Method for manufacturing high aspect ratio glass via and glass via

Abstract

The application discloses a high-aspect-ratio glass via hole manufacturing method and a glass via hole. The method comprises the following steps: forming a photoresist mask on the surface of a substrate; performing a first etching step, using a plasma of a first gas filtered of charged particles to perform isotropic first etching on the substrate, and forming a first polymer layer on the inner wall of the forming via hole and the photoresist mask to protect the same; performing a second etching step, using a plasma of a second gas to perform anisotropic second etching on the first polymer layer on the bottom of the inner wall, exposing the underlying substrate to perform the first etching again; after completing the first etching step for a first preset number of times, performing a processing process on the forming via hole; and repeating the first etching step, the second etching step and the processing process until the via hole is formed on the substrate. The application can simplify the process, improve the selection ratio, improve the efficiency, and realize better side wall smoothness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor processing, in particular to a preparation method of a high aspect ratio glass via and a glass via prepared by using the method. BACKGROUND

[0002] At present, the dry etching process applied to glass via (TGV) processing is usually designed with the following steps:

[0003] 1) First, deposit a metal Al layer on the substrate as a hard mask layer for TGV etching;

[0004] 2) Cover photoresist on the Al layer, and expose the etching area on the Al layer by photolithography technology;

[0005] 3) Use Cl2 / BCL3 plasma etching to form an Al pattern on the exposed Al layer in the etching area;

[0006] 4) Use O2 to remove the photoresist;

[0007] 5) Take the Al pattern as a mask to perform TGV dry etching.

[0008] However, the actual process of the above TGV etching is relatively complex, the efficiency is low, and the cost is high. At the same time, using a metal mask may also cause byproduct pollution problems. Moreover, the existing TGV etching process usually adopts a non-periodic cycle etching mode (relative to a periodic cycle etching mode of the form of deposition-etching-deposition-etching repetition), which has relatively poor size uniformity and is difficult to meet the growing demand for larger aspect ratio and higher interconnection density. Therefore, it is necessary to study a process method that can significantly improve the above problems. SUMMARY

[0009] The present application aims to overcome the above problems existing in the prior art, and provides a preparation method of a high aspect ratio glass via and a glass via, so as to avoid using a metal mask, simplify the process, improve the efficiency, and improve the selection ratio of the photoresist mask, thereby facilitating the preparation of a glass via with higher aspect ratio and higher interconnection density.

[0010] To achieve the above-mentioned purpose, the technical solutions of the present application are as follows:

[0011] According to the first aspect of the present application, the present application provides a preparation method of a high aspect ratio glass via, comprising:

[0012] providing a substrate of glass material;

[0013] forming a plurality of photoresist masks on the surface of the substrate, and the first opening is formed between two adjacent photoresist masks;

[0014] performing an etching process to etch the surface of the substrate exposed in the first opening to form a via on the substrate;

[0015] wherein the etching process comprises a plurality of periodic cycle etching steps formed in sequence by a first etching step and a second etching step;

[0016] the first etching step uses plasma of a first gas filtered of charged particles to perform isotropic first etching of the substrate and to form a first polymer layer on the inner wall of the via under formation and the photoresist mask to protect the inner wall and the photoresist mask from the first etching;

[0017] the second etching step uses plasma of a second gas to perform anisotropic second etching of the first polymer layer on the bottom of the inner wall to form a second opening on the bottom and to expose the substrate for the first etching to be performed again through the second opening;

[0018] wherein after each first preset number of the first etching step in the periodic cycle etching steps is completed, a processing process is performed on the via under formation to improve the smoothness of the sidewall;

[0019] wherein the first gas is a first fluorocarbon-based gas with a fluorocarbon ratio greater than or equal to 1:3, and the second gas is a chlorine-based gas.

[0020] In some embodiments, the processing process comprises a deposition step and a third etching step; the deposition step comprises using plasma of a third gas to deposit a second polymer layer on the sidewall of the via under formation, and the third etching step comprises using plasma of a fourth gas to remove a partial thickness of the second polymer layer deposited on the sidewall and react with the substrate material present and exposed on the protrusion surface of the sidewall to remove at least part of the protrusion; wherein the third gas is a second fluorocarbon-based gas with a fluorocarbon ratio greater than or equal to 1:2, and the fourth gas is a fluorine-based gas.

[0021] In some embodiments, the first etching step is performed using a first pressure and a first bias power, the second etching step is performed using a second pressure and a second bias power, the deposition step is performed using a third pressure and a third bias power, and the third etching step is performed using a fourth pressure and a fourth bias power, the third pressure is greater than the first pressure, the first pressure is greater than the second pressure and the fourth pressure, the fourth bias power is greater than the second bias power, and the second bias power is greater than the first bias power and the third bias power.

[0022] In some embodiments, the first pressure is 100 mTorr to 1 Torr.

[0023] In some embodiments, the first bias power is 0 W.

[0024] In some embodiments, the second pressure is 10 mTorr to 100 mTorr.

[0025] In some embodiments, the second bias power is 50 W to 100 W.

[0026] In some embodiments, the third pressure is 1 Torr to 5 Torr.

[0027] In some embodiments, the third bias power is 0 W.

[0028] In some embodiments, the fourth pressure is 30 mTorr to 100 mTorr.

[0029] In some embodiments, the fourth bias power is 1000 W to 2000 W.

[0030] In some embodiments, the first fluorocarbon gas includes at least one of C4F8, C4F6, C5F8, CHF3, CH2F2.

[0031] In some embodiments, the chlorine-based gas includes BCl3.

[0032] In some embodiments, the second fluorocarbon gas includes at least one of C4F8, C4F6, C5F8, CH3F.

[0033] In some embodiments, the fluorine-based gas includes SF6.

[0034] In some embodiments, the first preset number of times is 1 or 2.

[0035] In some embodiments, the deposition step and the third etching step are repeatedly performed in sequence a second preset number of times each time the processing process is performed.

[0036] In some embodiments, the second preset number of times is 10 to 20.

[0037] In some embodiments, the etching process includes a first etching stage, a second etching stage, and a third etching stage connected in sequence, for forming a top portion, a middle portion, and a bottom portion of the via in sequence, respectively, and a fluorocarbon ratio of the first fluorocarbon gas used in the first etching stage, a fluorocarbon ratio of the first fluorocarbon gas used in the second etching stage, and a fluorocarbon ratio of the first fluorocarbon gas used in the third etching stage increase in sequence.

[0038] According to a second aspect of the present application, the embodiments of the present application also provide a glass via hole obtained by using the method for manufacturing a high aspect ratio glass via hole according to any one of the embodiments of the first aspect.

[0039] The embodiments of the present application can have / at least have the following advantages:

[0040] (1) By using the photoresist mask and the etching process including multiple periodic cyclic etching steps formed in sequence by the first etching step and the second etching step, performing isotropic first etching on the substrate using the plasma of the first gas from which charged particles are filtered, forming the first polymer layer on the inner wall of the forming via hole and the photoresist mask, and performing anisotropic second etching on the first polymer layer on the bottom of the inner wall using the plasma of the second gas to expose the underlying substrate for the first etching again, the selectivity of the photoresist mask can be significantly improved, so that the photoresist mask can replace the traditional metal hard mask, and a via hole (glass via hole) with a higher aspect ratio can be formed on the substrate, the etching uniformity and perpendicularity can be improved, the pollution problem when using the metal mask can be avoided, the process is simplified, and the efficiency is improved.

[0041] (2) By using the plasma of the first gas (the first fluorocarbon gas with a fluorocarbon ratio greater than or equal to 1:3) from which charged particles are filtered (i.e. using neutral particles in the plasma) to perform isotropic etching (first etching) on the substrate in each cycle, and turning off the bias power (the first bias power is 0W), the bombardment on the photoresist mask can be reduced, and the first polymer layer formed on the photoresist mask can be used to protect the photoresist mask during etching, so that the selectivity of the photoresist mask is significantly improved, and an etching structure with a certain depth is formed on the substrate, and then anisotropic etching (second etching) is performed on the substrate using the plasma of the second gas (chlorine-based gas) under a certain bias power (the second bias power is 50W-100W), a new opening (second opening) can be opened, so that the first etching can be performed again to continue etching downward, thereby eliminating the problem of difficult continuous etching downward caused by the isotropic etching in the previous step, and the first etching step and the second etching step can be repeatedly performed to finally form a high aspect ratio via hole (glass via hole) on the substrate, and a via hole structure with a higher aspect ratio and a higher interconnection density that cannot be achieved by conventional processes can be achieved.

[0042] (3) By using the first fluorocarbon gas with a carbon-fluorine ratio greater than or equal to 1:3 for the first etching, the high carbon-fluorine ratio can be used to enhance polymer formation, and a first polymer layer can be formed on the inner wall and the exposed surface of the photoresist mask during etching, thereby playing a dual role of etching and protection, so that not only the degree of lateral etching can be controlled, but also the deposition step, which is indispensable and separately arranged in the traditional periodic etching process, can be omitted. Therefore, only one set of process gas (first gas) system is needed to complete the etching and deposition processes that originally required two sets of process gas (etching gas + deposition gas) systems, greatly simplifying the process, improving efficiency, and reducing control difficulty.

[0043] (4) By using BCl3 (second gas) for the second etching, the inner wall bottom of the forming via can be directionally bombarded, the first polymer layer on the inner wall bottom can be removed, and the underlying substrate can be exposed for the first etching again. Meanwhile, BCl3 has the characteristic of not having a significant etching effect on the substrate (relative to conventional etching gases such as fluorine-containing gas), which can avoid damaging the formed etching morphology and prevent the problem of the upper size becoming larger with repeated etching, thereby ensuring etching uniformity and perpendicularity, and thus being more conducive to achieving higher aspect ratio and higher interconnection density of glass vias on the substrate, which is difficult to achieve in conventional processes.

[0044] (5) By performing a processing process on the forming via after completing the first etching step in the periodic etching step for a first predetermined number of times, and by using the plasma of the third gas (second fluorocarbon gas with a carbon-fluorine ratio greater than or equal to 1:2) to deposit a second polymer layer on the sidewall of the forming via, and then using the plasma of the fourth gas (fluorine-based gas) to remove part of the thickness of the second polymer layer deposited on the sidewall and react with the substrate material on the surface of the protruding part exposed on the sidewall to remove at least part of the protruding part, and repeating the process for a second predetermined number of times, the thickness uniformity of the polymer layer (first polymer layer, second polymer layer) on the sidewall can be adjusted, and the surface of the sidewall can be smoothed. By alternating between the deposition step and the third etching step in the periodic cycle and the etching process, the etching rate and the sidewall quality can be balanced, thereby achieving high etching rate and high etching precision (atomic level precision) of high aspect ratio glass vias, effectively improving the uniformity and roughness of the local polymer, solving the line width shift problem, achieving higher perpendicularity, and achieving better uniformity (uniform size at upper, middle, and lower positions of high aspect ratio glass vias), better sidewall smoothness, and improved device performance.

[0045] (6) When performing the deposition step, by using a second fluorocarbon gas (third gas) with a fluorocarbon ratio greater than or equal to 1:2, and under high pressure (third pressure) and with the bias power turned off (third bias power is 0 W), a second polymer layer is deposited on the sidewall, which makes the second polymer layer more likely to stay and accumulate on the sidewall surface at the recess between adjacent protrusions with relatively weak flow rate, preventing the continuous generation of lateral etching, while the sidewall surface at the end of the protrusion is rarely deposited; thus, when performing the third etching step by using a fluorine-based gas (fourth gas) plasma and under low pressure (fourth pressure) and a larger bias power (fourth bias power is 1000 W-2000 W), the flow rate of the etching gas is accelerated and directional, so that the etching is mainly concentrated on the end of the protrusion, thereby not only effectively removing the protrusion on the sidewall, but also effectively protecting the sidewall, which is conducive to maintaining the uniformity of the size.

[0046] (7) By subdividing the etching process into a first etching stage, a second etching stage and a third etching stage in sequence, which are used to form the top, middle and bottom of the via hole in sequence, and by increasing the fluorocarbon ratio of the first gas used in the first etching stage, the fluorocarbon ratio of the first gas used in the second etching stage and the fluorocarbon ratio of the first gas used in the third etching stage in sequence, the deposition can be enhanced by providing a higher fluorocarbon ratio during the continuous increase of the etching depth of the via hole, which can effectively inhibit the lateral etching of the sidewall bottom and eliminate the problem of bottom side digging, thereby further ensuring the size uniformity and perpendicularity in the depth direction. Therefore, by performing the etching process in stages, not only does it overcome the limitations of traditional single etching process that cannot achieve high-precision control, but it also provides a more precise and controllable etching solution for the manufacture of high-performance devices, effectively expanding the etching process window, and is conducive to realizing higher aspect ratio and higher interconnection density of glass via holes.

[0047] Other advantages of the present application will be described in the specific embodiments below. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 A flowchart of a method for manufacturing a high-aspect-ratio glass via hole according to a preferred embodiment of the present application.

[0049] Figure 2 A schematic diagram of a structure after forming a photoresist mask on a substrate according to a preferred embodiment of the present application.

[0050] Figure 3 A schematic diagram of a structure after forming a first intermediate via hole structure on a substrate according to a preferred embodiment of the present application.

[0051] Figure 4A structure schematic diagram after a first second opening is formed on the bottom of the first first intermediate via structure for a preferred embodiment of the present application.

[0052] Figure 5 A structure schematic diagram after a second first intermediate via structure is formed under the first second opening for a preferred embodiment of the present application.

[0053] Figure 6 A structure schematic diagram after a second polymer layer is formed on the sidewall of the first intermediate via structure and the photoresist mask for a preferred embodiment of the present application.

[0054] Figure 7 A structure schematic diagram after a second intermediate via structure is formed after the sidewall of the first intermediate via structure is processed for a preferred embodiment of the present application.

[0055] Figure 8 A structure schematic diagram after a second opening is continuously formed on the bottom of the second intermediate via structure for a preferred embodiment of the present application.

[0056] Figure 9 A structure schematic diagram after a first intermediate via structure is continuously formed under the second intermediate via structure for a preferred embodiment of the present application.

[0057] Figure 10 A structure schematic diagram after a via is formed for a preferred embodiment of the present application.

[0058] Figure 11 A structure schematic diagram after the photoresist mask is removed for a preferred embodiment of the present application.

[0059] Figure 10. Substrate; 11. First opening; 12. Photoresist mask; 13. First intermediate via structure; 131. Second intermediate via structure; 14. First polymer layer; 15. Second opening; 16. Second polymer layer; 17. Via. DETAILED DESCRIPTION

[0060] The existing glass through via (TGV) etching process usually uses plasma of fluorine-containing gas such as CF4 and SF6 to perform non-periodic cyclic etching on a glass substrate. Since one-step continuous etching is performed using a polymer-forming gas such as CF4 or SF6 which has relatively light polymer-forming property, the selectivity of photoresist is low (main reasons: firstly, such gas cannot provide sufficient polymer to protect photoresist, and secondly, ions contained in the plasma have energy and can cause a large degree of bombardment on photoresist), and it is difficult to etch a deep TGV structure. If a polymer-forming gas with relatively heavy polymer-forming property such as C4F8 and C4F6 is used, although it can provide good protection for photoresist, too much polymer formed during non-periodic cyclic etching can cause the etching angle to deviate, and even cause the problem of "etching stop". Therefore, from the perspective of ensuring etching, the existing TGV etching process can only use a polymer-forming gas with relatively light polymer-forming property, but this brings the problem of low photoresist selectivity, and therefore a metal mask with higher etching resistance is used for TGV etching. Moreover, the non-periodic cyclic etching has the disadvantage that the size uniformity of the etched TGV is relatively poor (generally a large upper and small lower morphology is formed), which affects the realization of the limit high aspect ratio etching, and thus it is difficult to meet the increasing demand for larger aspect ratio and higher interconnection density.

[0061] To solve the problems in the prior art, the embodiments of the present application provide a method for preparing a high aspect ratio glass through via, comprising:

[0062] providing a substrate of glass material;

[0063] forming a plurality of photoresist masks on the surface of the substrate, and the adjacent two photoresist masks have a first opening therebetween;

[0064] performing an etching process to etch the surface of the substrate exposed in the first opening, and forming a through via on the substrate;

[0065] wherein the etching process comprises a plurality of periodic cyclic etching steps formed in sequence by a first etching step and a second etching step;

[0066] the first etching step uses plasma of a first gas from which charged particles are filtered to perform isotropic first etching on the substrate, and forms a first polymer layer on the inner wall of the through via being formed and the photoresist mask to protect the inner wall and the photoresist mask during the first etching;

[0067] The second etching step uses plasma of a second gas to perform anisotropic second etching on the first polymer layer on the bottom of the inner wall to form a second opening on the bottom and expose the substrate to perform the first etching again through the second opening;

[0068] wherein, after each first etching step in the periodic cycle etching step is completed for a first preset number of times, a processing process is performed once on the forming via to improve the smoothness of the sidewall;

[0069] wherein, the first gas is a first fluorocarbon gas with a fluorocarbon ratio greater than or equal to 1:3, and the second gas is a chlorine-based gas.

[0070] The embodiment of the present application uses photoresist mask and an etching process including multiple periodic cycle etching steps formed in turn by first etching step and second etching step to etch the substrate, uses plasma of the first gas filtered of charged particles to perform isotropic first etching on the substrate, forms a first polymer layer on the inner wall of the forming via and the photoresist mask, and uses plasma of the second gas to perform anisotropic second etching on the first polymer layer on the bottom of the inner wall to expose the underlying substrate to perform the first etching again. The selectivity of the photoresist mask can be significantly improved, so that the photoresist mask can replace the traditional metal hard mask to form a via (glass via) with a higher aspect ratio on the substrate, and the etching uniformity and perpendicularity can be improved, the pollution problem when using metal mask can be avoided, the process is simplified, and the efficiency is improved.

[0071] The embodiment of the present application also provides a glass via obtained by using the preparation method of the high-aspect-ratio glass via.

[0072] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0073] Reference Figure 1 The embodiment of the present application provides a preparation method of a high-aspect-ratio glass via, which includes the following steps in turn:

[0074] Step S11: providing a substrate of glass material.

[0075] Reference Figure 2 The substrate 10 of glass material (glass substrate) is used to further form a via (glass via (TGV)) on the substrate 10 by performing an etching process.

[0076] In some embodiments, the via can be a high-aspect-ratio via (for example, the aspect ratio can be greater than 50:1).

[0077] In some embodiments, the glass material includes SiO2, etc.

[0078] Step S12: Forming a plurality of photoresist masks on the surface of the substrate.

[0079] Reference Figure 2 In some embodiments, a spin coating process can be employed to form a photoresist layer on the upper surface of the substrate 10. Then, a photolithography process is employed to perform photolithography on the photoresist layer, thereby forming a plurality of photoresist patterns, i.e. photoresist masks 12, on the upper surface of the substrate 10. Wherein, any two adjacent photoresist masks 12 have a first opening 11 for etching the substrate 10, and the surface of the substrate 10 between the two adjacent photoresist masks 12 is exposed on the bottom of the first opening 11.

[0080] It should be noted that, Figure 2 It should be noted that,

[0081] Step S13: Using the plasma of the first gas filtered of charged particles to perform isotropic first etching on the substrate, and forming a first polymer layer on the inner wall of the forming via and the photoresist mask.

[0082] In some embodiments, by performing the etching process and using the photoresist mask 12 as a mask, the surface of the substrate 10 exposed in the first opening 11 between the adjacent photoresist masks 12 is periodically etched to form a via (glass via) with a high aspect ratio on the substrate 10.

[0083] The etching process includes a plurality of periodic etching steps formed by the first etching step and the second etching step in sequence. That is, by repeatedly performing the first etching step and the second etching step in sequence, a plurality of periodic etching steps performed by the first etching step and the second etching step in sequence are formed. Wherein, the first etching step is used to perform first etching on the substrate 10, and form a first polymer layer on the inner wall of the forming via (intermediate via structure) and the entire exposed surface of the photoresist mask 12, so as to protect the inner wall of the forming via and the photoresist mask 12 when performing the first etching.

[0084] Therefore, in the etching process of the embodiments of the present application, the deposition step provided in the conventional periodic etching process is no longer independently arranged.

[0085] Reference Figure 3In some embodiments, a first etching step in the etching process is performed using a plasma containing a first gas from which charged particles have been filtered out, i.e., using neutral particles from the plasma containing the first gas. Using a photoresist mask 12 as a mask, and through a first opening 11, isotropic first etching is performed on the substrate 10 to form a first intermediate via structure 13 (the first intermediate via structure 13). Simultaneously, taking advantage of the high polymer-forming properties of the first gas, a first polymer layer 14 is formed on the inner wall of the first intermediate via structure 13 (the via under formation) and on the entire exposed surface of the photoresist mask 12 (for emphasis, ...). Figure 3 Only the first polymer layer 14 located on the inner wall of the first intermediate via structure 13 and the top surface of the photoresist mask 12 is shown. The first polymer layer 14 deposited on other parts (such as the side surface of the photoresist mask 12 and the exposed bottom surface at the junction with the top of the first intermediate via structure 13) is omitted from the display. This is to protect the inner wall of the first intermediate via structure 13 and the photoresist mask 12 during the first etching step. In other words, in this embodiment, the first gas used in the first etching step is used both to etch the substrate 10 to form the first intermediate via structure 13 and to form the first polymer layer 14 to protect the inner wall of the first intermediate via structure 13 and the photoresist mask 12.

[0086] By ionizing the first gas introduced into the process chamber, a plasma of the first gas is obtained. Then, by activating the ion filtering function of the process chamber, ion filtering is performed to remove charged particles such as ions from the plasma formed by the first gas, resulting in neutral particles. Using the neutral particles from the obtained plasma of the first gas, an isotropic first etching is performed on the substrate 10, forming a first intermediate via structure 13 on the substrate 10. Simultaneously, a first polymer layer 14 is formed on the inner wall of the first intermediate via structure 13 and on the surface of the photoresist mask 12.

[0087] In some embodiments, the first gas is a first fluorocarbon gas with a carbon-to-fluorine ratio greater than or equal to 1:3. For example, the first fluorocarbon gas may include at least one of C4F8, C4F6, C5F8, CHF3, and CH2F2, and He may be used as an auxiliary gas. That is, fluorine radicals (neutral particles) in the plasma formed by the first fluorocarbon gas can be used to perform the first etching and deposit the first polymer layer 14 on the substrate 10, with He as the auxiliary gas.

[0088] In some embodiments, the first etching step is performed using a first temperature, a first pressure, a first source power, and a first bias power. Wherein the first temperature is greater than 0°C, the first pressure is greater than a pressure (second pressure) at which the second etching step is performed, and the first source power is greater than a source power (second source power) at which the second etching step is performed, and the first bias power is less than a bias power (second bias power) at which the second etching step is performed.

[0089] In some embodiments, the first temperature is 50°C to 90°C. For example, the first temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C, or any value between any two of the aforementioned temperatures. However, the present application is not limited thereto.

[0090] In some embodiments, the first pressure is 100 mTorr to 1 Torr. For example, the first pressure can be 100 mTorr, 200 mTorr, 300 mTorr, 400 mTorr, 500 mTorr, 600 mTorr, 700 mTorr, 800 mTorr, 900 mTorr, or 1 Torr, or any value between any two of the aforementioned pressures. However, the present application is not limited thereto.

[0091] In some embodiments, the first source power is 1000 W to 3000 W. For example, the first source power can be 1000 W, 1200 W, 1500 W, 2000 W, 2500 W, or 3000 W, or any value between any two of the aforementioned source powers. However, the present application is not limited thereto.

[0092] In some embodiments, the first bias power is 0 W (bias power is turned off).

[0093] In some embodiments, the total flow rate of the first gas (including the first fluorocarbon gas and the auxiliary gas) is 50 sccm to 1000 sccm. For example, the total flow rate of the first gas can be 50 sccm, 60 sccm, 80 sccm, 100 sccm, 300 sccm, 500 sccm, 700 sccm, or 1000 sccm, or any value between any two of the aforementioned flow rates. However, the present application is not limited thereto.

[0094] In some embodiments, when the first fluorocarbon gas includes any one of C4F8, C4F6, C5F8, CHF3, CH2F2, and He is used as the auxiliary gas, the following flow rate ratio relationships can be obtained: C4F8:He = 3:1 to 4:1; or, C4F6:He = 5:1 to 6:1; or, C5F8:He = 5:1 to 6:1; or, CHF3:He = 1:1 to 2:1; or, CH2F2:He = 2:1 to 3:1. However, the present application is not limited thereto.

[0095] The present embodiment can reduce the bombardment on the photoresist mask 12 by using the plasma of the first gas filtered of charged particles (neutral particles) for isotropic first etching of the substrate 10 with the bias power turned off (the first bias power is 0 W), and can enhance polymer formation by the high carbon-fluorine ratio of the first gas, form a relatively heavy first polymer layer 14 on the inner wall of the first intermediate via structure 13 and the exposed surface of the photoresist mask 12 during etching, and provide good protection for the photoresist mask 12, so that the photoresist mask 12 has a high selectivity, thereby playing a dual role of etching and protection and expanding the process window. At the same time, by using the non-directional characteristics of neutral particles, isotropic etching of approximately 1:1 in the vertical and horizontal directions can be achieved to obtain an etching morphology of the first intermediate via structure 13 close to a bowl shape (reference Figure 3 ), and the first polymer layer 14 covering the inner wall of the first intermediate via structure 13 can prevent the first etching from continuing, thereby ensuring the uniformity of the size in each cycle. Therefore, the present embodiment can not only control the degree of lateral etching, but also eliminate the separate and indispensable deposition step in the traditional periodic cycle etching process, and only use the same set of process gas (first gas) system to complete the etching and deposition processes that normally require two sets of process gas (etching gas + deposition gas) systems, thereby greatly simplifying the process, improving the efficiency, and reducing the control difficulty.

[0096] Step S14: Perform anisotropic second etching of the first polymer layer on the inner wall bottom using plasma of the second gas, and expose the substrate on the bottom to perform first etching again.

[0097] The second etching step in the etching process is used to perform anisotropic second etching of the first polymer layer 14 on the inner wall bottom of the forming via (first intermediate via structure 13), form a second opening on the first polymer layer 14 on the bottom of the forming via, and expose the substrate 10 located below the second opening to perform first etching again through the second opening. Thus, the first etching can be performed again to continue etching downward, thereby eliminating the problem of difficulty in continuous etching downward caused by the previous isotropic etching. By repeatedly performing the first etching step and the second etching step multiple times, a higher aspect ratio via can be prepared on the substrate 10, which is difficult to achieve by conventional processes.

[0098] Reference Figure 4In some embodiments, a second etching step in the etching process is performed, using plasma of a second gas, specifically, using charged particles in the plasma of the second gas, to anisotropically etch the first polymer layer 14 on the bottom of the first first intermediate via structure 13, with the photoresist mask 12 as a mask and through the first opening 11, to etch through the first polymer layer 14 covering the bottom of the first first intermediate via structure 13, so as to form a second opening 15 in the first polymer layer 14 on the bottom of the first first intermediate via structure 13, exposing the substrate 10 under the second opening 15. In this way, the first etching can be performed again through the second opening 15, and a second first intermediate via structure 13 can be successively formed on the substrate 10 under the second opening 15 (under the first first intermediate via structure 13), as shown in FIG. 2B, and so on, so as to form a high aspect ratio via on the substrate 10. Figure 5

[0099] The second gas is ionized to obtain plasma of the second gas, and the ion filtering function of the process chamber is closed, i.e., the ion filtering is cancelled, so that the ions contained in the plasma formed by the second gas are retained to obtain charged particles. The charged particles in the obtained plasma of the second gas are used to perform the isotropic first etching of the first polymer layer 14 on the bottom of the first first intermediate via structure 13, and form a through second opening 15 in the first polymer layer 14 on the bottom of the first first intermediate via structure 13.

[0100] In some embodiments, the second gas is a chlorine-based gas. For example, the second gas can be BCl3. That is, the charged particles (ions) in the plasma of BCl3 are used to perform the isotropic first etching of the first polymer layer 14 on the bottom of the first intermediate via structure 13, and form the second opening 15.

[0101] In some embodiments, the second etching step is performed using a second temperature, a second pressure, a second source power and a second bias power. The second temperature is greater than 0°C (the second temperature can be the same as or different from the first temperature), the second pressure is less than the first pressure, the second source power is less than the first source power, and the second bias power is greater than the first bias power.

[0102] In some embodiments, the second temperature is 50°C to 90°C. For example, the second temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, or any value between any two of the foregoing temperatures. However, the present application is not limited thereto.

[0103] ​In some embodiments, the second pressure is 10 mTorr to 100 mTorr. For example, the second pressure can be 10 mTorr, 20 mTorr, 30 mTorr, 40 mTorr, 50 mTorr, 60 mTorr, 70 mTorr, 80 mTorr, 90 mTorr, or 100 mTorr, or any value between any two of the foregoing pressure values. However, the application is not limited thereto.

[0104] In some embodiments, the second source power is 500 W to 1000 W. For example, the second source power can be 500 W, 600 W, 700 W, 800 W, 900 W, or 1000 W, or any value between any two of the foregoing source power values. However, the application is not limited thereto.

[0105] In some embodiments, the second bias power is 50 W to 100 W. For example, the second bias power can be 50 W, 60 W, 70 W, 80 W, 90 W, or 100 W, or any value between any two of the foregoing bias power values. However, the application is not limited thereto.

[0106] In some embodiments, the total flow rate of the second gas is 50 sccm to 1000 sccm. For example, the total flow rate of the second gas can be 50 sccm, 60 sccm, 90 sccm, 100 sccm, 200 sccm, 500 sccm, 800 sccm, or 1000 sccm, or any value between any two of the foregoing flow rate values. However, the application is not limited thereto.

[0107] The embodiments of the application can, by using the second gas to perform anisotropic second etching under a certain bias power (the second bias power is 50 W to 100 W), not only direct bombard the inner wall bottom of the forming via hole to remove the first polymer layer 14 on the inner wall bottom and expose the underlying substrate 10 for the first etching again, but also take advantage of the characteristic that BCl3 has little etching effect on the substrate 10 (relative to conventional etching gases such as fluorine-containing gas) to avoid damaging the formed etching morphology and prevent the problem of increasing the size of the upper part with repeated etching, thereby ensuring the etching uniformity and perpendicularity, and thus being more conducive to realizing the etching structure (glass via hole) with higher aspect ratio and higher interconnection density on the substrate 10 which is difficult to achieve by conventional processes.

[0108] Step S15: After each first etching of the first preset number of times, a processing process is performed on the forming via hole to improve the smoothness of the sidewall.

[0109] Due to the unique process characteristics of the periodic etching process of the present application, after each execution of the process of steps S13 to S14, i.e. after each continuous execution of the first etching step to the second etching step, a regular tooth-like pattern (protruding part) will be formed on the sidewall of the forming via hole, and the tooth-like pattern has a certain protruding degree (nanometer level) (see Figure 5 , Figure 9 ). Therefore, by performing a processing process on the forming via hole after each completion of the first etching step in the first preset number of periodic etching steps, the sidewall of the forming via hole can be processed to improve the smoothness of the sidewall of the forming via hole, thereby improving the smoothness of the sidewall of the finally formed via hole.

[0110] In some embodiments, the first preset number is 1 or 2.

[0111] In some embodiments, by performing the processing process, at least part of the tooth-like pattern present on the sidewall of the forming via hole (first intermediate via hole structure 13) is removed. The processing process includes a deposition step and a third etching step; the deposition step is used to deposit a second polymer layer on the sidewall of the forming via hole using a plasma of a third gas; the third etching step is used to remove a part of the thickness of the second polymer layer deposited on the sidewall using a plasma of a fourth gas, and react with the substrate material present and exposed on the surface of the tooth-like pattern on the sidewall to remove at least part of the tooth-like pattern.

[0112] Referring to Figure 6 In some embodiments, by ionizing the third gas introduced into the process chamber to obtain a plasma of the third gas, and closing the ion filtering function of the process chamber, i.e. canceling the execution of the ion filtering, the second polymer layer 16 is deposited on the sidewall of the first intermediate via hole structure 13 and the second intermediate via hole structure 13 (for emphasis, Figure 6 only the second polymer layer 16 on the inner wall of the first intermediate via hole structure 13 and the top surface of the photoresist mask 12 is shown). The deposited second polymer layer 16 will be located on the first polymer layer 14. By depositing the second polymer layer 16, the overall thickness of the polymer on the sidewall can be adjusted, which not only forms a protection for the sidewall, but also lays a foundation for the execution of the third etching step.

[0113] Then, by ionizing the fourth gas introduced into the process chamber to obtain a plasma of the fourth gas, and turning off the ion filtering function of the process chamber (i.e., canceling the ion filtering), the plasma of the fourth gas containing charged particles removes a portion of the thickness of the second polymer layer 16 deposited on the sidewall (and may also remove a portion of the thickness of the first polymer layer 14 deposited on the sidewall), and reacts with the substrate material of the exposed serrated surface on the sidewall to remove at least part of the serrations. By repeating the deposition step and the third etching step sequentially multiple times, the serrations on the sidewall can be completely or substantially removed. After processing the sidewalls of the first first intermediate via structure 13 and the second first intermediate via structure 13, a second intermediate via structure 131 with smooth sidewalls is obtained, as shown below. Figure 7 As shown. On the sidewall of the second intermediate through-hole structure 131, there are still a second polymer layer 16 and a first polymer layer 14 of a certain thickness, which play a role in adjusting the thickness uniformity of the polymer on the sidewall, effectively preventing lateral etching, thereby ensuring the uniformity of dimensions.

[0114] Subsequently, by performing the second etching step in the second periodic etching step, a second second opening 15 is formed on the bottom of the second intermediate through-hole structure 131, that is, on the bottom of the second first intermediate through-hole structure 13 after sidewall treatment, as shown. Figure 8 As shown, after completing the entire second cycle etching step (after performing the second etching step in the second cycle etching step, there will be residue in both the second polymer layer 16 and the first polymer layer 14; for simplicity, this is not shown here), Figure 8 (And the second polymer layer 16 is omitted from the following figures).

[0115] In some embodiments, the third gas is a second fluorocarbon gas with a carbon-to-fluorine ratio greater than or equal to 1:2. For example, the second fluorocarbon gas may include at least one of C4F8, C4F6, C5F8, and CH3F, and N2 may be used as an auxiliary gas. By adding N2 to the second fluorocarbon gas, the third gas can primarily function as a polymer deposition agent (forming CN polymers or CHN polymers, and spontaneously dissociating to generate C-containing polymers) to form the second polymer layer 16.

[0116] By using a gas with strong polymer-forming ability as the third gas, a second polymer layer 16 can be deposited on the sidewall to prevent the etching reaction from continuing, thereby protecting the sidewall from lateral etching and preventing the problem of size expansion.

[0117] In some embodiments, the fourth gas is a fluorine-based gas with weak polymer-forming ability. For example, the fourth gas can include SF6, and Ar can be used as an auxiliary gas. With SF6, a portion of the second polymer layer 16 on the sidewall can be removed to expose the end of the tooth-like pattern, and can react with the substrate 10 material (SiO2) exposed thereat, so that at least a portion of the tooth-like pattern can be removed.

[0118] In some embodiments, when performing the processing process, the deposition step and the third etching step are repeatedly performed for a second preset number of times (1 cycle is defined as 1 deposition step and 1 third etching step are performed in succession).

[0119] In some embodiments, the second preset number of times is 10-20 times. For example, the second preset number of times can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 times. Alternatively, the second preset number of times can be less than 10 times or more than 20 times (depending on the protrusion of the tooth-like pattern).

[0120] In some embodiments, the deposition step is performed using a third pressure that is high pressure, and the third etching step is performed using a fourth pressure that is low pressure, the third pressure is greater than the first pressure, and the first pressure is greater than the second pressure and the fourth pressure. The sidewall has a recessed portion between adjacent tooth-like patterns. By using the third pressure that is high pressure in the deposition step and turning off the bias power, the third gas can be made to stay and accumulate on the sidewall surface at the recessed portion where the flow rate is relatively weak, and the flow rate of the third gas is relatively fast on the sidewall surface at the end of the tooth-like pattern, and the structure at the end of the tooth-like pattern is special, and the polymer has relatively few attachment points, so the deposition of the second polymer layer 16 at the end of the tooth-like pattern is very little, and the thickness is relatively thin. Since a portion of the second polymer layer 16 on the sidewall is consumed when the fourth gas is used, by using the fourth pressure that is low pressure and applying a relatively large bias power, the flow rate of the fourth gas can be accelerated and given directionality, so that the etching is mainly concentrated on the end of the tooth-like pattern (because the polymer deposited at the end of the tooth-like pattern is inherently less, and the end of the tooth-like pattern is exposed due to the consumption of the polymer by the fourth gas). The sidewall surface at the recessed portion is protected effectively when the third etching step is performed because of the relatively thick second polymer layer 16 thereat.

[0121] In some embodiments, the deposition step is performed using a third temperature, a third pressure, a third source power, and a third bias power.

[0122] In some embodiments, the third temperature is 10°C to 20°C. For example, the third temperature can be 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, or any value between any two of the foregoing. However, the present application can not be limited to this.

[0123] In some embodiments, the third pressure is 1 Torr to 5 Torr. For example, the third pressure can be 1 Torr, 1.3 Torr, 1.5 Torr, 1.7 Torr, 2 Torr, 3 Torr, 4 Torr, or 5 Torr, or any value between any two of the foregoing. However, the present application can not be limited to this.

[0124] In some embodiments, the third source power is 100 W to 500 W. For example, the third source power can be 100 W, 200 W, 300 W, 400 W, or 500 W, or any value between any two of the foregoing. However, the present application can not be limited to this.

[0125] In some embodiments, the third bias power is 0 W (bias power is turned off).

[0126] In some embodiments, the total flow rate of the third gas (including the second fluorocarbon gas and the auxiliary gas) is 100 sccm to 500 sccm. For example, the total flow rate of the third gas can be 100 sccm, 200 sccm, 300 sccm, 400 sccm, or 500 sccm, or any value between any two of the foregoing. However, the present application can not be limited to this.

[0127] In some embodiments, when the third gas includes any one of C4F8, C4F6, C5F8, CH3F, and N2 is used as the auxiliary gas, the following flow rate ratio relationship can be used: C4F8:N2 = 1:8 to 1:10; or C4F6:N2 = 1:3 to 1:5; or C5F8:N2 = 1:3 to 1:5; or CH3F:N2 = 1:2 to 1:5. However, the present application can not be limited to this.

[0128] In some embodiments, a fourth etching step is performed using a fourth temperature, a fourth pressure, a fourth source power, and a fourth bias power.

[0129] In some embodiments, the fourth temperature is 10°C to 20°C. For example, the fourth temperature can be 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, or any value between any two of the foregoing. However, the present application can not be limited to this.

[0130] In some embodiments, the fourth pressure is 30 mTorr to 100 mTorr. For example, the fourth pressure can be 30 mTorr, 40 mTorr, 50 mTorr, 60 mTorr, 70 mTorr, 80 mTorr, 90 mTorr, or 100 mTorr, or any value between any two of the foregoing pressure values. However, the present application can not be limited to this.

[0131] In some embodiments, the fourth source power is 100 W to 1000 W. For example, the fourth source power can be 100 W, 200 W, 300 W, 400 W, 500 W, 600 W, 700 W, 800 W, 900 W, or 1000 W, or any value between any two of the foregoing source power values. However, the present application can not be limited to this.

[0132] In some embodiments, the fourth bias power is 1000 W to 2000 W. For example, the fourth bias power can be 1000 W, 1100 W, 1200 W, 1300 W, 1400 W, 1500 W, 1600 W, 1700 W, 1800 W, 1900 W, or 2000 W, or any value between any two of the foregoing bias power values. However, the present application can not be limited to this.

[0133] In some embodiments, the total flow rate of the fourth gas (including the fluorine-based gas and the auxiliary gas) is 50 sccm to 200 sccm. For example, the total flow rate of the fourth gas can be 50 sccm, 60 sccm, 80 sccm, 100 sccm, 120 sccm, 150 sccm, 170 sccm, or 200 sccm, or any value between any two of the foregoing flow rate values. However, the present application can not be limited to this.

[0134] In some embodiments, when the fourth gas includes SF6and Ar is used as the auxiliary gas, the following flow rate ratio relationship can be obtained: SF6: Ar = 1: 10 to 1: 20. However, the present application can not be limited to this.

[0135] Step S16: Steps S13 to S15 are repeatedly performed until the via hole is formed on the substrate.

[0136] Reference Figure 9 In some embodiments, in step S13, the fourth pressure is 30 mTorr to 100 mTorr, the fourth source power is 100 W to 1000 W, the fourth bias power is 1000 W to 2000 W, and the total flow rate of the fourth gas is 50 sccm to 200 sccm. Figure 8On the basis of the structure shown, the above step S13 is repeated, i.e. the first etching step of the third periodic cycle etching step in the etching process is repeated, using the neutral particles in the plasma of the first gas, with the photoresist mask 12 as a mask, and through the first opening 11 and the second second opening 15 (located on the bottom of the second intermediate via structure 131), the substrate 10 exposed below the second second opening 15 is subjected to isotropic first etching again, and a third first intermediate via structure 13 is formed in succession on the substrate 10 below the second second opening 15 (below the second intermediate via structure 131). At the same time, the first polymer layer 14 is formed on the inner wall of the third first intermediate via structure 13 (including the second intermediate via structure 131) and the entire exposed surface of the photoresist mask 12 by virtue of the strong polymer-forming ability of the first gas.

[0137] Next, the above step S14 is repeated, i.e. the second etching step of the third periodic cycle etching step in the etching process is repeated, using the charged particles in the plasma of the second gas, with the photoresist mask 12 as a mask, and through the first opening 11 and the second second opening 15, the first polymer layer 14 on the bottom of the third first intermediate via structure 13 is subjected to anisotropic second etching, and the first polymer layer 14 covering the bottom of the third first intermediate via structure 13 is etched through, so that a second opening 15 (third second opening 15) is also formed on the first polymer layer 14 at the bottom of the third first intermediate via structure 13, exposing the substrate 10 below the second opening 15.

[0138] By analogy, by continuing to repeat the above steps S13 to S14, a fourth first intermediate via structure 13 and the like can be formed in succession below the third first intermediate via structure 13, as shown. Figure 9 And after every 1 or 2 first intermediate via structures 13 are formed below the second intermediate via structure 131, a processing process is performed once.

[0139] Finally, a via hole 17 with a target aspect ratio and a smooth sidewall, i.e. a glass via hole (TGV), composed of a plurality of first intermediate via structures 13 after sidewall processing in succession, is formed from top to bottom on the glass material substrate 10, as shown. Figure 10

[0140] ​By performing the periodic cycle of the deposition step and the third etching step and the alternating cycle with the etching process, the etching rate and the sidewall quality are balanced, so as to realize high etching rate and high etching precision (atomic level precision) of the high aspect ratio glass via hole, effectively improve the uniformity and roughness of the local polymer, solve the line width offset problem, realize higher verticality, and realize better uniformity (uniform size of upper, middle and lower positions of the high aspect ratio glass via hole), better sidewall smoothness, and improved device performance.

[0141] It should be noted that when the last cycle (the last periodic cycle etching step) before forming the via hole 17 is performed, since it is unnecessary to form the second opening 15 on the bottom of the last first intermediate via hole structure 13, the second etching step can be omitted (default) when the last cycle is performed. That is, after the formation and execution of the processing process of the lowermost one of the first intermediate via hole structures 13, the second opening 15 can not be formed on the bottom of the lowermost one of the first intermediate via hole structures 13.

[0142] In some embodiments, the etching process based on the multiple periodic cycle etching steps only includes the above-mentioned first etching step and second etching step in sequence, and does not contain other etching steps for etching the substrate 10 and other deposition steps for depositing the first polymer layer 14 independently (the processing process is an independent process embedded in the etching process).

[0143] In some embodiments, the etching process includes a first etching stage, a second etching stage and a third etching stage connected in sequence, which are respectively used to form the top, middle and bottom of the via hole in sequence. And the carbon fluoride ratio of the first fluorocarbon gas used in the first etching step in the first etching stage, the carbon fluoride ratio of the first fluorocarbon gas used in the first etching step in the second etching stage and the carbon fluoride ratio of the first fluorocarbon gas used in the first etching step in the third etching stage increase in sequence.

[0144] Further, the carbon fluoride ratio of the second fluorocarbon gas used in the deposition step of the processing process performed in the first etching stage, the carbon fluoride ratio of the second fluorocarbon gas used in the deposition step of the processing process performed in the second etching stage and the carbon fluoride ratio of the second fluorocarbon gas used in the deposition step of the processing process performed in the third etching stage increase in sequence.

[0145] For example, in the first etching stage, the first gas used in the first etching step can include a first fluorocarbon gas with a fluorocarbon ratio equal to 1:3, such as CHF3, etc.; in the second etching stage, the first gas used in the first etching step can include a first fluorocarbon gas with a fluorocarbon ratio equal to 1:2, such as C4F8, CH2F2, etc.; in the third etching stage, the first gas used in the first etching step can include a first fluorocarbon gas with a fluorocarbon ratio greater than 1:2, such as C4F6, C5F8, etc.

[0146] Similarly, in the first etching stage, the third gas used in the deposition step can include a second fluorocarbon gas with a fluorocarbon ratio equal to 1:2, such as C4F8, etc.; in the second etching stage, the third gas used in the deposition step can include a second fluorocarbon gas with a fluorocarbon ratio greater than 1:2 and less than 1:1, such as C4F6, C5F8, etc.; in the third etching stage, the third gas used in the deposition step can include a second fluorocarbon gas with a fluorocarbon ratio equal to 1:1, such as CH3F, etc. Alternatively, CH4, etc. can also be used.

[0147] In this way, as the etching depth of the via being formed increases, the deposition can be enhanced by providing a higher fluorocarbon ratio, which can effectively inhibit lateral etching of the sidewall bottom, eliminate the problem of bottom side etching, and further ensure the size uniformity and verticality in the depth direction.

[0148] Therefore, by performing the etching process in stages, not only the limitations of the conventional single etching process that cannot achieve high-precision control are overcome, but also a more precise and controllable etching scheme is provided for the manufacture of high-performance devices, effectively expanding the etching process window, and facilitating the realization of a glass via with a higher aspect ratio and a higher interconnection density.

[0149] Step S17: removing the photoresist mask.

[0150] Reference Figure 11 In some embodiments, the photoresist mask 12 on the surface of the substrate 10 is removed using a plasma of a fifth gas. The plasma of the fifth gas is obtained by ionizing the fifth gas introduced into the process chamber. After the photoresist mask 12 is removed, a via 17, i.e., a through glass via (TGV), is formed on the surface of the substrate 10.

[0151] In some embodiments, the fifth gas includes an oxidizing gas. For example, the fifth gas can include O2, etc.

[0152] According to a second aspect of the present application, the embodiments of the present application also provide a through glass via obtained using the method for manufacturing a high-aspect-ratio through glass via according to any one of the embodiments of the first aspect.

[0153] Reference Figure 11In some embodiments, the glass through via (TGV) is the through via 17. The through via 17 is formed on the surface of the substrate 10 and is further processed to improve the smoothness of the sidewall.

[0154] In some embodiments, the substrate 10 with the glass through via (the through via 17) can be applied in the fields of high-frequency communication, optoelectronics, 3D integration and advanced packaging, etc.

[0155] In a third aspect, the embodiments of the present application further provide a plasma processing device for performing the preparation method of the high aspect ratio glass through via corresponding to the above-mentioned embodiments to form the through via 17 (glass through via) corresponding to the above-mentioned embodiments. The plasma processing device includes an inductively coupled plasma (ICP) etching device or a capacitively coupled plasma (CCP) etching device, etc.

[0156] In other aspects, the embodiments of the present application further provide an electronic device including the glass through via (the through via 17) obtained by using the preparation method of the high aspect ratio glass through via according to the above-mentioned embodiments. The electronic device can be a storage device, a mobile phone, a computer, a tablet computer, an electronic instrument, a television, an artificial intelligence device, etc.

[0157] In summary, by using the photoresist mask 12 and using the plasma of the first gas filtered of charged particles, the surface of the substrate 10 exposed in the first opening 11 between the two adjacent photoresist masks 12 is isotropically first etched, and the first polymer layer 14 is formed on the inner wall of the forming through via and the photoresist mask 12, and by using the plasma of the second gas, the first polymer layer 14 on the bottom of the inner wall is anisotropically second etched to form the second opening 15 to expose the underlying substrate 10, so that the first etching is performed again through the second opening 15, which can significantly improve the selectivity of the photoresist mask 12, so that the photoresist mask can replace the traditional metal hard mask, and by sequentially repeating the first etching step and the second etching step, the through via 17 (glass through via) with a higher aspect ratio can be formed on the substrate 10, the etching uniformity and perpendicularity can be improved, the pollution problem when using the metal mask can be avoided, the process is simplified, and the efficiency is improved. Moreover, by performing a processing process on the forming through via after completing the first etching step in each first preset number of periodic etching steps, a better sidewall smoothness is achieved, and the device performance is improved.

[0158] The above is only the preferred embodiments of the present application, and the embodiments are not intended to limit the protection scope of the present application, so any equivalent changes made according to the content of the specification and drawings of the present application should also be included in the protection scope of the present application.

Claims

1. A method of fabricating a high aspect ratio glass via, comprising: The method comprises: providing a substrate of glass material; forming a plurality of photoresist masks on a surface of the substrate, with a first opening between any two adjacent photoresist masks; performing an etching process to etch the surface of the substrate exposed in the first opening, and form a via on the substrate; wherein the etching process comprises a plurality of periodic cycle etching steps formed in sequence by a first etching step and a second etching step; the first etching step uses plasma of a first gas filtered of charged particles to perform isotropic first etching on the substrate, and forms a first polymer layer on the inner wall of the via being formed and the photoresist mask, to protect the inner wall and the photoresist mask when the first etching is performed; the second etching step uses plasma of a second gas to perform anisotropic second etching on the first polymer layer on the bottom of the inner wall, form a second opening on the bottom, and expose the substrate to perform the first etching again through the second opening; wherein after each first preset number of the first etching step in the periodic cycle etching steps is completed, a processing process is performed on the via being formed to improve the smoothness of the sidewall; wherein the first gas is a first fluorocarbon gas with a fluorocarbon ratio greater than or equal to 1:3, and the second gas is a chlorine-based gas.

2. The method of claim 1, wherein, The processing process comprises a deposition step and a third etching step; the deposition step comprises using plasma of a third gas to deposit a second polymer layer on the sidewall of the via being formed, and the third etching step comprises using plasma of a fourth gas to remove a partial thickness of the second polymer layer deposited on the sidewall, and react with the substrate material existing and exposed on the protrusion surface on the sidewall to remove at least part of the protrusion; wherein the third gas is a second fluorocarbon gas with a fluorocarbon ratio greater than or equal to 1:2, and the fourth gas is a fluorine-based gas.

3. The method of claim 2, wherein the glass via has a depth-to-width aspect ratio of at least 10:

1. The first etching step is performed using a first pressure and a first bias power, the second etching step is performed using a second pressure and a second bias power, the deposition step is performed using a third pressure and a third bias power, and the third etching step is performed using a fourth pressure and a fourth bias power, the third pressure is greater than the first pressure, the first pressure is greater than the second pressure and the fourth pressure, the fourth bias power is greater than the second bias power, and the second bias power is greater than the first bias power and the third bias power.

4. The method of claim 3, wherein the glass via has a depth-to-width aspect ratio of at least 10:

1. The first pressure is 100 mTorr to 1 Torr; and / or, the first bias power is 0 W; and / or, the second pressure is 10 mTorr to 100 mTorr; and / or, the second bias power is 50 W to 100 W; and / or, the third pressure is 1 Torr to 5 Torr; and / or, the third bias power is 0 W; and / or, the fourth pressure is 30 mTorr to 100 mTorr; and / or, the fourth bias power is 1000 W to 2000 W.

5. The method of claim 2, wherein the glass via has a depth-to-width aspect ratio of at least 10:

1. The first fluorocarbon gas includes at least one of C4F8, C4F6, C5F8, CHF3, CH2F2, the chlorine-based gas includes BCl3, the second fluorocarbon gas includes at least one of C4F8, C4F6, C5F8, CH3F, and the fluorine-based gas includes SF6.

6. The method of claim 1, wherein the glass via has a depth-to-width aspect ratio of at least 10:

1. The first preset number of times is 1 or 2.

7. The method of claim 2, wherein the glass via has a depth-to-width aspect ratio of at least 10:

1. The deposition step and the third etching step are repeatedly performed in sequence for a second preset number of times each time the processing process is performed.

8. The method of claim 7, wherein the glass via is formed by a method comprising: The second preset number of times is 10-20.

9. The method of claim 2, wherein the glass via has a high aspect ratio. The etching process includes a first etching stage, a second etching stage and a third etching stage connected in sequence, for forming a top part, a middle part and a bottom part of the via connected in sequence, respectively, and the fluorocarbon ratio of the first fluorocarbon gas used in the first etching stage, the fluorocarbon ratio of the first fluorocarbon gas used in the second etching stage and the fluorocarbon ratio of the first fluorocarbon gas used in the third etching stage increase in sequence.

10. A glass via, characterized by, The method is used to prepare a high aspect ratio glass via. The first fluorocarbon gas includes at least one of C4F8, C4F6, C5F8, CHF3, CH2F2, the chlorine-based gas includes BCl3, the second fluorocarbon gas includes at least one of C4F8, C4F6, C5F8, CH3F, and the fluorine-based gas includes SF6.

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