Semiconductor processing method and semiconductor device

Abstract

A semiconductor processing method and a semiconductor device, the semiconductor processing method comprising: forming an intermediate structure comprising a substrate, a metal structure, and a patterned mask layer; placing the intermediate structure in an etching chamber of an etching machine, and performing an etching process on the metal structure in the etching chamber using an etching material, the etching process using the patterned mask layer as an etching mask, removing portions of the metal structure, and forming a metal pattern; after the etching process, a residue of an etching byproduct generated from a reaction of the etching material and the removed portions of the metal structure remains on a surface of the intermediate structure; moving the intermediate structure from the etching chamber of the etching machine to an additional vacuum chamber of the etching machine, introducing water vapor into the additional vacuum chamber, and dissociating the water vapor into a plasma, wherein the plasma reacts with the etching byproduct and generates a gaseous product; and evacuating the gaseous product from the additional vacuum chamber using a vacuum pump.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the field of semiconductor technology, and in particular, to a semiconductor processing method and a semiconductor device. BACKGROUND

[0002] In a semiconductor process, an etching process is a common removal process and an important step in a patterning process. Generally, in an etching process, an etching substance such as an etchant or an etching gas reacts with a material to be etched on a target structure to remove the material to be etched; however, the etching byproduct generated by the reaction of the etchant or the etching gas with the material to be etched can be attached to the target structure, and such etching byproduct can adversely affect the reliability of the target structure and the performance of the semiconductor device ultimately formed. SUMMARY

[0003] According to at least one embodiment of the present disclosure, a semiconductor processing method is provided, including: forming an intermediate structure, wherein the intermediate structure includes a substrate, a metal structure, and a patterned mask layer, the metal structure is located on one side of the substrate, and the patterned mask layer is located on a side of the metal structure away from the substrate; placing the intermediate structure in an etching chamber of an etching machine, and performing an etching process on the metal structure in the etching chamber using an etching substance, the etching process uses the patterned mask layer as an etching mask to remove part of the metal structure and form a metal pattern; wherein after the etching process, an etching byproduct generated by the reaction of the etching substance and the removed part of the metal structure remains on the surface of the intermediate structure; transferring the intermediate structure from the etching chamber of the etching machine to an additional vacuum chamber of the etching machine, introducing water vapor into the additional vacuum chamber, and dissociating the water vapor into plasma, wherein the plasma reacts with the etching byproduct and generates a gaseous product; and using a vacuum pump to pump out the gaseous product from the additional vacuum chamber.

[0004] In the semiconductor processing method according to at least one embodiment of the present disclosure, the process of transferring the intermediate structure from the etching chamber to the additional vacuum chamber is located in the etching machine, which is isolated from the atmosphere and in a vacuum environment.

[0005] In the semiconductor processing method according to at least one embodiment of the present disclosure, in the etching chamber, the surface of the metal pattern away from the substrate is covered by the patterned mask layer, and the etching byproduct is attached to the side surface of the patterned mask layer, the surface of the patterned mask layer away from the substrate, and the side surface of the metal pattern.

[0006] According to at least one of the embodiments of the present disclosure, the reaction between the plasma and the etching byproducts further generates metal oxides, a portion of which is on the side surface of the metal pattern and another portion of which is on the surface of the patterned mask layer.

[0007] According to at least one of the embodiments of the present disclosure, the semiconductor processing method further includes: removing the patterned mask layer and the another portion of the metal oxides on the patterned mask layer after the intermediate structure is removed from the etching machine, and exposing the surface of the metal pattern away from the substrate.

[0008] According to at least one of the embodiments of the present disclosure, the semiconductor processing method further includes: naturally oxidizing the surface of the metal pattern away from the substrate and forming a natural oxide layer after the patterned mask layer is removed.

[0009] According to at least one of the embodiments of the present disclosure, the metal structure is a single-layer structure or a multi-layer structure.

[0010] According to at least one of the embodiments of the present disclosure, the metal structure includes a first metal layer and a second metal layer having different materials, and the etching byproducts include a first byproduct generated by the reaction between the etching substance and the first metal layer and a second byproduct generated by the reaction between the etching substance and the second metal layer.

[0011] According to at least one of the embodiments of the present disclosure, the gaseous byproducts include a byproduct generated by the reaction between the plasma and the first byproduct and a byproduct generated by the reaction between the plasma and the second byproduct.

[0012] According to at least one of the embodiments of the present disclosure, the first metal layer includes aluminum or aluminum-copper alloy, the second metal layer includes titanium, and the second metal layer is disposed on the side of the first metal layer away from the substrate.

[0013] According to at least one of the embodiments of the present disclosure, the water vapor is dissociated into the plasma under the action of microwaves.

[0014] According to at least one of the embodiments of the present disclosure, the material of the metal structure includes metal or metal alloy, and the etching substance includes halogen-containing gas.

[0015] According to at least one embodiment of the present disclosure, the material of the metal structure is selected from at least one of aluminum, aluminum-copper alloy, titanium, iron, copper, zinc, magnesium, manganese, and cobalt.

[0016] According to at least one embodiment of the present disclosure, the etching substance is an etching gas, and includes chlorine gas or a chlorine-containing compound, the etching byproduct includes a chlorine-containing metal salt, and the gaseous product generated by the reaction of the plasma and the etching byproduct includes hydrogen chloride gas.

[0017] According to at least one embodiment of the present disclosure, a semiconductor device includes a substrate and a metal pattern on the substrate, the metal pattern including at least one of one or more metal electrodes and metal wires, and is formed by the semiconductor processing method of any one of the above.

[0018] According to at least one embodiment of the present disclosure, the semiconductor device includes a micro-electro-mechanical system device or a complementary metal-oxide-semiconductor device.

[0019] According to at least one embodiment of the present disclosure, the semiconductor device includes a filter. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only related to some embodiments of the present disclosure and are not limiting of the present disclosure.

[0021] Figure 1 A schematic cross-sectional view showing an intermediate structure formed in a method of manufacturing a semiconductor device according to some embodiments of the present disclosure, wherein the intermediate structure includes a substrate, a metal structure, and a patterned mask layer.

[0022] Figure 2 A schematic cross-sectional view showing an etching process on the metal structure of an intermediate structure to form a metal pattern in a method of manufacturing a semiconductor device according to some embodiments of the present disclosure, wherein an etching byproduct remains on the surface of the intermediate structure.

[0023] Figure 3 A schematic cross-sectional view showing a water vapor plasma treatment on the intermediate structure to remove the etching byproduct in a method of manufacturing a semiconductor device according to some embodiments of the present disclosure.

[0024] Figure 4 A schematic cross-sectional view showing a removal of the patterned mask layer of an intermediate structure in a method of manufacturing a semiconductor device according to some embodiments of the present disclosure.

[0025] Figure 5A schematic cross-sectional view showing a metal pattern of an intermediate structure in a method of manufacturing a semiconductor device according to some embodiments of the present disclosure is naturally oxidized.

[0026] Figure 6 A schematic block diagram showing an etching machine according to some embodiments of the present disclosure.

[0027] Figure 7 A picture showing a metal electrode with post-etching corrosion.

[0028] Figure 8 A picture showing a metal electrode with patterned abnormality.

[0029] Figure 9 A picture showing a surface of an intermediate structure exposed to an atmospheric environment according to experimental examples of the present disclosure.

[0030] Figure 10 A picture showing a surface of an intermediate structure after being placed in an atmospheric environment for 24 hours according to embodiments of the present disclosure.

[0031] Figure 11 A picture showing a surface of an intermediate structure after being placed in an atmospheric environment for 72 hours according to embodiments of the present disclosure.

[0032] Figure 12 A picture showing a surface of an intermediate structure after a patterned mask layer is removed according to embodiments of the present disclosure.

[0033] Figure 13 A schematic flow chart showing a semiconductor processing method according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some but not all of the embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present disclosure.

[0035] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the meanings as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first", "second", and similar terms are used herein to distinguish one element from another, and are not necessarily used in a sequence or to denote importance or quantity. The terms "comprises", "comprising", "includes", "including" and the like can be used herein to indicate that elements or objects encompassed by the terms can be included or can not be included. The terms "connected", "coupled", and the like can be used herein to indicate either a direct connection or an indirect connection or an electrical connection, whether or not it is a physical or mechanical connection.

[0036] Metal materials are widely used in electronic devices such as semiconductor devices to form important components such as electrodes and wires. For example, in micro-electro-mechanical system (MEMS) devices or other types of semiconductor devices such as filters, metal materials are commonly used as electrode plate materials or as conductor materials for wires, including but not limited to metals such as aluminum (Al), titanium (Ti), iron (Fe), copper (Cu), zinc (Zn), magnesium (Mg), manganese (Mn), cobalt (Co), and metal alloys such as aluminum-copper (AlCu) or combinations thereof.

[0037] For example, in a wafer-level process, a metal material layer is first formed on a wafer surface, and then the metal material layer is patterned by a patterning process including photolithography and etching to define a metal pattern. For example, the photolithography process includes forming a patterned photoresist (PR) layer on the metal material layer, and then using the patterned photoresist layer as an etching mask for an etching process on the metal material layer to remove portions of the metal material layer and form the metal pattern. For example, the etching process can include introducing etching gases such as chlorine (Cl2) and / or boron trichloride (BCl3) into an etching chamber, which react with the metal material to be removed to remove portions of the metal material layer. Most of the etching byproducts generated by the reaction of the etching gases and the metal material are pumped out by a vacuum pump of the etching chamber, but some of the etching byproducts can adhere to the surfaces of the photoresist and the metal pattern. The etching byproducts can include metal salts; for example, in the case where the etching gases include chlorine and / or boron trichloride, the etching byproducts can include chlorine-containing metal salts (e.g., metal chlorides) and chlorine gas complexes.

[0038] After the etching process, the wafer with the metal pattern and the photoresist is transferred to another process machine for further processing. However, when exposed to the air, the etching byproducts (e.g., chlorine-containing metal salt) on the surface of the metal pattern and / or the photoresist can react with the water vapor in the air to form an acid solution, such as hydrochloric acid (i.e., HCl aqueous solution), which can corrode the metal pattern and cause damage to the metal pattern, and even cause the metal pattern to be broken off and the device to fail. Figure 7 The corroded area 11 of the metal pattern 10 is shown schematically. The area 11 is corroded by the acid solution formed by the reaction between the etching byproducts on the surface of the metal pattern and the water vapor after the etching process. In some examples, the corrosion of the metal pattern caused by the etching byproducts is referred to as post-etching corrosion.

[0039] In some examples, the time for the metal pattern to be exposed to the air before being transferred to the next process equipment (e.g., a photoresist removal equipment) can be reduced by manual control to reduce the degree of corrosion of the metal pattern. However, this method cannot completely solve the corrosion problem. In addition, there can be a problem of control failure in manual control. For example, due to the failure of the next process equipment, insufficient production capacity of the equipment, or a long interval between the first wafer and the last wafer in the operation of a single photoresist removal equipment, some wafers can be exposed to the air for too long, which can cause the metal pattern to be corroded.

[0040] In other examples, a water washing and drying step can be added after the etching process to clean the etching byproducts attached to the surface of the wafer after the etching process, thereby reducing the risk of post-etching corrosion. However, the equipment for the water washing and drying step is different from the etching machine, that is, different equipment needs to be switched between the etching process step and the water washing and drying step. Therefore, the wafer is still exposed to the air during the transfer between different equipment, and there is still a risk of post-etching corrosion of the metal. For example, if the operation is delayed during the switching of the equipment, the metal pattern can be corroded.

[0041] In yet some examples, to avoid the risk of post-etching corrosion caused by the device switching process, after the etching process, the photoresist and the etching byproducts can be removed in a different chamber of the same etching machine using oxygen (O2), so as to avoid the post-etching corrosion of the wafer when it is moved out of the etching machine to the atmospheric environment. However, if the metal pattern includes titanium metal, the titanium metal will react with oxygen to generate titanium oxide (Ti2O3), so that after the photoresist is removed, the top surface of the titanium metal will also be oxidized; and in this case, different regions of the titanium metal surface can be oxidized to different degrees, i.e., the titanium oxide can be unevenly distributed on the titanium metal surface, which may, for example, cause a patterned abnormal region on the surface of the metal pattern, affecting the appearance quality and reliability of the metal pattern, etc. Figure 8 An illustrative patterned abnormal region 12 on the surface of a metal pattern 10 including titanium is shown in the above case.

[0042] To solve the above problems, the semiconductor processing method provided by the embodiments of the present disclosure can effectively avoid the post-etching corrosion of the metal pattern caused by the etching byproducts after the etching process, and can make the formed metal pattern have better appearance quality, improve the reliability of the metal pattern, and improve the performance of the formed device.

[0043] For example, the semiconductor processing method provided by the embodiments of the present disclosure includes: forming an intermediate structure, wherein the intermediate structure includes a substrate, a metal structure, and a patterned mask layer, the metal structure is located on one side of the substrate, and the patterned mask layer is located on the side of the metal structure away from the substrate; placing the intermediate structure in an etching chamber of an etching machine, and using an etching substance in the etching chamber to perform an etching process on the metal structure, the etching process uses the patterned mask layer as an etching mask, removes part of the metal structure, and forms a metal pattern; wherein after the etching process, etching byproducts generated by the reaction of the etching substance and the removed part of the metal structure remain on the surface of the intermediate structure; moving the intermediate structure from the etching chamber of the etching machine to an additional vacuum chamber of the etching machine, introducing water vapor into the additional vacuum chamber, and dissociating the water vapor into plasma, wherein the plasma reacts with the etching byproducts and generates gaseous products; and using a vacuum pump to extract the gaseous products from the additional vacuum chamber.

[0044] In the embodiments of the present disclosure, after the etching reaction is performed in the etching chamber of the etching machine, the reaction with water vapor plasma and etching byproducts is performed in the additional vacuum chamber of the same etching machine, so that the etching byproducts of the intermediate structure can be prevented from contacting the atmosphere before being removed, and the surface of the intermediate structure can be substantially free of the etching byproducts when the intermediate structure is subsequently transferred to the atmosphere outside the etching machine; thus, the etching byproducts can be prevented from reacting with water vapor in the air to produce an acid solution to corrode the metal pattern, the appearance quality of the metal pattern is improved, and the reliability and performance of the metal pattern and the semiconductor device including the same are improved.

[0045] Figures 1 to 5 Fig. 1 shows a schematic cross-sectional view of an intermediate structure in a step of a method of manufacturing a semiconductor device according to some embodiments of the present disclosure, which schematically shows an operating step of a semiconductor processing method. Figure 6 Fig. 2 shows a schematic block diagram of an etching machine. Figure 13 Fig. 3 shows a schematic flowchart of a semiconductor processing method according to some embodiments of the present disclosure.

[0046] Reference Figure 13 In some embodiments, in a first step S1, an intermediate structure is formed, wherein the intermediate structure includes a substrate, a metal structure, and a patterned mask layer. For example, as shown in Fig. 1, an intermediate structure 120 is formed; for example, the intermediate structure 120 includes a substrate 100, a metal structure 103, and a patterned mask layer 105. The substrate 100 can be or include a semiconductor substrate, such as a silicon substrate. The metal structure 103 is formed on one side of the substrate 100, and can include a metal such as aluminum, titanium, iron, copper, zinc, magnesium, manganese, cobalt, etc., a metal alloy such as aluminum copper, or a combination thereof. In some embodiments, the metal structure 103 is directly formed on the substrate 100 and in contact with the substrate 100; in alternative embodiments, other material layers (not shown) can also be formed between the substrate 100 and the metal structure 103, i.e., the metal structure 103 is formed above the substrate 100 and is not in direct contact with the substrate 100. Figure 1

[0047] The patterned mask layer 105 is disposed on the side of the metal structure 103 away from the substrate 100, and is used to define a metal pattern in subsequent processes. For example, the patterned mask layer 105 can be or include a patterned photoresist layer, and can be formed by forming a photoresist layer on the metal structure 103, and then patterning the photoresist layer by a photolithography process. The photolithography process includes an exposure and development process.

[0048] For example, the patterned mask layer 105 has an opening 106 that exposes the surface of the portion of the metal structure 103 to be removed. It should be understood that the mask pattern shown in the figure is only illustrative, and the present disclosure is not limited thereto. ​

[0049] In some embodiments, the intermediate structure 120 can be a wafer structure, i.e., the substrate 100 is a wafer, such as a semiconductor wafer, e.g., a silicon wafer. For example, the substrate 100 has a plurality of chip regions and a plurality of dicing regions; the plurality of chip regions are arranged apart from each other, e.g., in an array; the plurality of chip regions are separated from each other by the plurality of dicing regions. For example, Figure 1 The metal structure 103 and the patterned mask layer 105 are shown in a chip region.

[0050] Referring to Figure 1 , Figure 2 and Figure 13 , in a second step S2, an etching process is performed on the metal structure in an etching chamber of an etching machine. For example, the metal structure 103 is etched using the patterned mask layer 105 as an etching mask to remove portions of the metal structure 103 exposed by the patterned mask layer 105 and form a metal pattern 103a. For example, the etching process can be performed in the etching machine.

[0051] Figure 6 A schematic block diagram of an etching machine 200 according to some embodiments of the present disclosure is shown.

[0052] Referring to Figure 6 In some embodiments, the etching machine 200 includes an etching chamber 201 and an additional vacuum chamber 202; it should be understood that in the etching machine 200, the etching chamber 201 and the additional vacuum chamber 202 and the space between the chambers are all isolated from the atmospheric environment, e.g., can all be substantially in a vacuum environment. For example, the etching chamber 201 can be used to perform an etching process, and the additional vacuum chamber 202 can be used to perform a removal process of etching byproducts.

[0053] Referring to Figure 1 , Figure 2 and Figure 6 In some embodiments, the etching process of the metal structure 103 can include the following steps: placing Figure 1 The intermediate structure 120 is shown in the etching chamber 201 of the etching machine 200, and an etching substance is used in the etching chamber 201 to perform an etching process on the metal structure 103, the etching process using the patterned mask layer 105 as an etching mask to remove portions of the metal structure 103 and form a metal pattern 103a. For example, the etching substance is used in the etching chamber 201 to perform an etching process on the metal structure 103 includes introducing an etching gas into the etching chamber 201 to etch the metal structure.

[0054] After the etching process, etching byproducts generated from the reaction between the etching material (e.g., etching gas) and the removed portions of the metal structure 103 remain on the surface of the intermediate structure 120. For example, most of the etching byproducts generated from the reaction between the etching gas and the metal structure 103 can be pumped out of the etching chamber by the vacuum pump, but some of the etching byproducts can adhere to the surface of the patterned mask layer 105 and the metal pattern 103a of the intermediate structure, e.g., a byproduct layer 107 can be formed on the surface of the intermediate structure. It should be understood that Figure 2 The byproduct layer 107 in FIG. 1 is schematically shown as the etching byproducts adhering to the intermediate structure, but it can be continuous or discontinuous, and the distribution area and size of the etching byproducts are not limited to Figure 2 those shown in FIG. 1.

[0055] In some embodiments, in the etching chamber, the surface of the metal pattern away from the substrate is covered by the patterned mask layer, and the etching byproducts adhere to the side surface of the patterned mask layer and the surface thereof away from the substrate, and to the side surface of the metal pattern.

[0056] Referring to Figure 2 , for example, after the etching process in the etching chamber, the surface of the metal pattern 103a away from the substrate 100 is covered by the patterned mask layer 105, e.g., completely covered. Therefore, the surface of the metal pattern 103a away from the substrate is not in contact with the etching byproducts. The etching byproducts can adhere to the side surface of the patterned mask layer 105 and the surface thereof away from the substrate 100, and to the side surface of the metal pattern 103a.

[0057] In some embodiments, the material of the metal structure includes a metal or a metal alloy, and the etching material used in the etching process includes an etching gas containing a halogen, e.g., an etching gas including chlorine and / or a chlorine-containing compound. In some examples, the etching gas includes chlorine and boron trichloride, and can be dissociated into chloride ions (Cl - ) in the etching process; for example, the etching gas is introduced into the etching chamber with chlorine and boron trichloride gas, and the etching gas is dissociated into a plasma including chloride ions by radio frequency (RF). For example, the equation for the dissociation of chlorine to generate chloride ions is as follows:

[0058]

[0059] The boron trichloride can dissociate to generate chloride ions and can promote the dissociation of chlorine, and the relevant equation is as follows:

[0060]

[0061] In some embodiments, the etching byproducts generated by the reaction between the metal structure and the etching gas include metal salts; for example, when the etching gas includes a chlorine-containing gas, the metal salts include chlorine-containing metal salts.

[0062] For example, the material of the metal structure 103 can be selected from at least one of metals such as aluminum, titanium, iron, copper, zinc, magnesium, manganese, and cobalt, as well as metal alloys such as aluminum-copper alloys. The chemical equation for the reaction between the above materials and the chloride ions generated by the dissociation of the chloride-containing etching gas is shown below:

[0063]

[0064] When the metal structure comprises multiple metal materials, the byproducts generated by the etching reaction include a mixture of etching byproducts generated by the reaction of each of the multiple metal materials with the etching gas.

[0065] Next, the etching byproducts adhering to the intermediate structure are treated to remove them. In some embodiments, the intermediate structure is moved from the etching chamber of the etching apparatus to an auxiliary vacuum chamber of the etching apparatus, water vapor is introduced into the auxiliary vacuum chamber, and the water vapor is dissociated into plasma, wherein the plasma reacts with the etching byproducts to generate gaseous products; then, the gaseous products are extracted from the auxiliary vacuum chamber using a vacuum pump. In some embodiments, the entire process of transferring the intermediate structure from the etching chamber to the auxiliary vacuum chamber takes place within the etching apparatus, isolated from the atmospheric environment, and under vacuum.

[0066] For example, refer to Figure 13 In the third step S3, the intermediate structure is moved from the etching chamber of the etching machine to the additional vacuum chamber in the same etching machine; in the fourth step S4, water vapor plasma is used in the additional vacuum chamber to treat the residual etching byproducts on the intermediate structure.

[0067] For example, refer to Figure 2 , Figure 3 and Figure 6 The etching byproducts adhering to the intermediate structure 120 are treated to remove them. For example, after the etching process, the etching byproducts are removed. Figure 2 The intermediate structure 120 shown is moved from the etching chamber 201 of the etching machine 200 to the auxiliary vacuum chamber 202 of the etching machine 200 for the treatment of etching byproducts. For example, after the etching process, the intermediate structure 120 is removed from the etching machine 200 and transferred to the auxiliary vacuum chamber 202 through a vacuum transfer channel.

[0068] After moving the intermediate structure 120 to the additional vacuum chamber 202, water vapor (i.e., H2O gas) is introduced into the additional vacuum chamber 202 and dissociated into plasma. For example, the water vapor can be dissociated into plasma under the action of microwaves; the plasma can include hydrogen ions and oxygen ions. The plasma reacts with the etching byproducts (e.g., MnO, MnO2, Mn2O3) attached to the intermediate structure 120 (e.g., the byproduct layer 107 shown in FIG. 1) to remove the etching byproducts from the surface of the intermediate structure 120. For example, the plasma reacts with the etching byproducts to generate gaseous products. The gaseous products can be pumped out of the additional vacuum chamber 202 by a vacuum pump of the additional vacuum chamber. Figure 2

[0069] The etching chamber 201 and the additional vacuum chamber 202 are located in the same etching machine 200; for example, the etching chamber 201, the additional vacuum chamber 202, and the transfer passage between the etching chamber 201 and the additional vacuum chamber 202 are all in a vacuum environment. Therefore, the intermediate structure 120 is not exposed to the atmosphere during etching, generation of etching byproducts, and treatment of the etching byproducts in the etching chamber and the additional vacuum chamber of the etching machine and during transfer between the etching chamber and the additional vacuum chamber. That is, etching of the intermediate structure 120, generation of etching byproducts, and treatment of the etching byproducts are all carried out in a vacuum environment, i.e., are not exposed to the atmosphere; thus, the etching byproducts are prevented from contacting water vapor in the atmosphere, thereby avoiding the problem of corrosion of the metal pattern after etching caused by the etching byproducts.

[0070] In some embodiments, the etching byproducts are metal salts, e.g., include metal salts containing chlorine; and the gaseous products generated by the reaction of the water vapor plasma and the etching byproducts can be or include hydrogen chloride gas. At this time, since the hydrogen chloride is in a gaseous state, it is less likely (e.g., substantially not) to react with the surface of the metal pattern, and the generated gaseous products are pumped out in time by the vacuum pump, so the gaseous products (e.g., hydrogen chloride gas) substantially do not cause corrosion of the metal pattern.

[0071] In some embodiments, the plasma and the etching byproducts also generate metal oxides, part of which can be located on the side surface of the metal pattern, and another part of which can be located on the surface of the patterned mask layer.

[0072] For example, the chemical equation for the reaction of the etching byproducts generated by the reaction of the metal material and the etching gas with water vapor is as follows:

[0073]

[0074] In the above equation, Mn x O y may include at least one of MnO, MnO2, and Mn2O3. ​

[0075] For example, as shown in Figure 2 and Figure 3 In the additional vacuum chamber, the etching byproduct layer 107 is removed by reacting with water vapor plasma, and a metal oxide layer 108 is formed on the surface of the intermediate structure 120. Figure 3 The morphology of the formed metal oxide is schematically shown, but the present disclosure is not limited thereto. The metal oxide formed on the surface of the intermediate structure 120 can be continuous or discontinuous.

[0076] In the process of removing the etching byproduct in the additional vacuum chamber, the surface of the metal pattern 103a away from the substrate 100 is covered by the patterned mask layer 105, so the surface of the metal pattern 103a is not oxidized by the oxygen ions in the plasma. In some examples, the side surface of the metal pattern 103a is covered by the metal oxide layer 108, so it is also not oxidized.

[0077] In some embodiments, after removing the etching byproduct in the additional vacuum chamber of the etching machine, the intermediate structure is removed from the etching machine, and then the patterned mask layer and the metal oxide on the patterned mask layer are removed, and the surface of the metal pattern away from the substrate is exposed. In some embodiments, after removing the patterned mask layer, natural oxidation occurs on the surface of the metal pattern away from the substrate and forms a natural oxidation layer.

[0078] For example, referring to Figure 13 In the fifth step S5, the intermediate structure is removed from the etching machine, and then the patterned mask layer is removed.

[0079] For example, referring to Figure 3 and Figure 4 The patterned mask layer 105 is removed. For example, after completing the removal of the etching byproduct in the additional vacuum chamber 202 of the etching machine 200, the intermediate structure 120 is removed from the etching machine 200 and transferred to the next process to remove the patterned mask layer 105 and the metal oxide on the surface of the patterned mask layer 105.

[0080] For example, when the patterned mask layer 105 comprises photoresist, the intermediate structure 120 can be transferred to a stripping apparatus to remove the patterned mask layer 105 and a portion of the metal oxide layer 108 on the surface thereof, and to expose the surface of the metal pattern 103a on the side distal to the substrate 100. Before the intermediate structure 120 is removed from the etching machine 200 and transferred to the next process, the intermediate structure 120 can be exposed to the atmosphere; in this case, since the etching byproducts (e.g., chlorine-containing metal salts) on the surface of the intermediate structure 120 have been removed in the etching machine, post-etching corrosion of the metal pattern of the intermediate structure 120 in the atmosphere due to the etching byproducts can be avoided.

[0081] Reference Figures 4 to 5 In some embodiments, after the patterned mask layer 105 is removed, the metal pattern 103a can be naturally oxidized in the atmosphere, and a natural oxide layer 109 can be formed on the surface of the metal pattern 103a distal to the substrate 100. For example, the surface of the metal pattern 103a distal to the substrate 100 comprises titanium metal material, and the titanium metal is naturally oxidized in the atmosphere, and a layer of titanium oxide is formed on the surface thereof. The natural oxide layer 109 can protect the metal pattern 103a. In general, the natural oxide layer formed by natural oxidation of the metal surface has a uniform thickness, i.e., is uniformly distributed on the surface of the metal pattern, and thus does not substantially affect the appearance quality and reliability of the metal pattern.

[0082] In some embodiments, the metal structure can be a single-layer structure; in other embodiments, the metal structure can be a multi-layer structure, and can comprise a plurality of metal layers stacked in a direction perpendicular to the main surface of the substrate, and the materials of the plurality of metal layers can be the same as or different from each other. When the metal structure comprises a plurality of metal layers, the etching byproducts described above comprise byproducts generated by the reaction of each of the plurality of metal layers with the etching substance.

[0083] In some embodiments, the metal structure comprises a first metal layer and a second metal layer having different materials, and the etching byproducts comprise first byproducts generated by the reaction of the etching gas with the first metal layer and second byproducts generated by the reaction of the etching gas with the second metal layer.

[0084] In some embodiments, the gaseous products comprise products generated by the reaction of the plasma with the first byproducts and products generated by the reaction of the plasma with the second byproducts.

[0085] In some embodiments, the first metal layer comprises aluminum or aluminum-copper alloy, the second metal layer comprises titanium, and the second metal layer is disposed on the side of the first metal layer distal to the substrate.

[0086] ReferenceFigures 1 to 5 For example, the metal structure 103 can include a first metal layer 101 and a second metal layer 102 having different materials, the second metal layer 102 is disposed on a side of the first metal layer 101 away from the substrate 100, and the patterned mask layer 105 is disposed on a side of the second metal layer 102 away from the substrate 100. For example, the first metal layer 101 can include aluminum or aluminum-copper alloy, and the second metal layer 102 can include titanium.

[0087] Metal materials such as aluminum and aluminum-copper alloy have low resistivity and low cost (e.g., lower than noble metals such as gold and silver), and thus the first metal layer can be formed with good electrical properties at low cost using materials such as aluminum or aluminum-copper alloy. The second metal layer can be formed using a titanium layer and disposed on the first metal layer to protect the first metal layer. For example, materials such as aluminum or aluminum-copper alloy can be oxidized in an air environment or can be corroded by reacting with water vapor in the air, or the lattice of these materials can change under heat conditions to produce a rough surface. Forming a titanium layer on the surface of the aluminum or aluminum-copper alloy layer can help avoid the above problems, i.e., avoid oxidation or corrosion of the aluminum or aluminum-copper alloy layer in the air environment, and the metal pattern formed by these materials can have a flat surface. It should be understood that the above material selection is only illustrative, and the present disclosure is not limited thereto.

[0088] In some embodiments, the intermediate structure 120 is a wafer structure, the substrate 100 is a semiconductor wafer, and the metal pattern formed by etching the metal structure 103 can be or include a metal electrode, a metal wire, etc., which can be located in each chip area of the wafer structure. In some embodiments, in subsequent processes, other conductive members can be formed on a side of the metal pattern 103a away from the substrate to be electrically connected to the metal pattern 103a.

[0089] For example, in subsequent processes, a dielectric layer can be formed on the metal pattern 103a, and then an etching process is performed on the dielectric layer and the natural oxide layer 109 to form a via in the dielectric layer and the natural oxide layer 109 and expose a portion of the surface of the metal pattern 103a on a side away from the substrate; a conductive member is formed on a side of the dielectric layer away from the substrate and in the via, and the conductive member is electrically connected to the metal pattern 103a through the via. In some embodiments, in the etching process of forming the via, a portion of the second metal layer 102 is also etched and removed, so that the via exposes a portion of the surface of the first metal layer 101, and the subsequently formed conductive member directly contacts and is electrically connected to the first metal layer 101 through the via.

[0090] For example, in subsequent processes, a dielectric layer can be formed on the metal pattern 103a, and then an etching process is performed on the dielectric layer and the natural oxide layer 109 to form a via in the dielectric layer and the natural oxide layer 109 and expose a portion of the surface of the metal pattern 103a on a side away from the substrate; a conductive member is formed on a side of the dielectric layer away from the substrate and in the via, and the conductive member is electrically connected to the metal pattern 103a through the via. In some embodiments, in the etching process of forming the via, a portion of the second metal layer 102 is also etched and removed, so that the via exposes a portion of the surface of the first metal layer 101, and the subsequently formed conductive member directly contacts and is electrically connected to the first metal layer 101 through the via. Figure 5As shown, in some embodiments, there can be a metal oxide layer 108 on the side surface of the formed metal pattern, since the conductive member connected to the metal pattern 103a later is connected to the metal pattern from the side of the metal pattern away from the substrate (i.e. the top side as shown in the figure), the metal oxide on the side surface of the metal pattern 103a will not substantially adversely affect the electrical properties of the metal pattern 103a and subsequent electrical connection, etc.

[0091] The embodiments of the present disclosure provide a semiconductor device, which includes a substrate and a metal pattern on the substrate, the metal pattern including at least one of one or more metal electrodes and metal wires, and formed by the above semiconductor processing method.

[0092] For example, the semiconductor device can include a micro-electro-mechanical system device or a complementary metal-oxide semiconductor device, etc.; for example, the semiconductor device includes a filter, such as a filter including a solidly mounted resonator (SMR). However, the present disclosure is not limited thereto. The processing method of the present disclosure can be applied to any type of semiconductor device including metal members.

[0093] In some examples, it is verified by experimental examples that the intermediate structure formed by the semiconductor processing method of the present disclosure does not undergo metal post-etching corrosion after being exposed to air and stored.

[0094] For example, in the intermediate structure of the experimental example, the metal structure includes a first metal layer and a second metal layer, the first metal layer is an aluminum layer, and the second metal layer is a titanium layer, and the material of the patterned mask layer is photoresist. After the metal structure is etched by the above semiconductor processing method using chlorine-containing etching gas (e.g. chlorine gas and boron trichloride gas) to form a metal pattern, the intermediate structure is subjected to water vapor plasma treatment; then the intermediate structure subjected to water vapor plasma treatment is exposed to an atmospheric environment for a period of time, and the surface state of the intermediate structure at different time points is tested. After being stored for a period of time, the mask layer (i.e. photoresist) of the intermediate structure is removed, and the surface state of the metal pattern is tested and observed.

[0095] Figures 9 to 12 Pictures showing the surface condition of the intermediate structure subjected to the etching process and water vapor plasma treatment by the semiconductor processing method of the present disclosure after being exposed to an atmospheric environment at different time points in the experimental example.

[0096] Specifically, Figure 9 Pictures showing the surface condition of the intermediate structure after being exposed to an atmospheric environment after water vapor plasma treatment; Figure 10 Pictures showing the surface condition of the intermediate structure after being stored in an atmospheric environment for 24 hours; Figure 11The surface condition of the intermediate structure after being placed in the atmospheric environment for 72 hours is shown; in Figures 9 to 11 In the shown picture, the patterned mask layer (i.e., the photoresist layer) has not been removed, but is still retained on the metal pattern. Figure 12 The surface condition of the intermediate structure (i.e., the metal pattern) after the patterned mask layer is shown.

[0097] As shown in the picture, after the water vapor plasma treatment, no post-etching corrosion occurs when the intermediate structure is exposed to the atmospheric environment; and even if it is placed in the atmospheric environment for a long time, no post-etching corrosion occurs, and the finally formed metal pattern has good appearance quality and reliability. Figures 9 to 12

[0098] Therefore, by the semiconductor processing method of the present disclosure, after the etching process is performed in the etching machine, the etching byproducts are removed by the water vapor plasma treatment in the additional vacuum chamber of the same machine, which can effectively solve the problem of post-etching corrosion caused by etching byproducts, so that the intermediate structure will not cause metal post-etching corrosion when exposed to the atmospheric environment. In some embodiments, compared with the process method without water vapor plasma treatment, the process method of the present disclosure can improve the appearance yield of the formed product from 20% to 80% or more.

[0099] In the above experimental examples, the metal structure including an aluminum layer and a titanium layer is taken as an example for experiment with chlorine-containing etching gas, and it should be understood that the present disclosure is not limited thereto. The concept of the present disclosure of treating etching byproducts by water vapor plasma to avoid metal post-etching corrosion can also be applied to processes for other metal materials and etching substances, for example, the etching substance can also be or include fluorine-containing etching gas, and the metal material can also include copper and other metal materials.

[0100] In the embodiments of the present disclosure, the intermediate structure (for example, a wafer structure) is subjected to metal etching and etching byproduct treatment using the same process machine, which can avoid metal post-etching corrosion caused by exposure of etching byproducts to the atmospheric environment; and the treatment process is continuously performed in the same process machine, which can improve the flow efficiency. That is, using the semiconductor processing method of the embodiments of the present disclosure to form a metal pattern in a semiconductor device can improve the product yield and production efficiency.

[0101] The following points need to be explained:

[0102] (1) In the drawings of the embodiments of the present disclosure, only the structures related to the embodiments of the present disclosure are involved, and other structures can be referred to the general design.

[0103] (2) In the case of no conflict, the features in the same and different embodiments of the present disclosure can be combined with each other.

[0104] ​The above merely describes specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A method of a semiconductor processing process, characterized by, The method comprises: forming an intermediate structure, wherein the intermediate structure comprises a substrate, a metal structure, and a patterned mask layer, the metal structure is located on one side of the substrate, and the patterned mask layer is located on a side of the metal structure away from the substrate, wherein the patterned mask layer covers and contacts a surface of the metal structure away from the substrate; placing the intermediate structure in an etching chamber of an etching machine, and performing an etching process on the metal structure in the etching chamber using an etching substance, the etching process uses the patterned mask layer as an etching mask, removes part of the metal structure, and forms a metal pattern; wherein after the etching process, etching byproducts generated by the reaction of the etching substance and the removed part of the metal structure remain on the surface of the intermediate structure; transferring the intermediate structure from the etching chamber of the etching machine to an additional vacuum chamber of the etching machine, introducing water vapor into the additional vacuum chamber, and dissociating the water vapor into plasma, wherein the plasma reacts with the etching byproducts and generates gaseous products, the reaction of the plasma and the etching byproducts also generates metal oxides, part of the metal oxides is located on the side surface of the metal pattern, and another part of the metal oxides is located on the surface of the patterned mask layer; using a vacuum pump to extract the gaseous products from the additional vacuum chamber, wherein at least the part of the patterned mask layer covering the metal pattern is not removed by the plasma during the reaction of the plasma and the etching byproducts, so that the surface of the metal structure away from the substrate is still covered by the patterned mask layer during the reaction, and after the reaction of the plasma and the etching byproducts is completed, the patterned mask layer is located between the surface of the metal pattern and the metal oxides to space the surface of the metal pattern and the metal oxides apart; and after the reaction of the plasma and the etching byproducts is completed to remove the etching byproducts and generate the metal oxides, the intermediate structure is removed from the etching machine, then the patterned mask layer and the another part of the metal oxides on the patterned mask layer are removed, and the surface of the metal pattern away from the substrate is exposed.

2. The method of claim 1, wherein, The process of transferring the intermediate structure from the etching chamber to the additional vacuum chamber is located in the etching machine, isolated from the atmosphere, and in a vacuum environment.

3. The method of claim 1, wherein, In the etching chamber, the etching byproducts are attached to the side surface of the patterned mask layer and the surface thereof away from the substrate, and the side surface of the metal pattern.

4. The method of claim 1, wherein, After the patterned mask layer is removed, natural oxidation occurs on the surface of the metal pattern away from the substrate and forms a natural oxidation layer.

5. The method of claim 1, wherein The metal structure is a single-layer structure or a multi-layer structure.

6. The method of claim 1, wherein, The metal structure includes a first metal layer and a second metal layer having different materials, and the etching byproducts include a first byproduct resulting from the etching species reacting with the first metal layer and a second byproduct resulting from the etching species reacting with the second metal layer.

7. The semiconductor processing method according to claim 6, characterized in that, The gaseous products include products resulting from the plasma reacting with the first byproduct and products resulting from the plasma reacting with the second byproduct.

8. The semiconductor processing method of claim 6 or 7, wherein, The first metal layer includes aluminum or aluminum-copper alloy, the second metal layer includes titanium, and the second metal layer is disposed on a side of the first metal layer distal from the substrate.

9. The method as claimed in any one of claims 1-7, wherein, The water vapor is dissociated into the plasma under the action of microwaves.

10. The method of claim 1-7, wherein, The material of the metal structure includes a metal or a metal alloy, and the etching species includes a halogen-containing gas.

11. The method as claimed in any one of claims 1-7, wherein, The material of the metal structure is selected from at least one of aluminum, aluminum-copper alloy, titanium, iron, copper, zinc, magnesium, manganese, and cobalt.

12. The method according to any one of claims 1-7, wherein, The etching species is an etching gas and includes chlorine gas or a chlorine-containing compound, the etching byproducts include a chlorine-containing metal salt, and the gaseous products resulting from the plasma and the etching byproducts include hydrogen chloride gas.

13. A semiconductor device, characterized by comprising: A semiconductor device includes a substrate and a metal pattern on the substrate, the metal pattern including at least one of one or more metal electrodes and metal wires, and is formed by the semiconductor processing method of any one of claims 1-12.

14. The semiconductor device of claim 13, wherein, The semiconductor device includes a microelectromechanical system device or a complementary metal-oxide semiconductor device.

15. The semiconductor device of claim 13, wherein, The semiconductor device includes a filter. The semiconductor device includes a microelectromechanical system device or a complementary metal-oxide semiconductor device. The semiconductor device includes a filter.

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