JP2009246226A - Method and apparatus for forming hole, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a hole capable of forming a larger number of holes by one-time light exposure. <P>SOLUTION: A circular cylinder is formed on a silicon oxide film 51 in the other region surrounding one region among a plurality of regions which become formation positions for holes 511 and 512. In particular, the circular cylinder is formed on the silicon oxide film 51 in the other region surrounding one region in planar view among four or more regions. Next, a silicon nitride film is formed on the silicon oxide film 51 and the circular cylinder. The silicon nitride film is etched back. By etching back, a sidewall 541 surrounding the circular cylinder is formed. The circular cylinder is etched. At last, the silicon oxide film 51 is etched using the sidewall 541 as a mask. Thereby, the hole 512 corresponding to one region and the hole 511 corresponding to the other region are formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hole forming method, a hole forming apparatus, and a program for forming holes in a plurality of regions of a film on a substrate.

In the manufacturing process of a semiconductor device, a large number of contact holes (hereinafter referred to as holes) for lead electrodes are formed in a silicon oxide film on a substrate. These holes are formed through a photolithography process, an etching process, and a resist stripping process. In recent years, high-density hole formation is required, but the resolution of the exposure apparatus in the photolithography process is also limited. Conventionally, a technique has been proposed in which holes are first formed in half and then exposed again to form holes in the gaps of holes that have already been formed (see, for example, Patent Document 1).
JP 2006-261307 A

  However, the conventional technique requires two exposures, and it is also necessary to shrink holes in an atmosphere containing oxygen radicals. Furthermore, in the second exposure, it is necessary to improve the position accuracy.

  The present invention has been made in view of such circumstances, and an object of the present invention is to select one region surrounded by a plurality of other regions and form protrusions in other regions other than the one region. Accordingly, it is an object of the present invention to provide a hole forming method, a hole forming apparatus, and a program capable of forming more holes in one exposure.

  The hole forming method according to the present invention is a hole forming method in which holes are formed in a plurality of regions of a film on a substrate, and a plurality of other regions surrounding one region of the plurality of regions serving as hole formation positions are formed on the film. Forming a protrusion on the film, forming an auxiliary film on the film and the protrusion, forming a sidewall surrounding the protrusion by etch back, etching the protrusion, A step of etching the plurality of other regions and the film in one region using the sidewall as a mask.

  In the hole forming method according to the present invention, in the step of forming the protrusion, the protrusion is formed on a film in a plurality of other regions of three or more surrounding one region out of the plurality of regions of four or more serving as hole formation positions. It is characterized by forming an object.

  In the hole forming method according to the present invention, the step of forming the protrusion surrounds one region among the step of forming the first film on the film and the four or more regions serving as the hole formation positions. A step of forming a photoresist on the first film in a plurality of other regions of three or more, and a step of etching the first film using the photoresist as a mask to form a protrusion. .

  A hole forming apparatus according to the present invention is a hole forming apparatus that forms holes in a plurality of regions of a film on a substrate, and is formed on a plurality of other regions surrounding one region among the plurality of regions serving as hole formation positions. And a transport means for transporting the substrate on which the auxiliary film is formed on the film to an etching apparatus, and the controller of the etching apparatus has a sidewall surrounding the protrusion by etch back. Forming means; etching means for etching the protrusion; and means for etching the plurality of other regions and the film in one region using the sidewall as a mask.

  The program according to the present invention is a program used in a computer for controlling an etching apparatus that forms holes in a plurality of regions of a film on a substrate. The computer further includes a plurality of other regions among a plurality of regions serving as hole formation positions. Determining whether or not the protrusion formed on the film in the other region excluding the one region surrounded by the substrate and the substrate on which the auxiliary film is formed on the film are transported, When it is determined that the substrate has been transported, a step of forming a sidewall surrounding the protrusion by etching back, a step of etching the protrusion, and the plurality of other regions and the one of the other regions using the sidewall as a mask. Etching the film in a region.

  In the present invention, the protrusion is formed on the film of the plurality of other regions surrounding the one region among the plurality of regions serving as the hole forming positions. Specifically, a protrusion is formed on the film of three or more other regions surrounding one region among the four or more regions. Next, an auxiliary film is formed on the film and the protrusion. The auxiliary film is etched back. By this etch back, a sidewall surrounding the projection is formed. The cylinder surrounded by the sidewall is etched. Finally, a plurality of other regions and the film in one region are etched using the sidewall as a mask.

  In the present invention, a protrusion is formed on the film of the other region excluding one region surrounded by the other plurality of regions among the plurality of regions serving as hole formation positions, and the side based on the protrusion Form a wall. Then, a plurality of other regions and one region of the film are etched using the sidewall as a mask. Accordingly, a film corresponding to another region is etched by one sidewall. Further, the film corresponding to one region surrounded by the plurality of sidewalls is also etched. As described above, the formation of the side wall based on the formation of the protrusions related to the other region enables high-density and shorter at the hole forming position corresponding to one region as well as the other region by only one exposure. The present invention has excellent effects, such as being able to form holes in the process.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic plan view showing an outline of the hole forming apparatus 1. The hole forming apparatus 1 includes a first carry-in chamber 401, a first film formation chamber 61, a spin coater 63, a first vacuum transfer robot 41 (hereinafter referred to as a first robot 41), a second carry-in chamber 402, a second film formation chamber 62, The first processing chamber 501, the exposure apparatus 70, the etching apparatus 10, the second processing chamber 502, a second vacuum transfer robot (hereinafter referred to as second robot 42), a discharge chamber 403, a vacuum gate G, and the like are configured. The The substrate W is a silicon wafer and is transferred into the hole forming apparatus 1. In the following description, the substrate W is replaced with the wafer W.

  The first carry-in chamber 401, the first film forming chamber 61, the spin coater 63, the first processing chamber 501, and the second carry-in chamber 402 are provided around the first robot 41, and each device and chamber are sealed. It is connected through a vacuum gate G having a property. Similarly, the second film forming chamber 62, the exposure apparatus 70, the second carry-in chamber 402, the etching apparatus 10, the second processing chamber 502, and the carry-out chamber 403 are provided around the second robot 42, and The apparatus and the chamber are connected through a vacuum gate G having a sealing property. The first film formation chamber 61, the second film formation chamber 62, the etching apparatus 10, the exposure apparatus 70, and the like are connected to each other via a communication network N, and transmit and receive information using a predetermined protocol. In the present embodiment, the exposure apparatus 70, the first film formation chamber 61, the etching apparatus 10 and the like are shown as an integral connection, but this is only an example and is not limited to the configuration shown in FIG. .

  FIG. 2 is an explanatory view showing the formation positions of holes. FIG. 2A shows a region where a hole is to be formed. Regions C1 and C2 indicated by white circles correspond to hole formation positions. FIG. 2B shows a pattern M1 formed on the photomask 70M. The photomask 70M is formed of a translucent quartz substrate, and the pattern M1 is formed on the photomask 70M with chromium or the like. Specifically, the areas corresponding to the areas C1, C1,... Excluding the area (one area) C2 surrounded by the four areas (other areas) C1, C1, C1, C1 shown in FIG. Patterns M1, M1,... Are formed on the photomask 70M. In this example, four other regions C1, C1, C1, and C1 are arranged in a lattice pattern. In other words, other regions C1, C1, C1, and C1 having the center are arranged on each vertex of the square in plan view. A region located in the center of the four other regions C1, C1, C1, and C1 will be described as one region C2.

  Patterns M1, M1,... Shown by hatched circles are formed on the photomask 70M as shown in FIG. On the other hand, M2 indicated by a dotted circle is illustrated for easy understanding. M2 indicated by a dotted circle is a hole formation region, but corresponds to one region C2, and thus no pattern is formed on the photomask 70M. In this embodiment, an example in which a positive type is used in the exposure apparatus 70 will be described, but it is needless to say that a negative type may be used.

3 to 7 are process diagrams showing a hole forming process. The hole forming process will be described in the order of (a) to (h) in FIGS. The wafer W is transferred to the first loading chamber 401. The first robot 41 transfers the wafer W transferred to the first carry-in chamber 401 to the first film forming chamber 61. In the first film forming chamber 61, the film 51 is formed on the wafer W by CVD (Chemical Vapor Deposition), ALD (Atomic Layer Deposition), sputtering, or the like. Hereinafter, an example in which a silicon oxide film (SiO ₂ ) 51 is formed on the wafer W by CVD will be described. The first film forming chamber 61 grows a silicon oxide film 51 in which holes are formed on the wafer W by reacting oxygen and silicon in a steam atmosphere of about 900 ° C. Note that another film may be formed between the wafer W and the silicon oxide film 51.

In the first film formation chamber 61, after the silicon oxide film 51 is formed, the first film 52 is formed on the silicon oxide film 51. The first film 52 is, for example, an amorphous silicon film, a polysilicon film, a silicon nitride film (Si ₃ N ₄ ), or the like. Hereinafter, the first film 52 will be described as being an amorphous silicon film 52, and the wafer W and the film formed on the wafer W are collectively referred to as a sample S. The first film formation chamber 61 forms an amorphous silicon film 52 on the silicon oxide film 51 by supplying SiH ₄ gas and heating the wafer W. Thereafter, the first film forming chamber 61 ends the film forming process.

  When the formation of the silicon oxide film 51 and the amorphous silicon film 52 is completed, the first robot 41 takes out the sample S from the first film formation chamber 61 and transports the sample S to the spin coater 63. In the spin coater 63, a photoresist solution is dropped on the amorphous silicon film 52. The spin coater 63 rotates the sample S at a high speed and applies a photoresist thin film 53 having a uniform thickness. When the application of the photoresist thin film 53 is completed, the first robot 41 takes out the sample S from the spin coater 63 and conveys the taken out sample S to the second carry-in chamber 402.

  When the second robot 42 determines that the sample S has been transferred to the second carry-in chamber 402, the second robot 42 transfers the sample S to the exposure apparatus 70. The exposure apparatus 70 is equipped with a photomask 70M on which the patterns M1, M1,... Described in FIG. FIG. 3A is a process diagram showing an exposure process. 3 to 7, the upper diagram is a plan view of the photomask 70M or the sample S, and the lower diagram is a schematic cross-sectional view of the photomask 70M or the sample S indicated by the line III-III in FIG. 3. . The description of the line III-III is omitted in FIG. After aligning the photomask 70M and the sample S, the exposure apparatus 70 irradiates the photoresist thin film 53 with laser light through the photomask 70M.

  As shown in FIG. 3A, the laser light is irradiated on the region excluding the region where the pattern M1 is formed. After the exposure process for the sample S, the second robot 42 takes out the sample S from the exposure apparatus 70 and transports the sample S to the second carry-in chamber 402 again for the development process. The first robot 41 transfers the sample S transferred to the second carry-in chamber 402 to the first processing chamber 501. FIG. 3B is a process diagram showing a process of removing the photoresist thin film 53. The first processing chamber 501 is provided with a spin developer. In the first processing chamber 501, the developer is applied onto the photoresist thin film 53, the exposed photoresist thin film 53 is dissolved, and the remaining photoresist thin film 531 on the region corresponding to the other pattern M1 is not dissolved. Remains. As shown in FIG. 3B, a remaining photoresist thin film 531 protrudes from the amorphous silicon film 52 in a region corresponding to the pattern M1.

  After the formation of the remaining photoresist thin film 531, the first robot 41 takes out the sample S from the first processing chamber 501 through post-baking or the like, and transports the taken out sample S to the second carry-in chamber 402. When the second robot 42 determines that the sample S has been transferred to the second carry-in chamber 402, the second robot 42 then transfers the sample S to the etching apparatus 10. In the etching apparatus 10, each film including the amorphous silicon film 52 and the like is etched. Although either a wet type or a dry type is used for the etching, in the present embodiment, a mode in which a plasma processing apparatus that performs RIE (Reactive Ion Etching) processing on the sample S will be described. Hereinafter, the etching apparatus 10 will be described as the plasma processing apparatus 10.

  FIG. 8 is a schematic cross-sectional view showing the configuration of the plasma processing apparatus 10. The plasma processing apparatus 10 includes a chamber 11, a CPU (central processing unit), a control unit 210 including a memory storing a program for executing various software processes, a LAN (local area network) card connected to the communication network N, and the like The communication unit 211 and the like are included.

  The plasma processing apparatus 10 includes, for example, a chamber 11 that houses a sample S having a diameter of 300 nm, and a cylindrical susceptor 12 on which the sample S is placed is disposed in the chamber 11. In the plasma processing apparatus 10, the side exhaust path 13 that functions as a flow path for discharging the gas above the susceptor 12 to the outside of the chamber 11 is formed by the inner wall of the chamber 11 and the side surface of the susceptor 12. A baffle plate 14 is disposed in the middle of the side exhaust passage 13.

  The baffle plate 14 is a plate-like member having a large number of holes, and functions as a partition plate that partitions the chamber 11 into an upper part and a lower part. A susceptor 12 or the like on which the sample S is placed is disposed on the upper portion of the chamber 11 partitioned by the baffle plate 14 to generate plasma described later. Hereinafter, the upper part of the chamber 11 is referred to as a “reaction chamber”. Further, a roughing exhaust pipe 15 and a main exhaust pipe 16 for discharging the gas in the chamber 11 are opened at the lower part of the chamber 11 (hereinafter referred to as “exhaust chamber (manifold)”). A DP (Dry Pump) (not shown) is connected to the roughing exhaust pipe 15, and a TMP (Turbo Molecular Pump) (not shown) is connected to the exhaust pipe 16. Further, the baffle plate 14 captures or reflects ions or radicals generated in a processing space S <b> 1 (to be described later) of the reaction chamber 17 to prevent leakage to these manifolds 18.

  The roughing exhaust pipe 15, the main exhaust pipe 16, DP, TMP, and the like constitute an exhaust device, and the roughing exhaust pipe 15 and the main exhaust pipe 16 pass the gas in the reaction chamber 17 to the outside of the chamber 11 through the manifold 18. Discharge. Specifically, the roughing exhaust pipe 15 depressurizes the inside of the chamber 11 from the atmospheric pressure to a low vacuum state, and the main exhaust pipe 16 cooperates with the roughing exhaust pipe 15 in the chamber 11 from the atmospheric pressure to a low vacuum state. The pressure is reduced to a high vacuum state (for example, 133 Pa (1 Torr or less)) which is a lower pressure. A lower high frequency power supply 20 is connected to the susceptor 12 via a matcher 22, and the lower high frequency power supply 20 supplies predetermined high frequency power to the susceptor 12. Thereby, the susceptor 12 functions as a lower electrode. The matching unit 22 reduces the reflection of the high frequency power from the susceptor 12 to maximize the supply efficiency of the high frequency power to the susceptor 12.

  A disc-shaped ESC electrode plate 23 made of a conductive film is disposed above the susceptor 12. A DC power supply 24 is electrically connected to the ESC electrode plate 23. The sample S is adsorbed and held on the upper surface of the susceptor 12 by a Coulomb force or a Johnson-Rahbek force generated by a DC voltage applied to the ESC electrode plate 23 from the DC power source 24. An annular focus ring 25 is disposed above the susceptor 12 so as to surround the sample S adsorbed and held on the upper surface of the susceptor 12. The focus ring 25 is exposed to a processing space S1 to be described later, and the plasma is focused toward the surface of the sample S in the processing space S1, thereby improving the efficiency of the RIE processing.

  Further, for example, an annular refrigerant chamber 26 extending in the circumferential direction is provided inside the susceptor 12. A refrigerant having a predetermined temperature, for example, cooling water or galden, is circulated and supplied from the chiller unit (not shown) to the refrigerant chamber 26 via a refrigerant pipe 27 and is adsorbed and held on the upper surface of the susceptor 12 by the temperature of the refrigerant. The processing temperature of the sample S is controlled.

  A plurality of heat transfer gas supply holes 28 are opened in a portion of the upper surface of the susceptor 12 where the sample S is adsorbed and held (hereinafter referred to as “adsorption surface”). The plurality of heat transfer gas supply holes 28 are connected to a heat transfer gas supply unit (not shown) via a heat transfer gas supply line 30, and the heat transfer gas supply unit transfers helium gas as the heat transfer gas. The gas is supplied to the gap between the adsorption surface and the back surface of the sample S through the hot gas supply hole 28. The helium gas supplied to the gap between the adsorption surface and the back surface of the sample S transfers the heat of the sample S to the susceptor 12.

  A plurality of pusher pins 33 as lift pins that can protrude from the upper surface of the susceptor 12 are arranged on the suction surface of the susceptor 12. These pusher pins 33 are connected via a motor (not shown) and a ball screw (not shown), and freely protrude from the suction surface due to the rotational motion of the motor converted into a linear motion by the ball screw. To do. When the sample S is sucked and held on the suction surface in order to perform the RIE process on the sample S, the pusher pin 33 is accommodated in the susceptor 12, and when the sample S subjected to the RIE process is carried out of the chamber 11, the pusher pin 33 is The sample S protrudes from the upper surface of the susceptor 12 and is lifted upward while being separated from the susceptor 12.

  A gas introduction shower head 34 (processing gas supply device) is disposed on the ceiling of the chamber 11 (reaction chamber 17) so as to face the susceptor 12. An upper high-frequency power source 36 is connected to the gas introduction shower head 34 via a matching unit 35, and the upper high-frequency power source 36 supplies predetermined high-frequency power to the gas introduction shower head 34. Functions as an electrode. The function of the matching unit 35 is the same as the function of the matching unit 22 described above.

The gas introduction shower head 34 has a ceiling electrode plate 38 having a large number of gas holes 37 and an electrode support 39 that detachably supports the ceiling electrode plate 38. A buffer chamber 29 is provided inside the electrode support 39, and a processing gas introduction pipe 41 is connected to the buffer chamber 29. The gas introduction shower head 34 supplies the processing gas supplied from the processing gas introduction pipe 41 to the buffer chamber 29 into the chamber 11 (reaction chamber 17) via the gas hole 37. The supplied processing gas is, for example, CF ₄ , C ₄ F ₈ , O ₂ , Ar, or the like.

  The side wall of the chamber 11 is provided with an inlet / outlet G1 for the sample S at a position corresponding to the height of the sample S lifted upward from the susceptor 12 by the pusher pin 33. The inlet / outlet G1 includes the inlet / outlet G1. A vacuum gate G that opens and closes G1 is attached. In the chamber 11 of the plasma processing apparatus 10, as described above, high frequency power is supplied to the susceptor 12 and the gas introduction shower head 34. Then, by applying high-frequency power to the processing space S1 between the susceptor 12 and the gas introduction shower head 34, the processing gas supplied from the gas introduction shower head 34 in the processing space S1 is changed to high-density plasma to generate ions or radicals. And the sample S is etched by ions or the like.

FIG. 4C is a process diagram showing an etching process of the amorphous silicon film 52. The plasma processing apparatus 10 supplies, for example, O ₂ gas and HBr gas from the gas introduction shower head 34 in the processing space S1. The plasma processing apparatus 10 converts these gases into plasma and etches the amorphous silicon film 52 using the remaining photoresist thin film 531 as a mask to form cylindrical projections 521, 521,. The diameter of the cylindrical projection 521 (hereinafter referred to as the cylinder 521) may be 40 nm, for example, and the height may be 80 nm, which is about twice the diameter. Further, the distance between the center of the cross section of the cylinder 521 and the center of the cross section of another cylinder 521 located on the top, bottom, left, and right in plan view may be 80 nm. In addition, the numerical value described above is an example to the last, and is not restricted to this.

  The sample S in which the cylinders 521 are formed in a lattice shape on the silicon oxide film 51 in plan view is taken out from the plasma processing apparatus 10 by the second robot 42 and transferred to the second processing chamber 502. FIG. 4D is a process diagram showing a dissolution process of the remaining photoresist thin film 531. In the second processing chamber 502, as shown in FIG. 4D, a process of removing the remaining photoresist thin film 531 remaining on the head of the cylinder 521 is performed. The second processing chamber 502 is provided with a wet stripping device, and strips the remaining photoresist thin film 531 on the cylinder 521 with a stripping solution. After the remaining photoresist thin film 531 is peeled off, the second robot 42 takes out the sample S from the second processing chamber 502 and transports it to the second film forming chamber 62.

FIG. 5E is a process diagram showing a process of forming the auxiliary film 54. In the second film formation chamber 62, an auxiliary film 54 is formed on the silicon oxide film 51 and the cylinder 521 as shown in FIG. For example, a silicon nitride film (Si ₃ N ₄ ) or a polysilicon film may be used as the auxiliary film 54. Hereinafter, an example in which the silicon nitride film 54 is used as the auxiliary film 54 will be described. In the second film formation chamber 62, a silicon nitride film 54 is formed on the silicon film 51 and the cylinder 521 by plasma CVD using a reactive gas (SiH ₄ , NH _3, and N ₂ ). After forming the silicon nitride film 54, the second robot 42 takes out the sample S from the second film forming chamber 62 and transports the sample S to the plasma processing apparatus 10.

FIG. 5F is a process diagram showing an etch-back process. The plasma processing apparatus 10 supplies a processing gas from the processing gas introduction pipe 41 </ b> A, etches back the silicon nitride film 54, and forms a side wall 541 having a donut shape in plan view around the cylinder 521. Examples of the processing gas include CF ₄ gas, CHF ₃ gas, Ar gas, O ₂ gas, CH ₂ F ₂ gas, and F ₂ gas. The plasma processing apparatus 10 converts the processing gas into plasma and etches back the silicon nitride film 54 by anisotropic dry etching. As shown in FIG. 5 (e), the shoulder portion in the cross-sectional view of the cylinder 521, that is, the silicon nitride film 54 near the 2 o'clock position and the 10 o'clock position is thicker than the other portions. When etching is performed until the silicon nitride film 54 disappears, the sidewalls 541 remain as shown in FIG. Various controls including the etch back process are executed according to programs stored in the control unit 210.

FIG. 6G is a process diagram showing an etching process of the cylinder 521. The plasma processing apparatus 10 supplies a processing gas from the gas introduction shower head 34 and etches the column 521 made of amorphous silicon except for the sidewalls 541. Specifically, the plasma processing apparatus 10 supplies, for example, O ₂ gas and HBr gas from the gas introduction shower head 34. The plasma processing apparatus 10 converts these gases into plasma and etches the cylinders 521, 521,.

As a result, a large number of sidewalls 541 remain in a lattice shape on the silicon oxide film 51. FIG. 6H is a process diagram showing an etching process of the silicon oxide film 51. The plasma processing apparatus 10 supplies a processing gas from the gas introduction shower head 34 and etches the silicon oxide film 51 using the sidewall 541 as a mask to form holes 511 and 512. Specifically, the plasma processing apparatus 10 supplies, for example, Ar gas and C ₄ F ₈ gas from the gas introduction shower head 34. The plasma processing apparatus 10 converts these gases into plasma and etches the silicon oxide film 51 using the sidewalls 541 as a mask. As a result, a hole 511 is formed in the other region C1 surrounded by the inner periphery of the side wall 541 that is annular in plan view. At the same time, a hole 512 is formed in one region C2 surrounded by the outer periphery of the four sidewalls 541, 541, 541, 541.

FIG. 7I is a process diagram showing an etching process of the sidewall 541. The plasma processing apparatus 10 supplies a processing gas from the gas introduction shower head 34 and etches the sidewall 541 made of silicon nitride. Specifically, the plasma processing apparatus 10 supplies, for example, CF ₄ gas, CHF ₃ gas, Ar gas, O ₂ gas, CH ₂ F ₂ gas, and F ₂ gas from the gas introduction shower head 34. The plasma processing apparatus 10 converts these gases into plasma and removes the side walls 541 on the silicon oxide film 51 by etching.

  As shown in FIG. 7I, a star-shaped hole 512 is formed at the center surrounded by the four lattice-shaped holes 511, 511, 511, and 511 indicated by white circles. The hole 512 corresponds to one region C2 shown in FIG. 2A, and the hole 511 corresponds to another region C1. Similarly, the hole 512 corresponds to the pattern M2 indicated by the dotted line in FIG. 2B, and the hole 511 corresponds to the pattern M1. In FIG. 7, the shape of the hole 512 is indicated by a star in order to facilitate the discrimination between the hole 511 and the hole 512, but it becomes substantially circular like the hole 511 by etching. In this way, the cylinder 521 having the center thereof is formed at a predetermined distance on the apex of the square in plan view. Then, etching is performed using a sidewall 541 formed around the cylinder 521 as a mask. As a result, a hole 511 corresponding to the other region C1 is formed in the cylindrical portion 521, and a hole 512 corresponding to one region C2 centered on the approximate center of the square is formed. By executing this process, holes can be formed at a high density exceeding the resolution by a single exposure.

Embodiment 2
The second embodiment relates to a different form of hole formation. In the first embodiment, cylinders 521, 521, 521, and 521 relating to four other regions are formed on the vertices of a square in plan view, and are surrounded by these cylinders 521, 521, 521, and 521 at a substantially central portion thereof. Although the hole 512 related to one region is formed, the present invention is not limited to this. You may make it form the cylinder 521 which concerns on at least 3 or more other area | regions so that the one area | region located in the approximate center part may be enclosed.

  FIG. 9 is an explanatory view schematically showing a process of forming the cylinder 521 in a triangular shape in plan view. FIG. 9A is an explanatory diagram showing the formation positions of holes. Around one region C2, there are three other regions C1, C1, C1 located within a predetermined distance range from the center of the one region C2. The other regions C1, C1, C1 are formed on the vertices of an equilateral triangle in plan view, and there is one region C2 surrounded by these at the substantially central portion. In the present embodiment, an example will be described in which another region C1 is arranged on the apex of an equilateral triangle, and one region C2 is present at substantially the center thereof. However, it is not necessarily strictly an equilateral triangle. There may be some deviation. Also, the one region C2 located at the substantially central portion does not need to be strictly at the center, and there may be some deviation. Similarly, the four other regions C1 described in the first embodiment do not have to be strictly on the vertices of a square in plan view, and may be slightly shifted. Further, the one region C2 in the first embodiment does not have to be strictly located at the center, and may be slightly shifted.

  FIG. 9B is an explanatory diagram showing an arrangement example of the pattern M1 formed on the photomask 70M. On the photomask 70M, three patterns M1, M1, and M1 corresponding to the other region C1 are formed to be similar to the other regions C1, C1, and C1. A pattern M2 indicated by a dotted line corresponding to one region C2 is not formed even though it is a hole forming position. FIG. 9C is a plan view showing a state after the etching process of the silicon oxide film 51. FIG. 9 (c) corresponds to FIG. 6 (h). For ease of explanation, description of the film-formed material other than the three points constituting the triangle is omitted. The sidewalls 541, 541, 541 are formed in a regular triangle shape in plan view.

  The silicon oxide film 51 is etched using the sidewall 541 as a mask to form a hole 511 surrounded by the inner periphery of one sidewall 541 and a hole 512 surrounded by the outer periphery of the three sidewalls 541, 541, 541. FIG. 9D is a plan view showing a state after the etching process of the sidewall 541. FIG. 9 (d) corresponds to FIG. 7 (i). Corresponding to other regions C1, C1, and C1, holes 511, 511, and 511 are formed on the vertices of a regular triangle. In addition, a hole 512 is formed at substantially the center of the three holes 511, 511, and 511 corresponding to one region C2.

  FIG. 10 is an explanatory view schematically showing a process of forming the cylinder 521 into a pentagonal shape in plan view. As described above, the total number of regions may be at least 4 or more, and as described below, the shape formed by the other regions C1 may be a pentagon or more. FIG. 10A is an explanatory diagram showing the hole formation position. Around one region C2, there are five other regions C1, C1, C1, C1, C1 located within a predetermined distance range from the center of the one region C2. The centers of the other regions C1, C1, C1, C1, and C1 are arranged on the apexes of a regular pentagon in plan view. One region C2 surrounded by these regions C1, C1, C1, C1, and C1 is present at a substantially central portion. Needless to say, there may be some deviation between the one region C2 and the other region C1.

  FIG. 10B is an explanatory diagram showing an arrangement example of the pattern M1 formed on the photomask 70M. On the photomask 70M, five patterns M1, M1, M1, M1, and M1 corresponding to other regions C1 are formed to have similar shapes to the other regions C1, C1, C1, C1, and C1. A pattern M2 indicated by a dotted line corresponding to one region C2 is not formed even though it is a hole forming position. FIG. 10C is a plan view showing a state after the etching process of the silicon oxide film 51. FIG. 10 (c) corresponds to FIG. 6 (h). In addition, in order to make explanation easy, description about the film-formed product other than the five points constituting the pentagon is omitted. The sidewalls 541, 541, 541, 541, 541 are formed in a pentagonal shape in plan view.

  The silicon oxide film 51 is etched using the sidewall 541 as a mask to form a hole 511 surrounded by the inner periphery of one sidewall 541 and a hole 512 surrounded by the outer periphery of the five sidewalls 541, 541, 541, 541, 541. Is done. FIG. 10D is a plan view showing a state after the etching process of the sidewall 541. FIG. 10 (d) corresponds to FIG. 7 (i). Corresponding to other regions C1, C1, C1, C1, and C1, holes 511, 511, 511, 511, and 511 are formed on the apexes of a regular pentagon in plan view. In addition, a hole 512 is formed at substantially the center of the five holes 511, 511, 511, 511, and 511 corresponding to one region C2.

  FIG. 11 is an explanatory view schematically showing a process of forming the column 521 in a parallelogram shape in plan view. FIG. 11A is an explanatory diagram showing the formation positions of holes. The centers of four other regions C1, C1, C1, and C1 are arranged on the apexes of the parallelogram in plan view. The center of one region C2 exists at the intersection of a line segment connecting a pair of other regions C1 and C1 and a line segment connecting a pair of other regions C1 and C1 intersecting the line segment. Needless to say, there may be some deviation between the one region C2 and the other region C1.

  FIG. 11B is an explanatory diagram showing an arrangement example of the pattern M1 formed on the photomask 70M. On the photomask 70M, four patterns M1, M1, M1, and M1 corresponding to other regions C1 are formed to have similar shapes to the other regions C1, C1, C1, and C1. A pattern M2 indicated by a dotted line corresponding to one region C2 is not formed even though it is a hole forming position. FIG. 11C is a plan view showing a state after the etching process of the silicon oxide film 51. FIG. 11 (c) corresponds to FIG. 6 (h). For ease of explanation, description of the film formation other than the four points constituting the parallelogram is omitted. The sidewalls 541, 541, 541, 541 are formed in a parallelogram shape in plan view.

  The silicon oxide film 51 is etched using the sidewall 541 as a mask to form a hole 511 surrounded by the inner periphery of one sidewall 541 and a hole 512 surrounded by the outer periphery of the four sidewalls 541, 541, 541, 541. . FIG. 11D is a plan view showing a state after the etching process of the sidewall 541. FIG. 11 (d) corresponds to FIG. 7 (i). The centers of the holes 511, 511, 511, 511 are formed on the apexes of the parallelogram in plan view corresponding to the other regions C1, C1, C1, C1. In addition, a hole 512 is formed at a substantially central portion of the four holes 511, 511, 511, and 511 corresponding to one region C2.

  The second embodiment is configured as described above, and the other configurations and operations are the same as those of the first embodiment. Therefore, corresponding parts are denoted by the same reference numerals, and detailed description thereof is omitted.

Embodiment 3
FIG. 12 is a schematic cross-sectional view showing the configuration of the plasma processing apparatus 10 according to the third embodiment. The control unit 210 includes a CPU 218, a RAM (Random Access Memory) 212, an input unit 213, a storage unit 215, and the like. The CPU 218 is connected to each hardware unit of the control unit 210 via the bus 217, and controls the plasma processing apparatus 10 according to a control program 215P stored in the storage unit 215. The input unit 213 includes operation buttons and the like, and inputs etching conditions including temperature, gas inflow amount, etching time, and the like. The CPU 218 stores the etching conditions input from the input unit 213 in the storage unit 215. The CPU 218 executes the control program 215P, and controls the plasma processing apparatus 10 according to the etching conditions stored in the storage unit 215.

  A program for operating the plasma processing apparatus 10 according to the first and second embodiments includes a portable recording medium 1A such as a CD-ROM in a recording medium reading device (not shown) as in the third embodiment. It can also be read and stored in the storage unit 215 or downloaded from another computer (not shown) connected via a communication network such as the Internet (not shown).

  FIG. 13 is a flowchart showing the procedure of the hole forming process. The CPU 218 determines whether or not the sample S (FIG. 5E) in which the silicon nitride film 54 is formed on the silicon oxide film 51 and the cylinder 521 has been transferred (step S121). Specifically, the CPU 218 determines whether or not the formation information of the silicon nitride film 54 transmitted from the second film formation chamber 62 connected via the communication unit 211 has been received. When the sample S is transferred after receiving the information on the formation of the silicon nitride film 54, the CPU 218 determines that the sample S is the sample S in which the silicon nitride film 54 is formed on the silicon oxide film 51 and the cylinder 521. Then, the processing after step S121 is executed.

  When the CPU 218 determines that the sample S having the silicon nitride film 54 formed on the silicon oxide film 51 and the cylinder 521 is not transported (NO in step S121), the above processing is repeated. On the other hand, when the CPU 218 determines that the sample S having the silicon nitride film 54 formed on the silicon oxide film 51 and the cylinder 521 has been transported (YES in step S121), the CPU 218 reads the etching conditions stored in the storage unit 215 and performs plasma processing. The side wall 541 is formed by controlling the apparatus 10 (step S122). The CPU 218 etches the cylinder 521 (step S123).

  Subsequently, the CPU 218 etches the silicon oxide film 51 using the sidewall 541 as a mask to form holes 511 and 512 (step S124). The CPU 218 finally etches the sidewall 541 (step S125). Note that the specific processing contents of steps S122 to S125 are as described in the first embodiment, and thus detailed description thereof is omitted.

  The third embodiment is configured as described above, and the other configurations and operations are the same as those of the first and second embodiments. Therefore, corresponding parts are denoted by the same reference numerals, and detailed description thereof is omitted. To do.

It is a typical top view which shows the outline | summary of a hole formation apparatus. It is explanatory drawing which shows the formation position of a hole. It is process drawing which shows the formation process of a hole. It is process drawing which shows the formation process of a hole. It is process drawing which shows the formation process of a hole. It is process drawing which shows the formation process of a hole. It is process drawing which shows the formation process of a hole. It is typical sectional drawing which shows the structure of a plasma processing apparatus. It is explanatory drawing which shows typically the process of forming a cylinder in triangular shape in planar view. It is explanatory drawing which shows typically the process of forming a cylinder in pentagon shape in planar view. It is explanatory drawing which shows typically the process of forming a cylinder in parallelogram shape in planar view. 6 is a schematic cross-sectional view showing a configuration of a plasma processing apparatus according to Embodiment 3. FIG. It is a flowchart which shows the procedure of a hole formation process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hole formation apparatus 1A Portable recording medium 10 Plasma processing apparatus 41 1st robot 42 2nd robot 51 Silicon oxide film 52 Amorphous silicon film 53 Photoresist thin film 54 Silicon nitride film 61 1st film-forming chamber 62 2nd film-forming chamber 63 Spin coater 70 Exposure apparatus 70M Photomask 210 Control unit 211 Communication unit 215 Storage unit 215P Control program 218 CPU
401 First loading chamber 402 Second loading chamber 403 Discharging chamber 501 First processing chamber 502 Second processing chamber 511, 512 hole 521 Cylinder 531 Residual photoresist thin film 541 Side wall C1, C2 region G Vacuum gate M1 Pattern N Communication network S Sample W Wafer

Claims (5)

In a hole forming method for forming holes in a plurality of regions of a film on a substrate,
Forming a protrusion on a film of a plurality of other regions surrounding one region of the plurality of regions serving as hole formation positions;
Forming an auxiliary film on the film and the protrusion;
Forming a sidewall surrounding the protrusion by etch back;
Etching the protrusions;
Etching the plurality of other regions and the film in one region using the sidewall as a mask. The step of forming the protrusion includes
2. The hole forming method according to claim 1, wherein a protrusion is formed on a film of a plurality of other regions of three or more surrounding one region among the plurality of regions of four or more serving as hole formation positions. . The step of forming the protrusion includes
Forming a first film on the film;
A step of forming a photoresist on the first film in three or more other regions surrounding one region among four or more regions serving as hole formation positions;
The hole forming method according to claim 2, further comprising: etching the first film using the photoresist as a mask to form a protrusion. In a hole forming apparatus that forms holes in a plurality of regions of a film on a substrate,
A protrusion formed on a film in a plurality of other regions surrounding one region among a plurality of regions serving as hole formation positions, and a substrate on which an auxiliary film is formed on the film are transferred to an etching apparatus. A transport means,
The control unit of the etching apparatus
Means for forming sidewalls surrounding the protrusions by etch back;
Means for etching the protrusions;
And a means for etching the plurality of other regions and the film in one region using the sidewall as a mask. In a program used in a computer for controlling an etching apparatus that forms holes in a plurality of regions of a film on a substrate,
On the computer,
Protrusions formed on the film of the other region excluding one region surrounded by a plurality of other regions among the plurality of regions serving as hole formation positions, and an auxiliary film formed on the film Determining whether the substrate has been transported;
If it is determined that the substrate has been transported by the step, forming a sidewall that surrounds the protrusion by etch back; and
Etching the protrusions;
Etching the plurality of other regions and the film in one region using the sidewall as a mask.

Images