Sensitive device structure and preparation method thereof and semiconductor device

Abstract

The present application relates to a sensitive device structure and a method for preparing the same, as well as a semiconductor device. The method for preparing the sensitive device structure includes: forming a sensitive material layer on a substrate, and forming a patterned mask layer on the sensitive material layer; performing a main etching on the sensitive material layer based on the patterned mask layer under a first etching gas to form a device sensitive layer, wherein the first etching gas includes a first fluoride gas and a sidewall protection gas, and the sidewall protection gas in the first etching gas does not exceed 5% of the volume of the first fluoride gas; removing the patterned mask layer; and forming a passivation protection layer on the device sensitive layer. The present application can effectively reduce polymer residues in the sensitive device structure, thereby improving the performance of the sensitive device.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit technology, and in particular to a sensitive device structure and a preparation method thereof, as well as a semiconductor device. Background Art

[0002] In some semiconductor devices, a sensitive device structure including a device sensitive layer is provided, so that various signals are detected through the device sensitive layer. The device sensitive layer has an important influence on the performance of the sensitive device structure, and can be formed by an etching process.

[0003] However, the existing etching process often forms polymer residues during the process of forming the device sensitive layer. The polymer residues will cause the formation of holes or steps during the subsequent film deposition, thereby affecting the terminal electrical properties of the product, and seriously affecting the product reliability. Summary of the invention

[0004] Based on this, the embodiments of the present application provide a sensitive device structure and a preparation method thereof, as well as a semiconductor device that can reduce polymer residues.

[0005] A method for preparing a sensitive device structure, comprising:

[0006] forming a sensitive material layer and a patterned mask layer on the substrate in sequence;

[0007] Under a first etching gas, the sensitive material layer is mainly etched based on the patterned mask layer to form a device sensitive layer, wherein the first etching gas includes a first fluoride gas and a sidewall protection gas, and the volume proportion of the sidewall protection gas in the first etching gas does not exceed 5% of the volume proportion of the first fluoride gas;

[0008] removing the patterned mask layer;

[0009] A passivation protection layer is formed on the device sensitive layer.

[0010] In one embodiment, the first etching gas further includes an etching inhibition gas, and the etching inhibition gas is used to inhibit the reaction etching rate of the first fluoride gas. The volume proportion of the etching inhibition gas in the first etching gas does not exceed 5% of the volume proportion of the first fluoride gas.

[0011] In one embodiment, the etch inhibition gas includes oxygen.

[0012] In one embodiment, before the main etching of the sensitive material layer based on the patterned mask layer under the first etching gas, the method further includes:

[0013] Under the second etching gas, the sensitive material layer is pre-etched based on the patterned mask layer to form a pre-etched sidewall inclined outward in the sensitive material layer.

[0014] In one embodiment,

[0015] The second etching gas includes a sensitive layer etching gas and a mask layer etching gas, the sensitive layer etching gas is used for pre-etching the sensitive material layer, and the mask layer etching gas is used for etching the patterned mask layer.

[0016] In one embodiment, the sensitive layer etching gas includes a second fluoride gas, and the volume proportion of the second fluoride gas in the second etching gas is 70%-85%.

[0017] In one embodiment, the main etching and the pre-etching are performed in the same etching chamber. When performing the pre-etching and the main etching, the vacuum degree in the etching chamber is lower than 10 mTorr and the etching power is lower than 500 W.

[0018] In one embodiment, removing the patterned mask layer comprises:

[0019] Dry etching the patterned mask layer at a preset temperature, wherein the preset temperature is less than 200° C.;

[0020] The patterned mask layer is removed by a wet solution.

[0021] A sensitive device structure is formed according to any of the above methods.

[0022] A sensitive device comprises a sensitive device structure formed according to any of the methods described above.

[0023] The above-mentioned sensitive device structure and preparation method thereof and semiconductor device, since the first etching gas includes a first fluoride gas and a sidewall protection gas; the first fluoride gas is used to etch the sensitive material layer, and its reaction etching rate is fast, and the sidewall protection gas in the first etching gas does not exceed 5% of the volume of the first fluoride gas. Therefore, after the main etching, there is very little sidewall protection layer left on the sidewall of the device sensitive layer and it is easy to clean and remove. Therefore, after the passivation protection layer is subsequently formed on the device sensitive layer, there will be no polymer residue or only a small amount of polymer residue between the passivation protection layer and the device sensitive layer, so it is difficult to form holes or steps, etc. Therefore, the embodiment of the present application can effectively improve the reduction of polymer residues, thereby effectively improving the electrical properties and reliability of the product terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A flow chart of a method for preparing a sensitive device structure provided in an embodiment;

[0026] Figures 2 to 6 A schematic diagram of a structure of a sensitive device structure provided in an embodiment during preparation;

[0027] Figure 7 A scanning diagram of a sensitive device structure provided in an embodiment;

[0028] Figure 8 A scanning diagram of a structure before removing the patterned photoresist provided in an embodiment;

[0029] Fig. 9 A scanning image of a vanadium oxide layer forming polymer residue on the sidewall in the prior art;

[0030] Fig.10 This is a scanned image of a sensitive device structure after silicon nitride deposition in the prior art;

[0031] Fig.11 Scan of the structure before removing the patterned photoresist in the prior art. DETAILED DESCRIPTION

[0032] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0033] The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0034] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, doping type or part discussed below can be represented as a second element, component, region, layer or part.

[0035] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0036] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0037] Embodiments of the invention are described herein with reference to cross-sectional views which are schematic diagrams of ideal embodiments (and intermediate structures) of the present application, so that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances can be expected. Therefore, embodiments of the present application should not be limited to the specific shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing techniques. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges, rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Therefore, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shape of the region of the device, and do not limit the scope of the present application.

[0038] As mentioned in the background art, in the manufacturing process of existing sensitive devices, there is a problem that polymer residues affect the electrical performance and reliability of the product.

[0039] Specifically, for example, a temperature-sensitive device (or some photosensitive devices) may be provided with a vanadium oxide layer as the device sensitive layer. When the external temperature changes (or when light causes heat absorption), the resistance of the device sensitive layer (vanadium oxide layer) changes, thereby detecting the temperature (or light signal).

[0040] At present, the industry usually uses metal etching machines to etch vanadium oxide materials to form a vanadium oxide layer as a device sensitive layer. During etching, chloride gas is usually used as the main etching gas, and boron (B) chains are used for sidewall protection to control the shape of the vanadium oxide layer.

[0041] However, the etching speed of chloride gas and vanadium oxide is slow, and the B chain protective layer continues to accumulate on the etching side wall. Therefore, the B chain formed on the side wall of the vanadium oxide layer is relatively dense, which makes it easy to form polymer residues on the side wall of the vanadium oxide layer that are difficult to clean and remove (see Fig. 9 ), resulting in the formation of holes or steps during subsequent silicon nitride deposition (see Fig.10 ), thus affecting the electrical properties of the product terminal, and seriously affecting the product reliability. In addition, the angle between the side wall and the bottom surface of the device sensitive layer formed by etching is usually vertical and close to 90° (see Fig.11 ), which is not conducive to the deposition of the subsequent passivation protection layer.

[0042] Based on this, the embodiments of the present application provide a sensitive device structure and a preparation method thereof and a semiconductor device capable of reducing polymer residues.

[0043] It can be understood that the device sensitive layer in the embodiment of the present application includes but is not limited to a vanadium oxide layer, and the sensitive device includes but is not limited to a temperature sensitive device or a photosensitive device.

[0044] In one embodiment, see Figure 1 , providing a method for preparing a sensitive device structure, comprising:

[0045] Step S200, forming a sensitive material layer 201 and a patterned mask layer 300 on the substrate 100 in sequence, see Figure 2 ;

[0046] Step S400, under the first etching gas, the sensitive material layer 201 is mainly etched based on the patterned mask layer 300 to form the device sensitive layer 200, the first etching gas includes a first fluoride gas and a sidewall protection gas, and the volume of the sidewall protection gas in the first etching gas does not exceed 5% of the volume of the first fluoride gas, see Figure 4 ;

[0047] Step S600, removing the patterned mask layer 300, see Figure 5 ;

[0048] Step S800, forming a passivation protection layer 400 on the device sensitive layer 200, see Figure 6 .

[0049] In step S200, a sensitive material layer 201 may be first formed on the substrate 100, and then a patterned mask layer 300 may be formed on the sensitive material layer 201. When forming the patterned mask layer 300 on the sensitive material layer 201, a mask material layer may be first formed on the sensitive material layer 201, and then the mask material layer may be patterned to obtain the patterned mask layer 300.

[0050] Specifically, the patterned mask layer 300 may be a patterned photoresist layer. At this time, a photoresist layer may be coated on the sensitive material layer 201, and then the photoresist layer may be photolithographically processed to obtain a patterned photoresist layer.

[0051] In step S400 , the device sensitive layer may include but is not limited to a vanadium oxide layer.

[0052] The first etching gas includes a sidewall protection gas. During the etching process, the sidewall protection gas can be decomposed in the high-energy environment of the etching, and undergoes a polymerization reaction to form a protective film layer on the sidewall surface. For example, boron chloride (BCl 3 ) is used as a side wall protection gas, which decomposes into Cl ions and B ions under the high-energy etching environment. Cl ions can react with vanadium oxide, etc. to have an etching effect on vanadium oxide, while B ions can undergo a polymerization reaction to generate a B chain protection layer to protect the side wall.

[0053] At the same time, under the action of the electric field, the etching intensity of the plasma in the vertical direction is greater than the etching intensity in the horizontal direction. Therefore, during the etching process, the protective film layer formed at the bottom of the sensitive material layer 201 is etched away, while the protective film layer located on the side wall of the sensitive material layer 201 during the etching process remains on the side wall to form a side wall protection layer, preventing the plasma from etching laterally, thereby controlling the shape of the device sensitive layer 200 formed by the sensitive material layer 201.

[0054] Meanwhile, the first etching gas includes a first fluoride gas. The first fluoride gas is used to etch the sensitive material layer. The first fluoride gas is a fluoride gas. The fluoride gas has the characteristic of fast reaction etching rate.

[0055] Therefore, the first fluoride gas is used in combination with the sidewall protection gas to etch the sensitive material layer 201 not covered by the patterned mask layer 300, and the volume proportion of the sidewall protection gas in the first etching gas does not exceed 5% of the volume proportion of the first fluoride gas, so that the sidewall protection layer left on the sidewall of the device sensitive layer 200 is very small and easy to clean and remove.

[0056] In step S600 , during the process of removing the patterned mask layer 300 , the sidewall protection layer left on the sidewall of the device sensitive layer 200 in step S400 may also be removed simultaneously, thereby simplifying the process.

[0057] Of course, the sidewall protection layer remaining on the sidewall of the device sensitive layer 200 may also be cleaned by a separate cleaning process, and there is no limitation to this.

[0058] In step S800, the passivation protection layer 400 may include but is not limited to a silicon nitride layer. The passivation protection layer 400 can effectively passivate and protect the sensitive layer of the device.

[0059] In this embodiment, after the main etching, the sidewall protection layer left on the sidewall of the device sensitive layer 200 is very small and can be easily removed by cleaning. Therefore, after the passivation protection layer 400 is subsequently formed on the device sensitive layer 200, there will be no polymer residue or only a small amount of polymer residue between the passivation protection layer 400 and the device sensitive layer 200, so that it is difficult to form a hole or a step. Figure 7 , Figure 7 The film layer inside the sensitive device structure shown is uniform and good, and no voids are generated.

[0060] Therefore, this embodiment can effectively reduce polymer residues, thereby effectively improving the electrical properties and reliability of the product terminal.

[0061] In one embodiment, the first etching gas further includes an etching inhibition gas. The etching inhibition gas is used to inhibit the reaction etching rate of the first fluoride gas. The volume proportion of the etching inhibition gas in the first etching gas does not exceed 5% of the volume proportion of the first fluoride gas.

[0062] Since the fluoride gas has a very fast reaction etching rate, the sidewall protection gas may have insufficient control over the shape of the device sensitive layer 200 , thereby causing poor control over the shape of the device sensitive layer 200 .

[0063] Therefore, in this embodiment, an etching inhibition gas is also added to the first etching gas, so that the shape of the device sensitive layer 200 can be well controlled while ensuring the reduction of polymer residues. At the same time, the volume proportion of the etching inhibition gas does not exceed 5% of the volume proportion of the first fluoride gas, which can ensure that the fluoride gas has a sufficient reaction etching rate.

[0064] As an example, the first fluoride gas may include sulfur fluoride (SF 6 ) gas, the sidewall protection gas may include boron chloride (BCl 3 ) gas. The etching inhibition gas may include oxygen (O 2 Boron chloride (BCl 3 ) gas and oxygen (O 2 ) can have the same gas volume ratio. The gas volume ratios of the two gases can both be 5% of the volume ratio of the first fluoride gas.

[0065] Sulfur fluoride (SF 6 ) gas can react quickly and fully with the sensitive material layer 201 of materials such as vanadium oxide. Boron chloride (BCl 3 ) gas can undergo polymerization reaction in high-energy etching environment to generate B chain, which can form a sidewall protection layer. 2 ) has strong oxidizing properties, which can inhibit sulfur fluoride (SF 6 ) The reaction etching rate of gas with vanadium oxide, etc.

[0066] Of course, the sidewall protection gas may also include other gases (such as carbon-containing gases, etc.). The etching inhibition gas may also include other gases (such as nitrogen, which also has strong oxidizing properties, so nitrogen can also inhibit sulfur fluoride (SF 6 ) The reaction etching rate of gas with vanadium oxide, etc.).

[0067] In one embodiment, before step S400, the method further includes:

[0068] Step S300, pre-etching the sensitive material layer 201 based on the patterned mask layer 300 under the second etching gas to form a pre-etched sidewall inclined outward in the sensitive material layer 201, see Figure 3 .

[0069] Specifically, the second etching gas may include a second fluoride gas, and the volume proportion of the second fluoride gas in the second etching gas may be 70%-85%.

[0070] By using the second etching gas with a volume proportion of 70%-85% of the second fluoride gas for pre-etching, that is, using a relatively low content of fluoride gas, the sensitive material layer 201 can form a pre-etched sidewall inclined outward under the shielding of the patterned mask 300. It can be understood that the "inclined outward" here refers to the side away from the shielding of the patterned mask 300.

[0071] In this embodiment, the pre-etching process can be performed to ensure that the device sensitive layer 200 formed subsequently (see Figure 4 ) is inclined outward at a portion (referred to as the first sidewall portion 210) close to the patterned mask 300, so that the angle between this portion of the sidewall and the upper surface of the device sensitive layer 200 is an obtuse angle, thereby making the sidewall of the device sensitive layer 200 gradually steeper, so that the deposition surface of the subsequently formed passivation protection layer 400 is more rounded and smooth, thereby effectively improving the deposition quality of the subsequently formed passivation protection layer 400.

[0072] It can be understood here that the first sidewall portion 210 is a sidewall formed under the combined action of the pre-etching and the main etching, and the second sidewall portion 220 is a sidewall formed under the action of the main etching alone.

[0073] Furthermore, after this embodiment, when the main etching is performed, the volume ratio of the first fluoride gas can be adjusted so that the second side wall portion 220 is also tilted outward, so that the deposition surface of the subsequently formed passivation protection layer 400 is smoother, thereby more effectively improving the deposition quality of the subsequently formed passivation protection layer 400.

[0074] In one embodiment, the second etching gas includes a sensitive layer etching gas and a mask layer etching gas. The sensitive layer etching gas is used to pre-etch the sensitive material layer 201 , and the mask layer etching gas is used to etch the patterned mask layer 300 .

[0075] As an example, the sensitive layer etching gas may include a second fluoride gas. Specifically, the second fluoride gas may include sulfur fluoride gas. The mask layer etching gas may include oxygen. The volume proportion of the second fluoride gas in the second etching gas may be 70%-85%, and the volume proportion of the mask layer etching gas in the second etching gas may be 15%-30%. At the same time, the patterned mask layer 300 may include a patterned photoresist layer. At this time, the oxygen may etch the patterned photoresist layer.

[0076] At this time, the second etching gas etches the patterned mask layer 300 while pre-etching the sensitive material layer 201, so that the side of the patterned mask layer forms an inclined sidewall (such as a curved gently sloping sidewall). Specifically, no electric field may be provided at this time, so that the etching intensity of the plasma in the vertical direction is equal to the etching intensity in the horizontal direction, so as to facilitate isotropic etching, thereby facilitating the formation of the inclined sidewall. After removing the corners of the patterned mask layer 300 away from the sensitive material layer 201, the sidewall of the patterned mask layer 300 also tilts outwards. Since the thickness of the inclined sidewall is different at different positions, it has different etching blocking effects; therefore, at this time, it is helpful to form an outwardly inclined pre-etched sidewall when pre-etching the sensitive material layer 201, which is beneficial to the subsequent main etching to form a device sensitive layer 200 with an outwardly inclined sidewall, and is beneficial to the deposition of the passivation protection layer 400.

[0077] As an example, see Figure 8 , Figure 8 The structure scan before removing the patterned photoresist (patterned mask layer 300) is shown. It can be seen that after the main etching, the side wall of the patterned photoresist forms an angle of 88.87 degrees with the bottom surface, while the side wall (specifically the second side wall portion 220) of the vanadium oxide layer (device sensitive layer 200) forms an angle of 86.48 degrees with the bottom surface and tilts outward.

[0078] In one embodiment, the angle between the sidewall of the patterned mask layer 300 and its bottom surface is a right angle or an acute angle, thereby facilitating the formation of the device sensitive layer 200 with outwardly inclined sidewalls.

[0079] When the angle between the sidewall and the bottom surface of the patterned mask layer 300 is an acute angle, before etching the sensitive material layer 201, the patterned mask layer 300 has a sidewall that is inclined outward. The thickness of the inclined sidewall is different at different positions, thereby having different etching blocking effects. Therefore, this embodiment can be more conducive to forming an outwardly inclined etching sidewall when etching the sensitive material layer 201, that is, it is more conducive to forming a device sensitive layer 200 with an outwardly inclined sidewall.

[0080] Specifically, the patterned mask layer 300 may include a patterned photoresist layer, and the angle between the sidewall and the bottom surface thereof may be controlled by a photolithography process.

[0081] In one embodiment, the main etching and the pre-etching are performed in the same etching chamber, which simplifies the process and prevents the product from being contaminated due to the replacement of the etching chamber.

[0082] At the same time, during the pre-etching and the main etching, the vacuum degree in the etching chamber is lower than 10mTorr and the etching power is lower than 500w, so that the etching process is controllable.

[0083] Specifically, the same vacuum degree and etching power can be used when performing pre-etching and main etching. In the process of changing from pre-etching to main etching, only the etching gas can be changed. More specifically, when performing pre-etching and main etching, the second etching gas and the first etching gas can include the same type of gas (such as sulfur fluoride and oxygen), and then in the process of changing from pre-etching to main etching, the gas volume ratio is changed and new etching gas is added as needed.

[0084] In one embodiment, step S300 includes:

[0085] Step S310, dry etching the patterned mask layer 300 at a preset temperature, the preset temperature being less than 200° C.;

[0086] Step S320 , removing the patterned mask layer 300 by using a wet solution.

[0087] The patterned mask layer 300 can be effectively removed by combining the wet method with the dry method. At the same time, dry etching at a preset temperature can also prevent the device structure from being damaged during the process of removing the patterned mask layer 300.

[0088] Specifically, the preset temperature can be, for example, a temperature less than 200°C. More specifically, the preset temperature can be between 150°C and 190°C. When the temperature is too high, the resistance of vanadium oxide increases with the increase in temperature, which can easily cause the device to fail. When the temperature is too low, the speed of dry etching to remove the patterned mask layer 300 is too slow, which will affect the process efficiency. Therefore, the temperature can be set between 150°C and 190°C to dry-etch the patterned mask layer 300, thereby preventing the vanadium oxide resistance from being too large and causing device failure, and ensuring the process efficiency.

[0089] In one embodiment, a sensitive device structure is further provided, which is formed according to any of the above methods.

[0090] In one embodiment, a sensitive device is further provided, comprising a sensitive device structure formed according to any one of the above methods.

[0091] Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0092] In the description of this specification, the description of reference terms such as "one embodiment" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0093] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing a sensitive device structure, characterized in that: include: forming a sensitive material layer and a patterned mask layer on the substrate in sequence; Under a first etching gas, the sensitive material layer is mainly etched based on the patterned mask layer to form a device sensitive layer, wherein the first etching gas includes a first fluoride gas and a sidewall protection gas, and the volume proportion of the sidewall protection gas in the first etching gas does not exceed 5% of the volume proportion of the first fluoride gas. During the etching process, the sidewall protection gas decomposes in the high-energy etching environment and undergoes a polymerization reaction to form a protective film layer on the sidewall surface; removing the patterned mask layer; A passivation protection layer is formed on the device sensitive layer.

2. The method for preparing a sensitive device structure according to claim 1, characterized in that: The first etching gas also includes an etching inhibition gas, which is used to inhibit the reaction etching rate of the first fluoride gas. The volume proportion of the etching inhibition gas in the first etching gas does not exceed 5% of the volume proportion of the first fluoride gas.

3. The method for preparing a sensitive device structure according to claim 2, characterized in that: The etch inhibiting gas includes oxygen.

4. The method for preparing a sensitive device structure according to any one of claims 1 to 3, characterized in that: Before the main etching of the sensitive material layer based on the patterned mask layer under the first etching gas, the method further includes: Under the second etching gas, the sensitive material layer is pre-etched based on the patterned mask layer to form a pre-etched sidewall inclined outward in the sensitive material layer.

5. The method for preparing a sensitive device structure according to claim 4, characterized in that: The second etching gas includes a sensitive layer etching gas and a mask layer etching gas, the sensitive layer etching gas is used for pre-etching the sensitive material layer, and the mask layer etching gas is used for etching the patterned mask layer.

6. The method for preparing a sensitive device structure according to claim 5, characterized in that: The sensitive layer etching gas includes a second fluoride gas, and the volume proportion of the second fluoride gas in the second etching gas is 70%-85%.

7. The method for preparing a sensitive device structure according to claim 4, characterized in that: The main etching and the pre-etching are performed in the same etching chamber. When performing the pre-etching and the main etching, the vacuum degree in the etching chamber is lower than 10 mTorr and the etching power is lower than 500 W.

8. The method for preparing a sensitive device structure according to claim 1, characterized in that: The removing of the patterned mask layer comprises: Dry etching the patterned mask layer at a preset temperature, wherein the preset temperature is less than 200° C.; The patterned mask layer is removed by a wet solution.

9. A sensitive device structure, characterized in that: Formed according to the method according to any one of claims 1 to 8.

10. A semiconductor device, characterized in that: The invention comprises a sensitive device structure formed by the method according to any one of claims 1 to 8.

Images