A method for manufacturing an electrothermal MEMS driving arm and an electrothermal MEMS driving arm

Abstract

A method for making an electrothermal MEMS drive arm includes the following steps: 1) selecting high-resistance silicon as a substrate; 2) patterning the substrate to form a mask of a pre-designed conductive loop pattern; 3) doping the substrate using an injection method or a diffusion method to form a conductive loop, which serves as a heating resistor layer; 4) making an insulating material on the heating resistor layer as an insulating layer; 5) making a material with a high thermal expansion coefficient on the insulating layer as a first structural layer; 6) etching the bottom of the substrate to leave high-resistance silicon of a set thickness as a second structural layer; 7) performing front patterning etching on the upper part of the substrate according to the pre-designed MEMS drive arm shape; and finally completing the production of the electrothermal MEMS drive arm. Advantages: Silicon serves as both a structural layer and a heating resistor layer, eliminating the trouble of making a heating resistor layer, simplifying the process steps of the heating resistor layer of the electrothermal MEMS drive arm, and improving efficiency.

Description

Technical Field

[0001] The invention relates to a method for manufacturing an electrothermal MEMS driving arm and the electrothermal MEMS driving arm, belonging to the field of micro-mechanical electronic systems. Background Art

[0002] The electrothermal MEMS drive arm based on the thermal bimorph structure drives the device structure by applying voltage to the conductive circuit layer (heating resistor layer) to generate Joule heat, which has the advantages of large rotation angle, large displacement, low driving voltage, etc. The existing electrothermal MEMS device heating resistor layer manufacturing process (such as CN106066535A, CN104020561B) can only grow a conductive metal film layer in the Bimorph structure layer and insulate the conductive metal film layer. This process requires the cumulative preparation of multiple layers of thin films, which introduces uncontrollable factors such as stress, thickness, oxidation, and diffusion of the multilayer films, increases the process difficulty of manufacturing the device, and deteriorates the process consistency and structural stability of the device. Summary of the invention

[0003] The technical problem to be solved by the invention is how to simplify the process of manufacturing the heating resistor layer of the electrothermal MEMS drive arm and improve the consistency and stability of the heating resistor layer process.

[0004] The technical solution created by the present invention is a method for manufacturing an electrothermal MEMS driving arm, which at least comprises a heating resistor layer 4, a first structural layer 6, a second structural layer 7, and an insulating layer 5 between the first structural layer 6 and the second structural layer 7, and is characterized in that it comprises the following steps:

[0005] Step 1), select high-resistance silicon as substrate 1;

[0006] Step 2), patterning is performed on the substrate 1 to form a mask of a pre-designed conductive circuit pattern 3;

[0007] Step 3), doping the substrate 1 by an implantation method or a diffusion method to form a conductive loop, which serves as a heating resistor layer 4;

[0008] Step 4), making an insulating material on the heating resistor layer 4 as an insulating layer 5;

[0009] Step 5), making a material with a high thermal expansion coefficient on the insulating layer 5 as the first structural layer 6;

[0010] Step 6), etching the bottom of the substrate 1, leaving a set thickness of high-resistance silicon as the second structure layer 7;

[0011] Step 7), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0012] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

[0013] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps:

[0014] Step 1), select high-resistance silicon as substrate 1;

[0015] Step 2), patterning is performed on the substrate 1 to form a mask of a pre-designed conductive circuit pattern 3;

[0016] Step 3), doping the substrate 1 by an implantation method or a diffusion method to form a conductive loop, which serves as a heating resistor layer 4;

[0017] Step 4), making an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4;

[0018] Step 5), etching the bottom of the substrate 1, leaving a set thickness of high-resistance silicon as the second structure layer 7;

[0019] Step 6), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0020] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

[0021] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps:

[0022] Step 1), select high-resistance silicon as substrate 1;

[0023] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etching stop layer 8 as the second structural layer 7;

[0024] Step 3), masking and photolithography are performed on the deep silicon etch stop layer 8 to leave an N-type ion doped area;

[0025] Step 4), doping N-type ions into the interior of the P-type ion doping area according to the pre-designed conductive loop pattern 3, to form N-type silicon as the heating resistor layer 4;

[0026] Step 5), removing the mask, and making an insulating material on the heating resistor layer 4 as an insulating layer 5;

[0027] Step 6), making a material with a high thermal expansion coefficient on the insulating layer 5 as the first structural layer 6;

[0028] Step 7), etching the bottom of the substrate 1 to the deep silicon etch stop layer 8;

[0029] Step 8), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0030] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 7) and step 8) can be interchanged.

[0031] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps:

[0032] Step 1), select high-resistance silicon as substrate 1;

[0033] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etch stop layer 8, which serves as both the second structural layer 7 and the heating resistor layer 4;

[0034] Step 3), removing the mask, and making an insulating material on the heating resistor layer 4 as an insulating layer 5;

[0035] Step 4), making a material with a high thermal expansion coefficient on the insulating layer 5 as the first structural layer 6;

[0036] Step 5), etching the bottom of the substrate 1 to the heating resistor layer 4;

[0037] Step 6), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0038] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

[0039] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps:

[0040] Step 1), select high-resistance silicon as substrate 1;

[0041] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etching stop layer 8 as the second structural layer 7;

[0042] Step 3), masking and photolithography are performed on the deep silicon etch stop layer 8 to leave an N-type ion doped area;

[0043] Step 4), doping N-type ions into the interior of the P-type ion doping area according to the pre-designed conductive loop pattern 3, to form N-type silicon as the heating resistor layer 4;

[0044] Step 5), making an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4;

[0045] Step 6), etching the bottom of the substrate 1 to the deep silicon etch stop layer 8;

[0046] Step 7), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0047] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

[0048] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps:

[0049] Step 1), select high-resistance silicon as substrate 1;

[0050] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etch stop layer 8, which serves as both the second structural layer 7 and the heating resistor layer 4;

[0051] Step 3), making an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4;

[0052] Step 4), etching the bottom of the substrate 1 to the heating resistor layer 4;

[0053] Step 5), the upper part of the substrate 1 is patterned and etched in the front side according to the pre-designed MEMS driving arm shape, and finally the electrothermal MEMS driving arm is released, thereby completing the manufacture of the electrothermal MEMS driving arm.

[0054] The deep silicon etch stop layer 8 formed in step 2) can be grown on the upper layer of the substrate 1 in an epitaxial manner.

[0055] An electrothermal MEMS driving arm, one end of which is connected to a substrate 1, and the other end is connected to a driven unit 9. The electrothermal MEMS driving arm includes a first structural layer 6 and a second structural layer 7, and is characterized in that it also includes a heating resistor layer 4 formed by doping part or all of the second structural layer 7.

[0056] The electrothermal MEMS driving arm further includes an insulating layer 5 , which is located above the heating resistor layer 4 .

[0057] The first structural layer 6 is metal aluminum or polymer, and the second structural layer 7 is high-resistance silicon or P-type silicon or N-type silicon.

[0058] The driven unit 9 is a micromirror surface or a microstructure platform.

[0059] The electrothermal MEMS driving arm is a folded beam structure, and the first structural layer 6 of the folded beam structure is divided into three sections, which are respectively located on the three sections of the folded beam structure.

[0060] The electrothermal MEMS driving arm is a U-shaped beam structure or a beam structure with bending.

[0061] The first structural layer 6 on the electrothermal MEMS driving arm is discontinuous.

[0062] The electrothermal MEMS driving arm further comprises a via through hole and a metal lead, and the metal lead is connected to the heating resistor layer 4 through the via through hole.

[0063] Advantages of the invention: The invention point of the invention is that silicon is used as both a structural layer and a heating resistor layer, eliminating the trouble of making a heating resistor layer. The heating resistor layer is made by ion implantation, which simplifies the process steps of the heating resistor layer of the electrothermal MEMS drive arm and improves efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a structural schematic diagram of an electrothermal MEMS drive arm.

[0065] Figure 2 yes Figure 1 Schematic diagram of the heating resistor layer 4.

[0066] Figure 3 It is a schematic diagram of the production process of Example 1.

[0067] Figure 4 It is a schematic diagram of the production process of Example 2.

[0068] Figure 5 It is a schematic diagram of the production process of Example 3.

[0069] Figure 6It is a schematic diagram of the production process of Example 4.

[0070] Figure 7 It is a schematic diagram of the production process of Example 5.

[0071] Figure 8 It is a schematic diagram of the production process of Example 6.

[0072] Fig. 9 A top view of the electrothermal MEMS actuator arm.

[0073] Fig.10 A top view of another electrothermal MEMS actuator arm.

[0074] Fig.11 yes Fig. 9 Deformation resulting from heating.

[0075] Fig.12 yes Fig.10 Deformation resulting from heating.

[0076] Fig.13 It is a top view of the multi-section electrothermal MEMS actuator arm.

[0077] Fig.14 It is a top view of a multi-section electrothermal MEMS driving arm connected to a driven unit.

[0078] Fig.15 It is a top view of a single-section electrothermal MEMS driving arm connected to a driven unit.

[0079] Fig.16 It is a top view of two electrothermal MEMS driving arms connected to the driven unit.

[0080] Fig.17 It is a top view of four electrothermal MEMS driving arms connected to the driven unit.

[0081] In the figure, 1 is a substrate, 2 is a photoresist, 3 is a conductive circuit pattern, 4 is a heating resistor layer, 5 is an insulating layer, 6 is a first structural layer, 7 is a second structural layer, 8 is a deep silicon etch stop layer, and 9 is a driven unit. DETAILED DESCRIPTION

[0082] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps:

[0083] Step 1), select high-resistance silicon as substrate 1;

[0084] Step 2), patterning is performed on the substrate 1 to form a mask of a pre-designed conductive circuit pattern 3;

[0085] Step 3), doping the substrate 1 by an implantation method or a diffusion method to form a conductive loop, which serves as a heating resistor layer 4;

[0086] Step 4), making an insulating material on the heating resistor layer 4 as an insulating layer 5;

[0087] Step 5), making a material with a high thermal expansion coefficient on the insulating layer 5 as the first structural layer 6;

[0088] Step 6), etching the bottom of the substrate 1, leaving a set thickness of high-resistance silicon as the second structure layer 7;

[0089] Step 7), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0090] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

[0091] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps:

[0092] Step 1), select high-resistance silicon as substrate 1;

[0093] Step 2), patterning is performed on the substrate 1 to form a mask of a pre-designed conductive circuit pattern 3;

[0094] Step 3), doping the substrate 1 by an implantation method or a diffusion method to form a conductive loop, which serves as a heating resistor layer 4;

[0095] Step 4), making an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4;

[0096] Step 5), etching the bottom of the substrate 1, leaving a set thickness of high-resistance silicon as the second structure layer 7;

[0097] Step 6), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0098] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

[0099] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps:

[0100] Step 1), select high-resistance silicon as substrate 1;

[0101] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etching stop layer 8 as the second structural layer 7;

[0102] Step 3), masking and photolithography are performed on the deep silicon etch stop layer 8 to leave an N-type ion doped area;

[0103] Step 4), doping N-type ions into the interior of the P-type ion doping area according to the pre-designed conductive loop pattern 3, to form N-type silicon as the heating resistor layer 4;

[0104] Step 5), removing the mask, and making an insulating material on the heating resistor layer 4 as an insulating layer 5;

[0105] Step 6), making a material with a high thermal expansion coefficient on the insulating layer 5 as the first structural layer 6;

[0106] Step 7), etching the bottom of the substrate 1 to the deep silicon etch stop layer 8;

[0107] Step 8), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0108] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 7) and step 8) can be interchanged.

[0109] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps:

[0110] Step 1), select high-resistance silicon as substrate 1;

[0111] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etch stop layer 8, which serves as both the second structural layer 7 and the heating resistor layer 4;

[0112] Step 3), removing the mask, and making an insulating material on the heating resistor layer 4 as an insulating layer 5;

[0113] Step 4), making a material with a high thermal expansion coefficient on the insulating layer 5 as the first structural layer 6;

[0114] Step 5), etching the bottom of the substrate 1 to the heating resistor layer 4;

[0115] Step 6), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0116] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

[0117] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps:

[0118] Step 1), select high-resistance silicon as substrate 1;

[0119] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etching stop layer 8 as the second structural layer 7;

[0120] Step 3), masking and photolithography are performed on the deep silicon etch stop layer 8 to leave an N-type ion doped area;

[0121] Step 4), doping N-type ions into the interior of the P-type ion doping area according to the pre-designed conductive loop pattern 3, to form N-type silicon as the heating resistor layer 4;

[0122] Step 5), making an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4;

[0123] Step 6), etching the bottom of the substrate 1 to the deep silicon etch stop layer 8;

[0124] Step 7), performing front patterning etching on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape;

[0125] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

[0126] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps:

[0127] Step 1), select high-resistance silicon as substrate 1;

[0128] Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate 1 with P-type ions to form a deep silicon etch stop layer 8, which serves as both the second structural layer 7 and the heating resistor layer 4;

[0129] Step 3), making an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4;

[0130] Step 4), etching the bottom of the substrate 1 to the heating resistor layer 4;

[0131] Step 5), the upper part of the substrate 1 is patterned and etched in the front side according to the pre-designed MEMS driving arm shape, and finally the electrothermal MEMS driving arm is released, thereby completing the manufacture of the electrothermal MEMS driving arm.

[0132] The deep silicon etch stop layer 8 formed in step 2) can be grown on the upper layer of the substrate 1 in an epitaxial manner.

[0133] An electrothermal MEMS driving arm, one end of which is connected to a substrate 1, and the other end is connected to a driven unit 9. The electrothermal MEMS driving arm includes a first structural layer 6 and a second structural layer 7, and is characterized in that it also includes a heating resistor layer 4 formed by doping part or all of the second structural layer 7.

[0134] The electrothermal MEMS driving arm further includes an insulating layer 5 , which is located above the heating resistor layer 4 .

[0135] The first structural layer 6 is metal aluminum or polymer, and the second structural layer 7 is high-resistance silicon or P-type silicon or N-type silicon.

[0136] The driven unit 9 is a micromirror surface or a microstructure platform.

[0137] The electrothermal MEMS driving arm is a folded beam structure, and the first structural layer 6 of the folded beam structure is divided into three sections, which are respectively located on the three sections of the folded beam structure.

[0138] The electrothermal MEMS driving arm is a U-shaped beam structure or a beam structure with bending.

[0139] The first structural layer 6 on the electrothermal MEMS driving arm is discontinuous.

[0140] The electrothermal MEMS driving arm further comprises a via through hole and a metal lead, and the metal lead is connected to the heating resistor layer 4 through the via through hole.

[0141] like Figure 1 , 2 , Figure 9-17As shown, an electrothermal MEMS driving arm, one end of which is connected to a substrate 1, and the other end is connected to a driven unit 9. The electrothermal MEMS driving arm includes a first structural layer 6 and a second structural layer 7, and is characterized in that it also includes a heating resistor layer 4 formed by doping inside the second structural layer 7 or the entire second structural layer 7.

[0142] The electrothermal MEMS drive arm further comprises an insulating layer 5, which is located above the heating resistor layer 4. The first structural layer 6 is metal aluminum or polymer (such as SU-8, PVDF, PMMI, PI, etc.), and the second structural layer 7 is high-resistance silicon. The driven unit 9 is a mirror.

[0143] like Fig.13 , 14 As shown, the electrothermal MEMS driving arm is a folded beam structure, and the first structural layer 6 of the folded beam structure is divided into three sections, which are respectively located on the three sections of the folded beam structure. At this time, the first structural layer 6 is discontinuous.

[0144] like Fig. 9 , Fig.10 As shown, the electrothermal MEMS drive arm is a U-shaped beam structure. Fig.11 , Fig.12 As shown, the electrothermal MEMS actuator arm is a beam structure with bending.

[0145] The electrothermal MEMS driving arm further comprises a via through hole and a metal lead, and the metal lead is connected to the heating resistor layer 4 through the via through hole.

[0146] Example 1

[0147] like Figure 3 As shown, a method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least includes a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, and is characterized in that it includes the following steps.

[0148] Step 1), select high-resistance silicon as substrate 1.

[0149] Step 2), patterning is performed on the substrate 1, that is, photoresist is uniformly coated (such as Figure 3 a), and then photolithography is performed to form a mask of a pre-designed conductive circuit pattern 3, as shown in FIG. Figure 3 As shown in b.

[0150] Step 3), doping the substrate 1 by implantation or diffusion (the ions can be P-type ions or N-type ions) to form a conductive loop, which serves as the heating resistor layer 4. Figure 3 As shown in c.

[0151] Step 4), remove the photoresist 2, and make an insulating material (such as depositing a SiO2 thin film layer) on the heating resistor layer 4 as an insulating layer 5, such as Figure 3 d. At this point, via holes and metal leads can be made, and the specific production method is: patterning is performed on the insulating layer 5, that is, photoresist is uniformly coated, and then photolithography is performed to form a via mask; the insulating layer 5 is etched using the via mask to form a via hole, and then the via mask is removed; a conductive material (such as a metal film) is deposited on the insulating layer 5, and photolithography and etching or liftoff is performed to form a metal lead.

[0152] Step 5), a material with a high thermal expansion coefficient (such as deposited metal aluminum) is fabricated on the insulating layer 5, and a first structural layer 6 is formed by photolithography and etching or liftoff. Figure 3 As shown in e; if the material with a high thermal expansion coefficient is the same as the metal lead material, the metal lead is formed together with the first structural layer 6.

[0153] Step 6), the bottom of the substrate 1 is etched to leave high-resistance silicon of a set thickness as the second structure layer 7.

[0154] Step 7), the upper part of the substrate 1 is subjected to front patterning etching according to the pre-designed MEMS driving arm shape.

[0155] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

[0156] When selecting the material of the substrate 1 , it can be high-resistance silicon, P-type silicon or N-type silicon.

[0157] When P-type silicon is selected, in step 3), the doped ions can be P-type ions or N-type ions. However, when doping P-type ions, the doping concentration is much higher than the concentration of P-type ions in substrate 1; when doping N-type ions, after doping, a PN junction is formed with substrate 1, and the voltage applied to the N-type region is higher than the voltage of the P-type region, forming a reverse bias of the PN junction.

[0158] When N-type silicon is selected, in step 3), the doped ions can be P-type ions or N-type ions. However, when doping N-type ions, the doping concentration is much higher than the concentration of N-type ions in substrate 1; when doping P-type ions, after doping, a PN junction is formed with substrate 1, and the voltage applied to the N-type region is higher than the voltage of the P-type region, forming a reverse bias of the PN junction.

[0159] Example 2

[0160] The difference between this embodiment and the first embodiment is that the electrothermal MEMS driving arm is not provided with the insulating layer 5 .

[0161] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps.

[0162] Step 1), select high-resistance silicon as substrate 1.

[0163] Step 2), patterning is performed on the substrate 1, that is, photoresist is uniformly coated (such as Figure 4 a), and then photolithography is performed to form a mask of a pre-designed conductive circuit pattern 3, as shown in FIG. Figure 4 As shown in b.

[0164] Step 3), doping the substrate 1 by implantation or diffusion (the ions can be P-type ions or N-type ions) to form a conductive loop, which serves as the heating resistor layer 4. Figure 4 As shown in c.

[0165] Step 4), remove the photoresist 2, make an insulating material with a high thermal expansion coefficient on the upper layer of the heating resistor layer 4, and form a first structural layer 6 by photolithography and etching or liftoff, such as Figure 4 As shown in d.

[0166] Step 5), the bottom of the substrate 1 is etched to leave high-resistance silicon of a set thickness as the second structural layer 7.

[0167] Step 6), front-side patterning etching is performed on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape.

[0168] Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

[0169] Example 3

[0170] like Figure 5 As shown, this embodiment is implemented by using a multiple ion doping process on a bare silicon wafer, and a deep silicon etch stop layer 8 is formed by a P-type ion doped region in a high-resistance silicon substrate 1. When the silicon substrate 1 is wet-etched by KOH or TMAH to form a second structure layer 7, etching to the deep silicon etch stop layer 8 will cause a self-stop phenomenon. Compared with the expensive price of SOI silicon wafers, this embodiment can accurately control the thickness of the second structure layer 7 on a bare silicon wafer by adjusting the depth of the N-type ion doped region, thereby reducing the device cost.

[0171] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprises a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps.

[0172] Step 1), select high-resistance silicon as substrate 1.

[0173] Step 2), patterning is performed on the substrate 1 (i.e., photoresist is uniformly coated on the substrate 1, and then photolithography is performed) to form a mask pattern as a P-type ion doped region, such as Figure 5 As shown in a.

[0174] Among them, this step 2) is an optional step, that is, after patterning, what is doped in step 3) is the P-type ion doped area; if not patterned, what is doped in step 3) is the surface of the substrate 1.

[0175] Step 3), use an implantation method or a diffusion method to perform P-type ion heavy doping on the surface of the substrate 1 or the P-type ion doped area to form a deep silicon etch stop layer 8, and the deep silicon etch stop layer 8 is used as the second structural layer 7, such as Figure 5 As shown in b.

[0176] Step 4), masking and photolithography are performed on the deep silicon etch stop layer 8 (i.e., photoresist 2 is evenly coated on the etch stop layer 8, and then exposed and developed), leaving an N-type ion doped area, such as Figure 5 As shown in c.

[0177] Step 5), N-type ions are doped into the P-type ion doped area according to the pre-designed conductive loop pattern 3 to form N-type silicon, which is used as the heating resistor layer 4. Figure 5 As shown in d.

[0178] Step 6), remove the mask (ie remove the photoresist 2), such as Figure 5 As shown in FIG. 5 , an insulating material (for example, a SiO2 layer is deposited) is formed on the heating resistor layer 4 as an insulating layer 5. Figure 5 f. At this point, via holes and metal leads can be made, and the making method is the same as step 4 in embodiment 1).

[0179] Step 7), a material with a high thermal expansion coefficient (for example, a deposited metal aluminum film) is made on the insulating layer 5 as the first structural layer 6, such as Figure 5 As shown in g.

[0180] Step 8), use KOH or TMAH to wet etch the bottom of the substrate 1 to the deep silicon etch stop layer 8.

[0181] Step 9), front-side patterning etching is performed on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape.

[0182] Finally, the electrothermal MEMS driving arm is released to complete the production of the electrothermal MEMS driving arm, wherein step 8) and step 9) can be interchanged, such as Figure 5 h.

[0183] When the electrothermal MEMS driving arm is used, it is necessary to ensure that the voltage of the heating resistor layer 4 is higher than the voltage of the deep silicon etching stop layer 8 so that the formed PN junction is reverse biased.

[0184] The material of the substrate 1 may be high-resistance silicon, P-type silicon or N-type silicon. When the substrate 1 is P-type silicon, the doping concentration is relatively low.

[0185] In addition, the deep silicon etch stop layer 8 formed in step 2) and step 3) can be grown on the upper layer of the substrate 1 by epitaxy, such as Figure 5 As shown in i.

[0186] Example 4

[0187] like Figure 6 As shown, the difference between this embodiment and embodiment 3 is that the deep silicon etch stop layer 8 serves as both the second structural layer 7 and the heating resistor layer 4, and the structure is simpler than that of embodiment 3.

[0188] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprises a heating resistor layer 4, a first structure layer 6, a second structure layer 7, and an insulating layer 5 between the first structure layer 6 and the second structure layer 7, characterized in that it comprises the following steps.

[0189] Step 1), select high-resistance silicon as substrate 1.

[0190] Step 2), patterning is performed on the substrate 1 (i.e., photoresist is uniformly coated on the substrate 1, and then photolithography is performed) to form a mask pattern as a P-type ion doped region, such as Figure 6 As shown in a.

[0191] Among them, this step 2) is an optional step, that is, after patterning, what is doped in step 3) is the P-type ion doped area; if not patterned, what is doped in step 3) is the surface of the substrate 1.

[0192] Step 3), use an implantation method or a diffusion method to heavily dope the surface of the substrate 1 or the P-type ion doped area with P-type ions to form a deep silicon etch stop layer 8, which serves as both the second structural layer 7 and the heating resistor layer 4. Figure 6 As shown in b.

[0193] Step 4), remove the mask (ie, remove the photoresist 2), and make an insulating material (eg, deposit a SiO2 layer) on the heating resistor layer 4 as an insulating layer 5, such as Figure 6 c. At this point, via holes and metal leads can be made, and the making method is the same as step 4 in embodiment 1).

[0194] Step 5), a material with a high thermal expansion coefficient (for example, a deposited metal aluminum film) is made on the insulating layer 5 as the first structural layer 6, such as Figure 6 As shown in d.

[0195] Step 6), etching the bottom of the substrate 1 to the heating resistor layer 4.

[0196] Step 7), the upper part of the substrate 1 is subjected to front patterning etching according to the pre-designed MEMS driving arm shape.

[0197] Finally, the electrothermal MEMS driving arm is released to complete the production of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged, such as Figure 6 As shown in e.

[0198] The material of the substrate 1 can be high-resistance silicon, P-type silicon or N-type silicon. When the substrate 1 is N-type silicon, the voltage of the substrate 1 must be higher than the voltage of the deep silicon etch stop layer 8 to reverse bias the formed PN junction.

[0199] Example 5

[0200] The difference between this embodiment and embodiment 3 is that there is no insulating layer 5 .

[0201] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps.

[0202] Step 1), select high-resistance silicon as substrate 1.

[0203] Step 2), patterning is performed on the substrate 1 (i.e., photoresist is uniformly coated on the substrate 1, and then photolithography is performed) to form a mask pattern as a P-type ion doped region, such as Figure 7 As shown in a.

[0204] Among them, this step 2) is an optional step, that is, after patterning, what is doped in step 3) is the P-type ion doped area; if not patterned, what is doped in step 3) is the surface of the substrate 1.

[0205] Step 3), use an implantation method or a diffusion method to perform P-type ion heavy doping on the surface of the substrate 1 or the P-type ion doped area to form a deep silicon etching stop layer 8 as the second structure layer 7, such as Figure 7 As shown in b.

[0206] Step 4), mask and photolithography are performed on the deep silicon etch stop layer 8 to leave an N-type ion doped area, such as Figure 7 As shown in c.

[0207] Step 5), N-type ions are doped into the P-type ion doped area according to the pre-designed conductive loop pattern 3 to form N-type silicon, which is used as the heating resistor layer 4. Figure 7 As shown in d.

[0208] Step 6), make an insulating material with a high thermal expansion coefficient as the first structural layer 6 on the upper layer of the heating resistor layer 4, such as Figure 7 As shown in e.

[0209] Step 7), etching the bottom of the substrate 1 to the deep silicon etch stop layer 8.

[0210] Step 8), front-side patterning etching is performed on the upper part of the substrate 1 according to the pre-designed MEMS driving arm shape.

[0211] Finally, the electrothermal MEMS driving arm is released to complete the production of the electrothermal MEMS driving arm. Step 7) and step 8) can be interchanged. Figure 7 f.

[0212] When the electrothermal MEMS driving arm is used, it is necessary to ensure that the voltage of the heating resistor layer 4 is higher than the voltage of the deep silicon etching stop layer 8 so that the formed PN junction is reverse biased.

[0213] The material of the substrate 1 may be high-resistance silicon, P-type silicon or N-type silicon. When the substrate 1 is P-type silicon, the doping concentration is relatively low.

[0214] Example 6

[0215] The difference between this embodiment and embodiment 4 is that there is no insulating layer 5 .

[0216] A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm at least comprising a heating resistor layer 4, a first structural layer 6, and a second structural layer 7, characterized in that it comprises the following steps.

[0217] Step 1), select high-resistance silicon as substrate 1.

[0218] Step 2), patterning is performed on the substrate 1 (i.e., photoresist is uniformly coated on the substrate 1, and then photolithography is performed) to form a mask pattern as a P-type ion doped region, such as Figure 8 As shown in a.

[0219] Among them, this step 2) is an optional step, that is, after patterning, what is doped in step 3) is the P-type ion doped area; if not patterned, what is doped in step 3) is the surface of the substrate 1.

[0220] Step 3), use an implantation method or a diffusion method to perform P-type ion re-doping on the P-type ion doped region to form a deep silicon etch stop layer 8, which serves as both the second structural layer 7 and the heating resistor layer 4. Figure 8 As shown in b.

[0221] Step 4), remove the mask (ie remove the photoresist 2), and make an insulating material with a high thermal expansion coefficient on the upper layer of the heating resistor layer 4 as the first structural layer 6.

[0222] Step 5), etching the bottom of the substrate 1 to the heating resistor layer 4.

[0223] Step 6), the upper part of the substrate 1 is patterned and etched in the front side according to the pre-designed MEMS driving arm shape, and finally the electrothermal MEMS driving arm is released, thereby completing the manufacture of the electrothermal MEMS driving arm.

[0224] The material of the substrate 1 can be high-resistance silicon, P-type silicon or N-type silicon. When the substrate 1 is N-type silicon, the voltage of the substrate 1 must be higher than the voltage of the deep silicon etch stop layer 8 to reverse bias the formed PN junction.

[0225] When etching the substrate 1 in step 8 in Example 3), step 6 in Example 4), step 7 in Example 5), and step 5 in Example 6 of the present application, an electrochemical etching method can be used to achieve automatic stopping. The substrate 1 can be N-type, P-type or high-resistance silicon; when the substrate is N-type, the upper silicon layer is P-type, forming a PN junction; when the substrate is P-type, the upper silicon layer is N-type, forming a PN junction; when the substrate is high-resistance silicon, the upper silicon layer can be N-type or P-type; thereafter, the substrate is electrochemically etched, and the etching will automatically stop on the upper silicon layer.

Claims

1. A method for manufacturing an electrothermal MEMS driving arm, wherein the electrothermal MEMS driving arm comprises at least a heating resistor layer (4), a first structural layer (6), a second structural layer (7), and an insulating layer (5) between the first structural layer (6) and the second structural layer (7), wherein the method comprises: The steps include: Step 1), selecting high-resistance silicon as the substrate (1); Step 2), patterning is performed on the substrate (1) to form a mask of a pre-designed conductive circuit pattern (3); Step 3), doping the substrate (1) by an implantation method or a diffusion method to form a conductive loop, which serves as a heating resistor layer (4); Step 4), making an insulating material on the heating resistor layer (4) as an insulating layer (5); Step 5), making a material with a high thermal expansion coefficient on the insulating layer (5) as the first structural layer (6); Step 6), etching the bottom of the substrate (1), leaving high-resistance silicon of a set thickness as the second structural layer (7); Step 7), performing front patterning etching on the upper part of the substrate (1) according to the pre-designed MEMS driving arm shape; Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

2. A method for manufacturing an electrothermal MEMS drive arm, the electrothermal MEMS drive arm comprising at least a heating resistor layer (4), a first structural layer (6), and a second structural layer (7), characterized in that The steps include: Step 1), selecting high-resistance silicon as the substrate (1); Step 2), patterning is performed on the substrate (1) to form a mask of a pre-designed conductive circuit pattern (3); Step 3), doping the substrate (1) by an implantation method or a diffusion method to form a conductive loop, which serves as a heating resistor layer (4); Step 4), making an insulating material with a high thermal expansion coefficient as a first structural layer (6) on the upper layer of the heating resistor layer (4); Step 5), etching the bottom of the substrate (1), leaving high-resistance silicon of a set thickness as the second structural layer (7); Step 6), performing front patterning etching on the upper part of the substrate (1) according to the pre-designed MEMS driving arm shape; Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

3. A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm comprising at least a heating resistor layer (4), a first structural layer (6), a second structural layer (7), and an insulating layer (5) between the first structural layer (6) and the second structural layer (7), characterized in that The steps include: Step 1), selecting high-resistance silicon as the substrate (1); Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate (1) with P-type ions to form a deep silicon etching stop layer (8) as the second structural layer (7); Step 3), masking and photolithography are performed on the deep silicon etch stop layer (8) to leave an N-type ion doped area; Step 4), doping N-type ions into the interior of the P-type ion doped region according to the pre-designed conductive loop pattern (3), forming N-type silicon as a heating resistor layer (4); Step 5), removing the mask, and making an insulating material on the heating resistor layer (4) as an insulating layer (5); Step 6), making a material with a high thermal expansion coefficient on the insulating layer (5) as the first structural layer (6); Step 7), etching the bottom of the substrate (1) to the deep silicon etch stop layer (8); Step 8), performing front patterning etching on the upper part of the substrate (1) according to the pre-designed MEMS driving arm shape; Finally, the electrothermal MEMS driving arm is released to complete the production of the electrothermal MEMS driving arm, wherein step 7) and step 8) can be interchanged.

4. A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm comprising at least a heating resistor layer (4), a first structural layer (6), a second structural layer (7), and an insulating layer (5) between the first structural layer (6) and the second structural layer (7), characterized in that The steps include: Step 1), selecting high-resistance silicon as the substrate (1); Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate (1) with P-type ions to form a deep silicon etch stop layer (8), wherein the deep silicon etch stop layer (8) serves as both the second structural layer (7) and the heating resistor layer (4); Step 3), removing the mask, and making an insulating material on the heating resistor layer (4) as an insulating layer (5); Step 4), making a material with a high thermal expansion coefficient on the insulating layer (5) as the first structural layer (6); Step 5), etching the bottom of the substrate (1) to the heating resistor layer (4); Step 6), performing front patterning etching on the upper part of the substrate (1) according to the pre-designed MEMS driving arm shape; Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 5) and step 6) can be interchanged.

5. A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm comprising at least a heating resistor layer (4), a first structural layer (6), and a second structural layer (7), characterized in that The steps include: Step 1), selecting high-resistance silicon as the substrate (1); Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate (1) with P-type ions to form a deep silicon etching stop layer (8) as the second structural layer (7); Step 3), masking and photolithography are performed on the deep silicon etch stop layer (8) to leave an N-type ion doped area; Step 4), doping N-type ions into the interior of the P-type ion doped region according to the pre-designed conductive loop pattern (3), forming N-type silicon as a heating resistor layer (4); Step 5), making an insulating material with a high thermal expansion coefficient as a first structural layer (6) on the upper layer of the heating resistor layer (4); Step 6), etching the bottom of the substrate (1) to the deep silicon etch stop layer (8); Step 7), performing front patterning etching on the upper part of the substrate (1) according to the pre-designed MEMS driving arm shape; Finally, the electrothermal MEMS driving arm is released to complete the manufacturing of the electrothermal MEMS driving arm, wherein step 6) and step 7) can be interchanged.

6. A method for manufacturing an electrothermal MEMS driving arm, the electrothermal MEMS driving arm comprising at least a heating resistor layer (4), a first structural layer (6), and a second structural layer (7), characterized in that The steps include: Step 1), selecting high-resistance silicon as the substrate (1); Step 2), using an implantation method or a diffusion method to heavily dope the surface of the substrate (1) with P-type ions to form a deep silicon etch stop layer (8), wherein the deep silicon etch stop layer (8) serves as both the second structural layer (7) and the heating resistor layer (4); Step 3), making an insulating material with a high thermal expansion coefficient as a first structural layer (6) on the upper layer of the heating resistor layer (4); Step 4), etching the bottom of the substrate (1) to the heating resistor layer (4); Step 5), front-side patterning etching is performed on the upper part of the substrate (1) according to the pre-designed MEMS driving arm shape, and finally the electrothermal MEMS driving arm is released, thereby completing the production of the electrothermal MEMS driving arm.

7. A method for manufacturing an electrothermal MEMS drive arm according to any one of claims 3 to 6, characterized in that The deep silicon etch stop layer (8) formed in step 2) can be grown on the upper layer of the substrate (1) in an epitaxial manner.

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