designed pattern is transferred to the photoresist pattern on the chrome film by the lithography program, and then the detector (KMS_3 〇) ADI-TAG CD values (Y-axis) of 5 samples are individually detected. The Φ8Α chart shows that the ADI-TAG CD values of 5 samples are distributed between 0.6 and 0.7 m. Then, according to each The CD value measured by a sample is automatically determined by the computer. The optimal plasma treatment conditions for each sample are processed individually. These five samples are treated individually under the oxygen / nitrogen / argon plasma treatment conditions. The plasma-treated mask is used as an etching mask. Wet etching is used to remove the exposed chromium film, and the pattern is transferred to the chromium film. The AEI-TAG CD value of the five samples is detected by the above-mentioned detector. Figure 8B shows that the difference in the CD values of the five samples is reduced, and the distribution range is reduced to between 0. 0 5 and 0. 0 7 // m. After removing the photoresist pattern on the chromium film, it is detected by the above-mentioned detector. The ASI-TAG CD values of these 5 samples are shown in Figure 8C. 'The CD value distribution range of these 5 samples is 20nm, which is controlled by

C: \ Program Files \ Patent \ 0503-3881-E.ptd page 10 V. Description of the invention (8) The difference in CD value is smaller than the above-mentioned method of uniformly using the same plasma processing conditions. Therefore, this method can be used to make a two-dimensional mask suitable for small line width. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Within the scope, the patent protection scope of the present invention shall be determined by the scope of the appended patent application scope.

C: \ Program Files \ Patent \ 0503_3881-E.ptd page 11

Claims (1)

6. Scope of Patent Application 1. A method for manufacturing a two-dimensional mask capable of controlling a critical size, the steps include: providing a quartz substrate covered with a chromium film; and forming a photoresist pattern on the chromium film by a lithography process; Applying a plasma consisting of an oxygen / nitrogen / blunt gas mixture to the photoresist pattern; using the plasma-treated photoresist pattern as a mask to wet-etch the chromium film; and removing the photoresist pattern, Obtain a two-dimensional veil of critical size. 2. The method as described in item 1 of the scope of patent application, wherein the ratio of oxygen / nitrogen / passive gas in the plasma mixed gas is 5/50 / 20sccm ~ 10/50 / 40sccm. 3. The method according to item 2 of the scope of patent application, wherein the inert gas is argon. 4. The method as described in item 2 of the patent application scope, wherein the inert gas is helium. 5. The method described in item 2 of the scope of patent application, wherein the pressure of the mixed gas during the plasma processing is 10 to 30 mtorr, the DC bias is 60 to 90 V, and the energy is 30 to 40 W. 6. The method according to item 5 of the scope of patent application, wherein the plasma processing time is 25 to 40 seconds. 7. A method for manufacturing a two-dimensional mask capable of controlling critical dimensions, the steps include: C: \ ProgramFiles \ Patent \ 0503-3881-E.ptd page 12 々 The scope of the patent application provides a plurality of quartz substrates covered with a chromium film; a photoresist pattern is formed on these chromium molds by a lithography process; Detect the CD values of the photoresist patterns individually; determine the oxygen / nitrogen / passivation plasma treatment conditions required for each photoresist pattern according to the individual CD values obtained by detecting the photoresist patterns, and use the Plasma treatment conditions apply a treatment to the photoresist pattern; use the plasma-treated photoresist pattern as a mask to wet etch the chrome film; and remove the photoresist pattern to obtain a second dimension where the critical size is controlled The curtain. 8. The method according to item 7 of the scope of patent application, wherein the oxygen / nitrogen / passive gas ratio in the plasma mixed gas is 5/5 0/2 0 sccm ~ 1 0/5 0/4 0 sccm ° 9 The method as described in claim 8 of the scope of patent application, wherein the inert gas is argon. 10. The method according to item 8 of the scope of the patent application, wherein the gas is helium. 1 1. The method according to item 8 of the scope of patent application, wherein the pressure during the plasma processing is 10 to 30 mtorr, the DC bias voltage is 60 to 90 V, and the energy is 30 to 40 W. 1 2. The method as described in item 11 of the scope of patent application, wherein the plasma treatment time is 25 to 40 seconds. C: \ ProgramFiles \ Patent \ 0503-3881-E.ptd page 13