Method for solving tungsten and titanium corrosion residues of on-chip thin-film resistor

Abstract

The invention discloses a method for solving tungsten and titanium corrosion residues of an on-chip thin-film resistor, and belongs to the field of semiconductor chip manufacturing, and the method comprises the following steps: firstly, etching most tungsten and titanium on a prepared metal and thin-film resistor interconnected silicon wafer by using hydrogen peroxide, which is equivalent to main etching; wherein the thin-film resistor is provided with a tungsten-titanium barrier layer; secondly, carrying out wet-process organic cleaning to remove residual reaction byproducts on the tungsten-titanium surface; and finally, removing residual tungsten and titanium by using hydrogen peroxide, which is equivalent to over-etching. Compared with the prior art, the method provided by the invention is high in operability, and a conventional wet process acid tank can meet process requirements; the cost is low, and the used chemical corrosive liquid and special gas are common materials for a semiconductor integrated circuit production line; and the application prospect is wide, and the corrosion of the chromium-silicon thin-film resistor metal interconnection layer can be completed in the manufacturing process of an analog integrated circuit.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor chip manufacturing and relates to a method for solving the problem of tungsten-titanium corrosion residues in on-chip thin-film resistors. Background Art

[0002] In today's era of rapid technological development, semiconductor integrated circuits are undoubtedly at the core of electronic technology, and continue to promote innovation and progress in many fields. From smart phones to high-performance computers, from smart cars to industrial automation control systems, the performance and accuracy of semiconductor integrated circuits directly determine the overall operating efficiency and functional realization of these complex electronic devices.

[0003] With the continuous expansion and diversification of application scenarios, the requirements of circuit systems for resistor components are gradually changing profoundly. Traditional diffusion resistors and injection resistors once played an important role in early semiconductor circuits, but due to their inherent limitations in resistance accuracy, temperature stability, and compatibility with other advanced processes, they are no longer able to meet the increasingly complex and sophisticated design requirements of modern electronic products. For example, in audio processing circuits, the precise amplification and restoration of weak audio signals requires resistors with extremely high precision and extremely low noise characteristics; in high-precision sensor interface circuits, the stability of resistors directly affects the accuracy and reliability of sensor measurement data. Against this background, high-precision thin-film resistors came into being and have demonstrated unique advantages and broad application prospects in the field of analog integrated circuits.

[0004] Thin-film resistors, with their unique manufacturing process and material structure, can achieve more precise resistance control, usually reaching a higher level of accuracy than traditional resistors, and their resistance error range can be controlled within a very small range. At the same time, thin-film resistors also have excellent temperature stability. Under different operating temperature environments, the change in resistance is relatively small, thus ensuring that the circuit can operate stably under various working conditions. In the signal processing chain of analog integrated circuits, high-precision thin-film resistors can effectively reduce signal distortion and improve the fidelity of signal transmission, providing a solid foundation for high-quality audio, video, and various sensor signal processing.

[0005] In the manufacturing process of thin-film resistors, the tungsten-titanium alloy barrier layer plays an indispensable role. This barrier layer is evenly covered on the surface of the thin-film resistor through a fine deposition process. Its primary function is to serve as a solid physical barrier to effectively block the intrusion of impurities, moisture and other substances in the external environment that may damage the thin-film resistor. In the semiconductor manufacturing process, wafers need to go through many complex processes, including photolithography, etching, ion implantation, chemical vapor deposition, etc., all of which have the risk of introducing impurity contamination to varying degrees. The tungsten-titanium alloy barrier layer can provide reliable protection for thin-film resistors in these complex process environments, ensuring that their internal structure and electrical properties are not disturbed. In addition, the barrier layer can also enhance the adhesion between the thin-film resistor and the metal interconnect layer, ensuring a stable and reliable electrical connection during the interconnection process between the metal and the thin-film resistor, and preventing faults such as poor contact or signal transmission interruption caused by interface problems.

[0006] However, the key process step after the metal and thin film resistor are interconnected - the link of removing the tungsten titanium barrier layer on the surface of the thin film resistor, has encountered a difficult technical challenge. According to the conventional process scheme, an etchant is used to remove the tungsten titanium barrier layer. However, in the process of etching the tungsten titanium barrier layer, the actual effect is not satisfactory. When the etchant reacts with the tungsten titanium alloy, obvious white substances will remain on the surface of the thin film resistor, which are confirmed by analysis to be tungsten titanium components that have not been completely corroded. These residual tungsten titanium does not exist in the form of uniform and fine particles, but presents a relatively concentrated and irregular distribution state, and its coverage area and thickness are sufficient to have a significant impact on the subsequent performance of the thin film resistor. What is more serious is that a series of complex reaction by-products are attached to the surface of these white tungsten titanium residues. These by-products are generated during the reaction between the etchant and tungsten titanium due to the incomplete chemical reaction and the participation of other impurities that may exist in the reaction. Their chemical composition and structure are complex and diverse, and may include tungsten titanium compounds that are not completely oxidized, intermediate products produced by the decomposition of the etchant, and new substances formed by combining with trace impurities in the surrounding environment. These reaction byproducts not only further deteriorate the cleanliness and uniformity of the thin-film resistor surface, but also, due to their unknown electrical properties, are very likely to introduce additional electrical interference during subsequent circuit operation.

[0007] In order to solve this problem, technicians tried the traditional corrosion process. The corrosion process usually adds other chemical reagents to the original corrosion system to enhance the corrosion effect, change the chemical balance of the reaction, and promote the further dissolution or decomposition of residual substances. However, in the treatment of tungsten-titanium residues and their surface reaction byproducts, the corrosion process failed to play the expected role. Despite multiple rounds of optimization and adjustment of the type, concentration and treatment conditions of the corrosion reagents, it is still impossible to effectively remove the tungsten-titanium residues. This dilemma makes the surface state of the thin-film resistor unable to meet the standards required by the subsequent process, which in turn has a chain reaction on the manufacturing process of the entire semiconductor device. Therefore, how to effectively solve the tungsten-titanium residues on the surface of thin-film resistors and related problems has become a key technical bottleneck that needs to be overcome in the field of semiconductor integrated circuit manufacturing technology, which is of great significance to promoting technological progress and product quality improvement in the entire industry. Summary of the invention

[0008] The purpose of the present invention is to solve the problem of incomplete tungsten-titanium residue on the surface of thin-film resistors in the prior art, and to provide a method for solving the problem of tungsten-titanium corrosion residue on thin-film resistors.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention proposes a method for solving the problem of tungsten-titanium corrosion residue in on-chip thin-film resistors, comprising:

[0011] Performing a first etching on the prepared silicon wafer interconnected with the metal and thin film resistor, wherein the thin film resistor has a tungsten-titanium barrier layer;

[0012] Cleaning the silicon wafer etched for the first time to remove the reaction byproducts on the surface of the tungsten-titanium barrier layer to obtain a pre-treated silicon wafer;

[0013] The pre-treated silicon wafer is etched a second time to remove the tungsten and titanium residues of the thin film resistor on the silicon wafer.

[0014] Preferably, high-pressure water flushing or organic solvent cleaning is used to obtain the prepared silicon wafer with metal and thin film resistor interconnections.

[0015] Preferably, the first etching is performed on the prepared silicon wafer for interconnecting the metal and thin film resistor, specifically:

[0016] The silicon wafer is etched for the first time using hydrogen peroxide.

[0017] Preferably, the amount of hydrogen peroxide used is determined according to the size of the etching tank.

[0018] Preferably, the temperature of the first etching with hydrogen peroxide is 40°C to 80°C, the volume of hydrogen peroxide is 16L to 32L, and the time of the first etching with hydrogen peroxide is 1min30s to 2min30s; the thickness range of etching tungsten titanium is

[0019] Preferably, the cleaning of the silicon wafer etched for the first time is specifically performed as follows:

[0020] The silicon wafer etched for the first time is cleaned using an organic cleaning solvent.

[0021] Preferably, the cleaning temperature using the organic cleaning solvent is 50° C. to 80° C., and the cleaning time is 25 min to 35 min.

[0022] Preferably, the second etching of the pretreated silicon wafer is specifically performed as follows:

[0023] The pretreated silicon wafer is etched a second time using hydrogen peroxide.

[0024] Preferably, the temperature of the second etching with hydrogen peroxide is 40°C to 80°C, the volume of hydrogen peroxide is 16L to 32L, and the time of the second etching with hydrogen peroxide is 30s to 1min30s; the thickness range of etching tungsten titanium is

[0025] Preferably, after the second etching, the presence of tungsten titanium residue is determined by testing whether the error between the resistance value of the thin film resistor and the actual design value is less than 3%; if the error between the resistance value of the thin film resistor and the actual design value is less than or equal to 3%, there is no tungsten titanium residue; if the error between the resistance value of the thin film resistor and the actual design value is greater than 3%, there is tungsten titanium residue.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention proposes a method for solving the problem of tungsten-titanium corrosion residues in thin-film resistors on a chip. Precise etching can control the connection between the metal and the thin-film resistor, reduce the risk of unnecessary short circuits or open circuits, and optimize the current transmission path. For thin-film resistors with tungsten-titanium barrier layers, this barrier layer itself can prevent metal atoms from diffusing into the resistor layer and affecting the electrical properties of the resistor. The cleaning process removes the reaction byproducts on the surface of the tungsten-titanium barrier layer. These byproducts may introduce additional impurities, affecting the conductivity and stability of the resistor. As an intermediate link, the cleaning step can ensure that each process step is carried out on a relatively clean surface. This is conducive to better compatibility of subsequent process steps with the current etching process, reducing process failures or performance degradation caused by surface contamination. The second etching removes the tungsten-titanium residues on the thin-film resistor. Tungsten-titanium residues may cause uneven local electric field distribution and increase the risk of leakage. After removing these residues, the resistor can be made more stable at the operating voltage, reducing leakage current, thereby improving the power efficiency and reliability of the entire circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 This is a diagram showing the residual results of tungsten and titanium after a single corrosion process according to the present invention.

[0030] Figure 2 This is a diagram showing the result of the stepwise etching without tungsten and titanium residues of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0035] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0037] The present invention proposes a method for solving the problem of tungsten-titanium corrosion residue in on-chip thin-film resistors, comprising the following steps:

[0038] Step 1: Use hydrogen peroxide to perform the first etching on the prepared silicon wafer for metal and thin film resistor interconnection, such as Figure 1 and Figure 2 As shown, beige is aluminum wire, gray is substrate, and light green is resistor. Figure 1 There are strips of titanium tungsten residues at the overlap of the resistor and the aluminum wire in the red circle. Most of the tungsten titanium is etched away by the first etching (80% of the tungsten titanium is etched away); the thin film resistor has a tungsten titanium barrier layer with a thickness range of

[0039] Among them, high-pressure water or organic solvent is used to obtain the prepared silicon wafer with metal and thin film resistor interconnection to ensure that the surface of the silicon wafer is clean and free of impurities.

[0040] The volume of hydrogen peroxide used is 16L~32L, the reaction temperature is 40℃~80℃, and the time for the first etching with hydrogen peroxide is 1min30s~2min30s; the thickness range of etching tungsten titanium

[0041] Step 2: Clean the silicon wafer etched for the first time to remove the reaction byproducts remaining on the surface of tungsten and titanium to obtain a pretreated silicon wafer.

[0042] Among them, an organic cleaning solvent is used to clean the silicon wafer etched for the first time, and the amount of organic solvent used is 16L~32L; the organic cleaning solvent can be SYS9070, SYS700, EKC270 cleaning solution, etc., which have an organic cleaning effect; whether to add ultrasonic treatment is determined according to the conditions of the machine itself.

[0043] The cleaning temperature using an organic cleaning solvent is 50°C to 80°C, and the cleaning time is 25min to 35min.

[0044] Step 3: Use hydrogen peroxide to perform a second etching on the pretreated silicon wafer, and etch away the remaining tungsten and titanium through the second etching (etch away the remaining 20% ​​of tungsten and titanium).

[0045] The volume of hydrogen peroxide used is 16L~32L, the reaction temperature is 40℃~80℃, and the time for the second etching with hydrogen peroxide is 30s~1min30s; the thickness range of etching tungsten titanium

[0046] Step 4: Check with a microscope or test whether the resistance value of the thin film resistor is different from the actual design value (whether the error is less than 3%) to determine whether there is any tungsten-titanium residue. If the error between the resistance value of the thin film resistor and the actual design value is less than or equal to 3%, there is no tungsten-titanium residue; if the error between the resistance value of the thin film resistor and the actual design value is greater than 3%, there is tungsten-titanium residue. Figure 2 This is the result diagram of the overlapping position of the resistor and the aluminum wire and the absence of titanium tungsten residue on the resistor.

[0047] The first etching using hydrogen peroxide has the following advantages:

[0048] 1) Hydrogen peroxide has a certain oxidizing property and can selectively react with the tungsten-titanium barrier layer in the first etching. Compared with the main materials of silicon wafers and thin-film resistors, hydrogen peroxide can act on the barrier layer first. This selectivity helps to accurately remove part of the barrier layer material in the initial etching stage while minimizing damage to the thin-film resistor and silicon wafer below. For example, in the complex structure of an integrated circuit, there may be other sensitive electronic components or materials around the thin-film resistor. The selective corrosion of hydrogen peroxide can ensure that these surrounding components are not affected during the initial processing of the barrier layer, maintaining the integrity of the entire structure.

[0049] Since hydrogen peroxide has a relatively mild chemical property, relatively fine etching can be achieved by controlling etching parameters (such as concentration, temperature, time, etc.). This is very important for high-precision thin-film resistor applications, because in analog integrated circuits, even small structural changes may affect the performance of resistors. Using hydrogen peroxide for the first etching can provide a good starting state for subsequent more precise processing.

[0050] 2) In addition to removing part of the barrier material during the etching process, hydrogen peroxide can also clean the surface. It can oxidize and decompose some organic pollutants or slight oxide layers on the surface of the barrier layer. If these pollutants are not removed, they may affect the reaction in subsequent processes or introduce additional impurities.

[0051] The second etching using hydrogen peroxide has the following advantages:

[0052] 1) After the first etching and cleaning, there will still be a small amount of tungsten titanium residue. Hydrogen peroxide can continue to exert its oxidizing properties in the second etching to further corrode these residues. It can chemically react with the residual tungsten titanium and convert it into soluble compounds or volatile substances, thereby effectively reducing the amount of tungsten titanium residue on the surface of the thin film resistor. This gradual removal method helps to more accurately control the material composition of the thin film resistor surface, so that the final resistor surface meets the design requirements.

[0053] Hydrogen peroxide can be used to treat the newly exposed tungsten-titanium materials after the first etching or the tungsten-titanium-reaction byproduct complexes that remain due to incomplete cleaning. It can decompose these substances through chemical reactions. For example, for some tungsten-titanium-oxide complexes, hydrogen peroxide can further oxidize the oxides and disintegrate the entire complex structure, thereby achieving the removal of these stubborn residues.

[0054] 2) The second etching with hydrogen peroxide can make the surface of the thin film resistor smoother. The residual tungsten and titanium may cause the surface to be uneven, thus affecting the subsequent process (such as metal deposition) or electrical properties (such as uneven electric field distribution). By etching again with hydrogen peroxide, this surface irregularity can be reduced and the surface quality of the thin film resistor can be improved.

[0055] Example 1

[0056] Step 1: On the prepared metal and thin film resistor (with tungsten titanium barrier layer ) Use hydrogen peroxide to etch away 80% of the tungsten and titanium on the interconnected silicon wafers. (equivalent to main etching);

[0057] Among them, organic solvent cleaning is used to pre-treat the silicon wafer to ensure that the surface of the silicon wafer is clean and free of impurities; the hydrogen peroxide used is pure hydrogen peroxide, the amount of hydrogen peroxide used is 16L, the hydrogen peroxide etching temperature is 40°C, and the hydrogen peroxide etching time is 1min30s.

[0058] Step 2: Use SYS9070 cleaning solution to clean the silicon wafer after the first etching to remove the reaction byproducts on the surface of the remaining tungsten and titanium to obtain a pre-treated silicon wafer;

[0059] Among them, the cleaning liquid is pure liquid, the cleaning liquid dosage is 16L, the cleaning temperature is 50°C, and the cleaning time is 25min.

[0060] Step 3: Use hydrogen peroxide to remove the remaining 20% ​​of tungsten titanium and the thickness (equivalent to over-etching);

[0061] The hydrogen peroxide is pure hydrogen peroxide, the amount of hydrogen peroxide used is 16 L, the temperature of hydrogen peroxide etching is 40° C., and the hydrogen peroxide etching time is 30 s.

[0062] Step 4: Check with a microscope or test whether there is any error between the resistance value of the thin film resistor and the actual design value (if the error is less than or equal to 3%, it can be determined that there is no tungsten titanium residue).

[0063] Example 2

[0064] Step 1: On the prepared metal and thin film resistor (with tungsten titanium barrier layer ) Use hydrogen peroxide to etch away 80% of the tungsten and titanium on the interconnected silicon wafers. (equivalent to main etching);

[0065] Among them, organic solvent cleaning is used to pre-treat the silicon wafer to ensure that the surface of the silicon wafer is clean and free of impurities; the hydrogen peroxide used is pure hydrogen peroxide, the amount of hydrogen peroxide used is 24L, the hydrogen peroxide etching temperature is 60°C, and the hydrogen peroxide etching time is 2min.

[0066] Step 2: Use SYS9070 cleaning solution to clean the silicon wafer after the first etching to remove the reaction byproducts on the surface of the remaining tungsten and titanium to obtain a pre-treated silicon wafer;

[0067] Among them, the cleaning liquid is pure liquid, the cleaning liquid dosage is 24L, the cleaning temperature is 65°C, and the cleaning time is 30min.

[0068] Step 3: Use hydrogen peroxide to remove the remaining 20% ​​of tungsten titanium and the thickness (equivalent to over-etching);

[0069] The hydrogen peroxide is pure hydrogen peroxide, the amount of hydrogen peroxide used is 24 L, the temperature of hydrogen peroxide etching is 60° C., and the hydrogen peroxide etching time is 1 min.

[0070] Step 4: Check with a microscope or test whether there is any error between the resistance value of the thin film resistor and the actual design value (if the error is less than or equal to 3%, it can be determined that there is no tungsten titanium residue).

[0071] Example 3

[0072] Step 1: On the prepared metal and thin film resistor (with tungsten titanium barrier layer ) Use hydrogen peroxide to etch away 80% of the tungsten and titanium on the interconnected silicon wafers. (equivalent to main etching);

[0073] Among them, organic solvent cleaning is used to pre-treat the silicon wafer to ensure that the surface of the silicon wafer is clean and free of impurities; the hydrogen peroxide used is pure hydrogen peroxide, the amount of hydrogen peroxide used is 32L, the hydrogen peroxide etching temperature is 80°C, and the hydrogen peroxide etching time is 2min30s.

[0074] Step 2: Use SYS9070 cleaning solution to clean the silicon wafer after the first etching to remove the reaction byproducts on the surface of the remaining tungsten and titanium to obtain a pre-treated silicon wafer;

[0075] Among them, the cleaning liquid is pure liquid, the cleaning liquid dosage is 32L, the cleaning temperature is 80°C, and the cleaning time is 35min.

[0076] Step 3: Use hydrogen peroxide to remove the remaining 20% ​​of tungsten titanium and the thickness (equivalent to over-etching);

[0077] The hydrogen peroxide is pure hydrogen peroxide, the amount of hydrogen peroxide used is 32 L, the temperature of hydrogen peroxide etching is 80° C., and the hydrogen peroxide etching time is 1 min 30 s.

[0078] Step 4: Check with a microscope or test whether there is any error between the resistance value of the thin film resistor and the actual design value (if the error is less than or equal to 3%, it can be determined that there is no tungsten titanium residue).

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for solving the problem of tungsten-titanium corrosion residue in on-chip thin film resistors, characterized in that: include: Performing a first etching on the prepared silicon wafer interconnected with the metal and thin film resistor, wherein the thin film resistor has a tungsten-titanium barrier layer; Cleaning the silicon wafer etched for the first time to remove the reaction byproducts on the surface of the tungsten-titanium barrier layer to obtain a pre-treated silicon wafer; The pre-treated silicon wafer is etched a second time to remove the tungsten and titanium residues of the thin film resistor on the silicon wafer.

2. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 1, characterized in that: The prepared silicon wafer with metal and thin film resistor interconnections is obtained by using high pressure water or organic solvent cleaning.

3. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 1, characterized in that: The first etching is performed on the prepared silicon wafer for interconnecting the metal and thin film resistor, specifically: The silicon wafer is etched for the first time using hydrogen peroxide.

4. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 3, characterized in that: The amount of hydrogen peroxide used depends on the size of the etching tank.

5. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 3, characterized in that: The temperature of the first etching with hydrogen peroxide is 40℃~80℃, the volume of hydrogen peroxide is 16L~32L, and the time of the first etching with hydrogen peroxide is 1min30s~2min30s; the thickness range of etching tungsten titanium 6. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 1, characterized in that: The cleaning of the silicon wafer etched for the first time is specifically as follows: The silicon wafer etched for the first time is cleaned using an organic cleaning solvent.

7. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 1, characterized in that: The cleaning temperature using an organic cleaning solvent is 50°C to 80°C, and the cleaning time is 25min to 35min.

8. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 1, characterized in that: The second etching of the pretreated silicon wafer is specifically performed as follows: The pretreated silicon wafer is etched a second time using hydrogen peroxide.

9. The method for solving the problem of tungsten-titanium corrosion residue in on-chip thin film resistors according to claim 8, characterized in that: The temperature of the second etching with hydrogen peroxide is 40℃~80℃, the volume of hydrogen peroxide is 16L~32L, and the time of the second etching with hydrogen peroxide is 30s~1min30s; the thickness range of etching tungsten titanium 10. The method for solving the problem of residual tungsten-titanium corrosion in on-chip thin film resistors according to claim 1, characterized in that: After the second etching, the error between the thin film resistor value and the actual design value is tested to see if it is less than 3% to determine whether there is any tungsten and titanium residue. If the error between the resistance value of the thin film resistor and the actual design value is less than or equal to 3%, there is no tungsten and titanium residue; If the error between the thin film resistor value and the actual design value is greater than 3%, there is tungsten and titanium residue.

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