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KR-102960766-B1 - Substrate processing method and substrate processing device

KR102960766B1KR 102960766 B1KR102960766 B1KR 102960766B1KR-102960766-B1

Abstract

A process is performed by supplying a treatment gas containing a halogen-containing gas and a basic gas to a substrate having a concave portion formed therein, wherein the sidewall is formed by a silicon film and the inner wall is formed by a germanium-containing film, thereby altering the surface of the silicon film to produce a reaction product; a second process is performed by removing the reaction product to expand the width of the concave portion; a process of performing a cycle consisting of the first process and the second process multiple times; and a process in which the first process of the first cycle is performed under a first treatment condition, and the first process of the subsequent cycle is performed under a second treatment condition different from the first treatment condition.

Inventors

  • 신도 나오키
  • 마츠나가 주니치로

Assignees

  • 도쿄엘렉트론가부시키가이샤

Dates

Publication Date
20260507
Application Date
20230913
Priority Date
20220921

Claims (15)

  1. A first process of supplying a treatment gas containing a halogen-containing gas and a basic gas to a substrate having a concave portion formed therein, wherein the sidewall is formed by a silicon film and the inner wall is formed by a germanium-containing film, thereby altering the surface of the silicon film to produce a reaction product, and A second process of removing the reaction product to expand the width of the concave portion, and A process of performing a cycle consisting of the above-mentioned first process and the above-mentioned second process multiple times, and A process in which the first process of the above-mentioned cycle is performed first under a first processing condition, and the first process of the above-mentioned cycle is performed subsequently under a second processing condition different from the first processing condition. A substrate processing method including
  2. A substrate treatment method according to claim 1, wherein the first treatment condition and the second treatment condition differ in at least one of the ratio of the basic gas to the halogen-containing gas in the treatment gas, or the supply time of the treatment gas.
  3. A substrate treatment method according to paragraph 2, wherein the ratio of the basic gas to the halogen-containing gas is smaller in the first treatment condition than in the second treatment condition, or the supply time of the treatment gas is shorter in the first treatment condition than in the second treatment condition.
  4. A substrate treatment method according to paragraph 2, wherein the ratio of the basic gas to the halogen-containing gas is greater in the first treatment condition than in the second treatment condition, or the supply time of the treatment gas is longer in the first treatment condition than in the second treatment condition.
  5. In paragraph 3 or 4, the concave portion is formed in multiple stages in the thickness direction of the substrate, and A substrate processing method in which a plurality of concave portions are each opened in a direction intersecting the thickness direction.
  6. A substrate treatment method according to paragraph 2, wherein the halogen-containing gas is a first fluorine-containing gas and the basic gas is ammonia gas.
  7. A substrate treatment method according to claim 6, wherein the first fluorine-containing gas is a fluorine gas.
  8. A substrate treatment method according to claim 1, wherein the germanium-containing film is a silicon germanium film.
  9. A substrate treatment method according to paragraph 2, wherein in either of the first treatment condition and the second treatment condition, the ratio of the basic gas to the halogen-containing gas is less than 0.014.
  10. A substrate processing method according to paragraph 2, wherein, in the first processing condition and the second processing condition, the supply time of the processing gas is 10 seconds to 15 seconds.
  11. A substrate processing method according to claim 10, wherein the first process comprises a process of supplying the processing gas into the processing vessel while the pressure inside the processing vessel containing the substrate is greater than 200 Pa.
  12. In paragraph 1, the first process is, A first supply process in which the supply of the above-mentioned halogen-containing gas to the above-mentioned substrate and the supply of the above-mentioned basic gas to the above-mentioned substrate are carried out in parallel, and A second supply process that supplies only one of the halogen-containing gas and the basic gas to the substrate after the first supply process above. A substrate processing method comprising
  13. In Clause 12, the above halogen-containing gas is, A first fluorine-containing gas supplied to the substrate in the first supply process above, and It consists of a second fluorine-containing gas supplied to the substrate in the second supply process above, and A substrate processing method in which the first fluorine-containing gas and the second fluorine-containing gas are of different types.
  14. In paragraph 13, the above-mentioned first fluorine-containing gas is a fluorine gas, and A substrate treatment method in which the second fluorine-containing gas is hydrogen fluoride gas.
  15. A first treatment unit that supplies a treatment gas including a halogen-containing gas and a basic gas to alter the surface of said silicon film in a substrate in which a concave portion is formed, wherein the sidewall is formed by a silicon film and the inner wall is formed by a germanium-containing film, in order to produce a reaction product; A second processing unit that removes the reaction product to expand the width of the concave portion, and A control unit that outputs a control signal to perform a cycle comprising processing by the first processing unit and processing by the second processing unit multiple times, wherein the processing by the first processing unit of the first cycle is performed under a first processing condition, and the processing by the first processing unit of the subsequent cycle is performed under a second processing condition different from the first processing condition. A substrate processing device including

Description

Substrate processing method and substrate processing device The present disclosure relates to a substrate processing method and a substrate processing apparatus. In manufacturing a semiconductor device, there are cases where the Si film among the Si film and SiGe film formed on the surface of a semiconductor wafer (hereinafter referred to as the wafer) which is a substrate is selectively etched. For example, Patent Document 1 describes using F₂ gas and NH₃ gas as etching gases and performing the selective etching by setting the ratio of NH₃ gas to the etching gas to a predetermined value. FIG. 1 is a cross-sectional side view of a wafer on which processing is performed, which is an embodiment of the present disclosure. FIG. 2 is an explanatory diagram illustrating the change in the concave portion before and after etching. Figure 3 is a cross-sectional side view of the wafer after etching. Figure 4 is an explanatory diagram illustrating the change in the Si film forming the concave portion. Figure 5 is an explanatory diagram illustrating the change in the Si film forming the concave portion. Figure 6 is an explanatory diagram illustrating the change in the Si film forming the above-mentioned concave portion. Figure 7 is an explanatory diagram illustrating the change in the concave portion during etching. Figure 8 is an explanatory diagram illustrating the appearance of the above-mentioned concave portion becoming a rectangular shape. FIG. 9 is an explanatory diagram illustrating the appearance of the above-mentioned concave portion becoming round in shape. FIG. 10 is a flowchart illustrating the processing of the present embodiment. FIG. 11 is a plan view illustrating one embodiment of a substrate processing apparatus for performing the above processing. FIG. 12 is a cross-sectional side view showing an example of a processing module provided in the substrate processing device. Figure 13 is a graph showing the results of the evaluation test. Figure 14 is a graph showing the results of an evaluation test. Figure 15 is a graph showing the results of the evaluation test. An embodiment of the substrate processing method of the present disclosure is described. FIG. 1 is a cross-sectional side view of the surface of a wafer (W) which is a substrate, showing the state before the etching treatment according to the present embodiment is performed. A lower layer film (11) is formed on the wafer (W). On the lower layer film (11), a SiGe (silicon germanium) film (12) and a Si (silicon) film (13) are alternately and repeatedly stacked. By forming such a repeating structure, the SiGe film (12) and the Si film (13) are each formed in multiple stages in the thickness direction of the wafer (W). The thickness direction of the wafer (W) is described as the longitudinal direction. The Si film (13) is formed, for example, by epitaxial growth. A mask film (14) is laminated on the uppermost Si film (13) of the above repeating structure to prevent etching from above the Si film (13). A concave portion extending in the vertical direction is formed from the mask film (14) to the upper side of the lower film (11). This concave portion is a groove (15) extending in the front-to-back direction of the surface of FIG. 1. The groove (15) is opened on the upper surface of the mask film (14). The side walls of the groove (15) are formed by the surface portions of the mask film (14), the Si film (13), and the lower film (11), respectively, and are positioned spaced apart from the side walls of the groove (15) for each SiGe film (12). Accordingly, when viewed in a vertical cross-section, the left wall of the groove (15) has multiple left-facing concave sections formed at intervals from each other, and the right wall of the groove (15) has multiple right-facing concave sections formed at intervals from each other. These left and right-facing concave sections are respectively referred to as concave sections (16). Accordingly, the concave sections (16) are formed at multiple intervals in the thickness direction of the wafer (W), and are formed to be open in directions intersecting this thickness direction. The groove (15) and the concave portion (16) are formed to form a left-right symmetrical structure, and the vertical width of each concave portion (16) is the same or approximately the same. Subsequently, the upper concave portion (16), the lower concave portion (16), and the concave portion (16) between the upper and lower sides in the Si film (13) may be described as the top concave portion (16), the bottom concave portion (16), and the middle concave portion (16), respectively. In addition, the height of the stack formed by the SiGe film (12) and the Si film (13) (= height from the upper surface of the lower layer film (11) to the bottom of the mask film (14)) is, for example, 4 μm. FIG. 2 shows an enlarged view of one of the concave portions (16). The upper side corresponds to the state before etching shown in FIG. 1, and the lower side i