Inductor structure and method of forming the same

Abstract

A portion of this invention relates to an inductor structure and a method of forming the same, the inductor structure comprising: an etch stop layer disposed over an interconnect structure, the interconnect structure being overlaid on a substrate; a magnetic structure comprising a plurality of stacked layers disposed over the etch stop layer; the magnetic structure comprising a bottom layer wider than the top layer; a first conductive wiring and a second conductive wiring extending parallel to each other over the magnetic structure; the magnetic structure being configured to modify the magnetic field generated by the first conductive wiring and the second conductive wiring; and a patterning enhancement layer disposed between the bottom layer of the magnetic structure and the etch stop layer. The patterning enhancement layer has a first thickness, and the bottom layer of the magnetic structure has a second thickness less than the first thickness.

Description

Technical Field

[0001] Embodiments of the present invention relate to an inductor structure and a method for forming the same. Background Art

[0002] An integrated circuit (IC) is an assembly of electronic components located on a piece of semiconductor material. A widely used electronic component in integrated circuits is the inductor. An inductor is a passive component that stores electrical energy in a magnetic field when current flows through it. Inductors are multifunctional devices that can be used, among other things, in resistor-inductor (RL) filters, inductor-capacitor (LC) circuits, resistor-inductor-capacitor (RLC) circuits, power supplies, transformers, and many other circuit components. Summary of the invention

[0003] An embodiment of the present invention provides an inductor structure comprising: an etch stop layer, arranged on an interconnect structure, the interconnect structure overlying a substrate; a magnetic structure, comprising a plurality of stacked layers arranged on the etch stop layer, the magnetic structure comprising a bottom layer wider than a top layer; a first conductive wiring and a second conductive wiring, extending in parallel on the magnetic structure, wherein the magnetic structure is configured to modify the magnetic field generated by the first conductive wiring and the second conductive wiring; and a pattern enhancement layer, arranged between the bottom layer of the magnetic structure and the etch stop layer, wherein the pattern enhancement layer has a first thickness, and wherein the bottom layer of the magnetic structure has a second thickness less than the first thickness.

[0004] An embodiment of the present invention provides an inductor structure including: an interconnect structure disposed on a semiconductor substrate; a first etch stop layer arranged on the interconnect structure; a first magnetic structure disposed on the first etch stop layer, the first magnetic structure including a cobalt zinc tantalum layer located between a bottom tantalum layer and a top oxygen cobalt zinc tantalum layer; one or more conductive wirings disposed on the first magnetic structure and defining an inductor; and a pattern enhancement layer disposed between the bottom tantalum layer and the first etch stop layer.

[0005] An embodiment of the present invention provides a method for forming an inductor structure, comprising: forming a first pattern enhancement layer on a first etch stop layer; forming a magnetic structure on the first pattern enhancement layer, wherein the magnetic structure comprises an oxycobalt zinc tantalum (OCZT) material layer, a tantalum material layer, and a cobalt zinc tantalum (CZT) material layer, wherein the first pattern enhancement layer directly contacts one of the tantalum material layers; and removing a peripheral portion of the magnetic structure and a peripheral portion of the first pattern enhancement layer, wherein the magnetic structure and the first pattern enhancement layer are etched by the same etchant in a first etching process. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] When read in conjunction with the accompanying drawings, various aspects of the present invention are best understood from the following detailed description. It should be noted that, in accordance with standard practice in the industry, the various features are not drawn to scale. In fact, the size of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0007] Figure 1A to Figure 1B Cross-sectional views of some embodiments of an inductor structure are shown having a first pattern enhancement layer between a first etch stop layer and a first magnetic shielding structure.

[0008] Figures 2 to 4 Cross-sectional views of some additional embodiments of a first pattern enhancement layer between a first etch stop layer and a first magnetic shield structure are shown.

[0009] Figure 5 Cross-sectional views of some additional embodiments of an inductor structure are shown having a first pattern enhancement layer between a first etch stop layer and a first magnetic shield structure, and having a second pattern enhancement layer between a second etch stop layer and a second magnetic shield structure.

[0010] Figure 6 Cross-sectional views of some additional embodiments of inductor structures are shown having a first pattern enhancement layer below the first magnetic shield structure and a second magnetic shield structure having a center portion recessed below a topmost portion of the second magnetic shield structure.

[0011] Figure 7 Cross-sectional views of some additional embodiments of an inductor structure having a second pattern enhancement layer between a second magnetic shield structure and a second etch stop layer are shown, wherein the second pattern enhancement layer has a central portion recessed below a topmost portion of the second pattern enhancement layer.

[0012] Fig. 8A and Figure 8BVarious views of some embodiments of an inductor structure are shown having a first pattern enhancement layer and coupled to an interconnect structure through contact vias.

[0013] Figures 9 to 20 Cross-sectional views of some embodiments of methods of forming an inductor structure having a first pattern enhancement layer between a first etch stop layer and a first magnetic shield structure are shown.

[0014] Fig.21 Show Figures 9 to 20 Flowcharts of some embodiments of the method shown in .

[0015] [Explanation of Symbols]

[0016] 100A, 100B, 200, 300, 400, 500, 600, 700, 800B, 900, 1000, 1100A, 1100B, 1100C, 1100D, 1100E, 1100F, 1100G, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000: Cross-sectional view

[0017] 102: First passivation layer

[0018] 104: First barrier layer

[0019] 106: First etch stop layer

[0020] 108: First pattern enhancement layer

[0021] 110: First magnetic structure

[0022] 110a: First layer group / layer group

[0023] 110b: Second layer group / layer group

[0024] 110c: Third layer group / layer group

[0025] 110L: Bottom layer

[0026] 110t: Top layer

[0027] 112: Second barrier layer

[0028] 114: First conductive wiring

[0029] 116: Second conductive wiring

[0030] 118: Dielectric Structure

[0031] 118c, 126c, 508c: center part

[0032] 118t, 126t, 508t: the top part

[0033] 120: First isolation layer

[0034] 122: The third barrier layer

[0035] 124: Second etch stop layer

[0036] 126: Second magnetic structure

[0037] 128: Substrate

[0038] 130: Semiconductor devices

[0039] 130a: Source / drain region

[0040] 130b: Gate electrode

[0041] 130c: Gate dielectric layer

[0042] 140: Inner connection structure

[0043] 142: Internal wiring

[0044] 144: Internal connecting hole

[0045] 146: Interconnect dielectric structure

[0046] 162: Tantalum layer

[0047] 164: Cobalt zinc tantalum (CZT) layer

[0048] 166: Oxygen-CZT (OCZT) layer

[0049] 302: First interface

[0050] 304: Tantalum layer

[0051] 508: Second pattern enhancement layer

[0052] 508s: Outermost wall

[0053] 800A: Top view

[0054] 802: Internal passivation layer

[0055] 804a: first contact hole

[0056] 804b: Second contact hole

[0057] 806a: third contact through hole

[0058] 806b: fourth contact through hole

[0059] 808: Contact layer

[0060] 812: Isolation Structure

[0061] 902: First pattern reinforcement material

[0062] 904: Tantalum material

[0063] 904b: Bottom Tantalum Layer

[0064] 904i: intermediate tantalum layer

[0065] 904t: Top tantalum layer

[0066] 906: Cobalt Zinc Tantalum (CZT) material

[0067] 906b: Bottom CZT layer

[0068] 906i: Middle CZT layer

[0069] 906t: Top CZT layer

[0070] 908: Oxygen-CZT (OCZT) materials

[0071] 908b: Bottom OCZT layer

[0072] 908i: Middle OCZT layer

[0073] 908t: Top OCZT layer

[0074] 1002: First mask layer

[0075] 1102: Wet Etchant

[0076] 1104: First Area

[0077] 1106: OCZT residue

[0078] 1108: Second Area

[0079] 1202: Seed layer

[0080] 1802: Second pattern reinforcement material

[0081] 2100: Methods

[0082] 2102, 2104, 2106, 2108, 2110, 2112, 2114, 2116, 2118: Action

[0083] A: Frame

[0084] BB': Line

[0085] t1: first thickness

[0086] t2: second thickness

[0087] t3: third thickness

[0088] t4: fourth thickness

[0089] t5: fifth thickness

[0090] w1: first width

[0091] w2: second width

[0092] w3: third width

[0093] w4: fourth width DETAILED DESCRIPTION

[0094] The following disclosure provides many different embodiments or examples for implementing the different features of the provided subject matter. Specific examples of components and arrangements are set forth below to simplify the present invention. Of course, these are merely examples and are not intended to be limiting. For example, the following description in which a first feature is formed on or on a second feature may include an embodiment in which the first feature and the second feature are formed to be in direct contact, and may also include an embodiment in which an additional feature may be formed between the first feature and the second feature so that the first feature and the second feature may not be in direct contact. In addition, the present invention may reuse reference numbers and / or letters in various examples. This repetition is for the purpose of brevity and clarity, rather than indicating the relationship between the various embodiments and / or configurations discussed by itself.

[0095] Additionally, for ease of description, spatially relative terms such as "beneath," "below," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or feature to another (other) element or feature as shown in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0096] Inductors with useful inductance often consume a large area on an integrated circuit. Therefore, to avoid taking up valuable space, the inductor structure can be formed on top of an interconnect structure located on a semiconductor substrate. In some embodiments, such an inductor structure includes an etch stop layer overlying a passivation layer located on the interconnect structure. The magnetic structure is disposed on the etch stop layer. The first conductive wire and the second conductive wire extend parallel to each other along an upper surface of the magnetic structure. A dielectric structure can overlie the first conductive wire and the second conductive wire and the magnetic structure so that the first conductive wire and the second conductive wire are spaced apart from each other and covered by the dielectric structure.

[0097] During operation, the first conductive wire and the second conductive wire may each be coupled to a control circuit system configured to apply a first current to the first conductive wire in a first direction and a second current to the second conductive wire in a second direction. Due to the "right-hand rule", the first magnetic field and the second magnetic field may be induced around the first conductive wire and the second conductive wire, respectively, and give the inductor structure a measurable inductance. In some embodiments, the magnetic structure is configured to concentrate the first magnetic field and the second magnetic field near the first conductive wire and the second conductive wire and away from the underlying interconnect structure.

[0098] In some embodiments, a magnetic structure may be formed by depositing a tantalum layer on an etch stop layer, depositing a cobalt zinc tantalum (CZT) layer on the tantalum layer, and further depositing an oxygen-CZT (OCZT) layer on the CZT layer. A first wet etching process may be used to remove peripheral portions of these layers according to a mask layer. However, during the first wet etching process, since the OCZT layer has a slower etching rate than the CZT layer and the tantalum layer, residues from the OCZT layer may be generated and adhere to the etch stop layer. In some embodiments, the OCZT residues may be detected as cobalt oxygen (CoO) precipitates by chemical analysis (e.g., energy dispersive X-ray spectroscopy (EDX) analysis). A dry etching process may then be performed to remove the peripheral portion of the etch stop layer, but since the OCZT residue is resistant to the dry etching process, at least some of the OCZT residue (e.g., CoO precipitates) and the underlying etch stop layer may remain. The OCZT residue may negatively affect the effectiveness of the magnetic structure and cause leakage of the first magnetic field and the second magnetic field.

[0099] Various embodiments of the present invention present an inductor structure comprising a first pattern enhancement layer located between a magnetic structure and a first etch stop layer. The magnetic structure may include several layer groups, the several layer groups respectively including a tantalum layer, a CZT layer arranged on the tantalum layer, and an oxygen-CZT (OCZT) layer arranged on the CZT layer. The first pattern enhancement layer may be thicker than the lowest layer of the magnetic structure and provide more space and time for removing OCZT residues during patterning of the magnetic structure. For example, during a first wet etching process, when the topmost OCZT layer is exposed to the first wet etching process, OCZT residues (e.g., CoO precipitates) are generated. When the bottommost OCZT layer is exposed to the first wet etching process, the OCZT residues from the topmost OCZT layer are almost completely or completely removed, but OCZT residues from the bottommost OCZT layer may be generated. In order to remove the OCZT residue from the bottommost OCZT layer and prevent the OCZT residue from contacting the first etch stop layer, the first pattern enhancement layer provides another barrier layer between the OCZT residue and the first etch stop layer. Therefore, when the first pattern enhancement layer is removed from the first etch stop layer, the OCZT residue has been completely removed. Therefore, the first pattern enhancement layer and the first wet etching process can effectively remove the OCZT residue before the OCZT residue contacts the first etch stop layer, so that the inductor structure can reliably concentrate the first magnetic field and the second magnetic field induced by the first conductive wiring and the second conductive wiring, respectively.

[0100] Figure 1A A cross-sectional view 100A of some embodiments of an inductor structure including a first pattern enhancement layer is shown.

[0101] The inductor structure in cross-sectional view 100A includes a first passivation layer 102 and a first barrier layer 104 disposed on an interconnect structure 140. In some embodiments, the interconnect structure 140 includes a network of interconnect wires 142 and interconnect vias 144 embedded in an interconnect dielectric structure 146. In some embodiments, the interconnect structure 140 is disposed on a substrate 128 and coupled to a semiconductor device 130. In some embodiments, the semiconductor device 130 may be, for example, a metal oxide semiconductor field-effect transistor (MOSFET) including source / drain regions 130a disposed in the substrate 128 and a gate electrode 130b disposed on the substrate 128. The gate electrode 130b may be separated from the substrate 128 by a gate dielectric layer 130c. The semiconductor device 130 and the interconnect structure 140 may be coupled to the first conductive wire 114 and / or the second conductive wire 116 to operate the inductor structure.

[0102] The first conductive wire 114 and the second conductive wire 116 are disposed over the first magnetic structure 110, and the first magnetic structure 110 may be disposed over the first etch stop layer 106. In some embodiments, the first pattern enhancement layer 108 may be disposed between the first etch stop layer 106 and the first magnetic structure 110. In some embodiments, the first pattern enhancement layer 108 may be directly below the first magnetic structure 110 and may be narrower than the bottommost surface of the first magnetic structure 110. Thus, the first pattern enhancement layer 108 may have been etched much more or faster in the lateral direction than the first magnetic structure 110. The first pattern enhancement layer 108 may include a material that is soluble in the same wet etchant as the first magnetic structure 110. For example, in some embodiments, the wet etchant may include a mixture of nitric acid and hydrofluoric acid, and the first pattern enhancement layer 108 may include tantalum, silicon nitride, titanium, tungsten, zirconium, nickel, silicon germanium, tin, niobium, vanadium, or indium antimony.

[0103] In some embodiments, the second barrier layer 112 isolates the first conductive wire 114 and the second conductive wire 116 from the first magnetic structure 110. In addition, the dielectric structure 118 may overlie the first conductive wire 114 and the second conductive wire 116 and the first magnetic structure 110, so that the first conductive wire 114 and the second conductive wire 116 are spaced apart from each other and covered by the dielectric structure 118. In some embodiments, the dielectric structure 118 may have a substantially flat top surface. The first isolation layer 120 overlies the dielectric structure 118 and the first magnetic structure 110. The third barrier layer 122 may overlie the first isolation layer 120 and laterally surround the first magnetic structure 110 and the first pattern enhancement layer 108. The second etch stop layer 124 may overlie the third barrier layer 122, and the second magnetic structure 126 may overlie the second etch stop layer 124.

[0104] During operation of the inductor structure, a first current may be applied to the first conductive wire 114, and a second current may be applied to the second conductive wire 116, by, for example, the semiconductor device 130. A first magnetic field and a second magnetic field may be induced around the first conductive wire 114 and the second conductive wire 116, respectively. The first magnetic structure 110 and the second magnetic structure 126 may shield the first magnetic field and the second magnetic field to concentrate the magnetic flux of the inductor structure near the first conductive wire 114 and the second conductive wire 116.

[0105] The first pattern enhancement layer 108 is configured to delay exposure of the first etch stop layer 106 during an etching process for patterning the first magnetic structure 110. By delaying exposure of the first etch stop layer 106, the etching process has time to remove residue from the first magnetic structure 110 before exposing the first etch stop layer 106, thereby preventing residue from accumulating from the first magnetic structure 110 onto the first etch stop layer 106. By preventing residue from accumulating from the first magnetic structure 110 onto the first etch stop layer 106, the reliability of the first magnetic structure 110 in concentrating magnetic flux near the first conductive wire 114 and the second conductive wire 116 during operation is increased.

[0106] Figure 1B Shows that Figure 1A Some embodiments of the first magnetic structure 110 and the first pattern enhancement layer 108 in the frame A of the cross-sectional view 100A correspond to the cross-sectional view 100B.

[0107] In some embodiments, the first magnetic structure 110 may include a first layer group 110a and a second layer group 110b. In some embodiments, the first layer group 110a and / or the second layer group 110b include a tantalum layer 162, a cobalt zinc tantalum (CZT) layer 164 disposed on the tantalum layer 162, and an oxygen-CZT (OCZT) layer 166 disposed on the CZT layer 164. In some embodiments, the first magnetic structure 110 may have an overall ladder shape. In some embodiments, the bottommost layer 110L of the first magnetic structure 110 (e.g., the bottommost tantalum layer 162) is wider than the topmost layer 110t of the first magnetic structure 110 (e.g., the topmost OCZT layer 166).

[0108] The first pattern enhancement layer 108 may be disposed between the tantalum layer 162 and the first etch stop layer 106. The tantalum layer 162 directly contacting the first pattern enhancement layer 108 does not extend below the top surface of the first pattern enhancement layer 108. In some embodiments, the first pattern enhancement layer 108 has a first thickness t1 in a range between approximately 300 angstroms and approximately 1000 angstroms. In some embodiments, the tantalum layer 162 directly contacting the first pattern enhancement layer 108 may have a second thickness t2 in a range between, for example, approximately 15 angstroms and approximately 50 angstroms. Thus, the first thickness t1 may be greater than the second thickness t2. The first pattern enhancement layer 108 may be thicker than the tantalum layer 162 to provide more time to remove OCZT residues during the first wet etching process before exposing the first etch stop layer 106 (see FIG. 11A to FIG. 11G ).

[0109] In some embodiments, the first pattern enhancement layer 108 may have an outermost sidewall that is curved from the cross-sectional view 100B.

[0110] In addition, the first etch stop layer 106 has a first width w1; the lowermost layer 110L of the first magnetic structure 110 has a bottom surface having a second width w2; the first pattern enhancement layer 108 has a bottom surface having a third width w3; and the first pattern enhancement layer 108 has a top surface having a fourth width w4. In some embodiments, the first width w1 is greater than the second width w2, the third width w3, and the fourth width w4. In addition, in some embodiments, the second width w2 is greater than the third width w3. In some embodiments, the second width w2 is also greater than the fourth width w4. Since in some embodiments, the first pattern enhancement layer 108 has a higher etching rate than the tantalum layer 162, the second width w2 is greater than the third width w3 and / or the fourth width w4, so that the first pattern enhancement layer 108 does not significantly increase the time of the first wet etching process and reduce manufacturing efficiency.

[0111] Figure 2 Show Figure 1B 200 of an alternative embodiment of the present invention, wherein the second width w2 of the bottom surface of the lowermost layer 110L of the first magnetic structure 110 is approximately equal to the fourth width w4 of the top surface of the first pattern enhancement layer 108. In such an embodiment, the first pattern enhancement layer 108 and the lowermost layer 110L of the first magnetic structure 110 may have approximately equal etching rates. In such an embodiment, since the first pattern enhancement layer 108 does not have a higher etching rate than the lowermost layer 110L of the first magnetic structure 110 (the bottom one tantalum layer 162), there is more time to remove the OCZT residue during the first wet etching process before the first etch stop layer 106 is exposed when the first pattern enhancement layer 108 is removed.

[0112] Figure 3 Show Figure 1B FIG. 3 is a cross-sectional view 300 of another alternative embodiment in which both the first pattern enhancement layer 108 and the tantalum layer 162 include tantalum.

[0113] In such an embodiment, since the first interface 302 between the tantalum layer 162 and the first pattern enhancement layer 108 may not be visible (as shown by the dotted line), the lowermost layer 110L of the first magnetic structure 110 may appear to include the tantalum layer 162 and the first pattern enhancement layer 108. In such an embodiment, the presence of the first pattern enhancement layer 108 can be identified by the lowermost layer 110L of the first magnetic structure 110 having a third thickness t3, which may be the maximum thickness of the lowermost layer 110L. The third thickness t3 may be greater than the second thickness t2 of the upper tantalum layer 304. The upper tantalum layer 304 is located above the lowermost layer 110L of the first magnetic structure 110.

[0114] Furthermore, in some embodiments, the first magnetic structure 110 and / or the first pattern enhancement layer 108 may have a substantially flat outermost wall.

[0115] Figure 4 Show Figure 1B A cross-sectional view 400 of yet another alternative embodiment of FIG. 1 , wherein the first pattern enhancement layer 108 is wider than the first magnetic structure 110 .

[0116] In some embodiments, the first pattern enhancement layer 108 may have a slower etching rate than the lowermost layer 110L of the first magnetic structure 110 to increase the time to remove OCZT residues (e.g., CoO precipitates) during the first wet etching process before exposing the first etch stop layer 106. In such an embodiment, the third width w3 and the fourth width w4 of the first pattern enhancement layer 108 may be greater than the second width w2 of the lowermost layer 110L of the first magnetic structure 110.

[0117] Figure 5 A cross-sectional view 500 of some embodiments of an inductor structure having a first pattern enhancement layer and a second pattern enhancement layer is shown.

[0118] In some embodiments, the inductor structure further has a second pattern enhancement layer 508 disposed between the second magnetic structure 126 and the second etch stop layer 124. In some embodiments, the second pattern enhancement layer 508 may have an outermost wall 508s directly under the second magnetic structure 126. In other embodiments (not shown), the second pattern enhancement layer 508 may have an outermost wall 508s not directly under the second magnetic structure 126. The second pattern enhancement layer 508 may prevent residues from the second magnetic structure 126 from contacting and adhering to the second etch stop layer 124 during the third wet etching process to pattern the second magnetic structure 126.

[0119] In some embodiments, the second magnetic structure 126 may include a structure different from the first magnetic structure 110. For example, in some embodiments, the second magnetic structure 126 may include, for example, three layer groups ( Fig. 20 110a, 110b, 110c), and the first magnetic structure 110 may include, for example, two layer groups ( Figure 1B 110a, 110b). In other embodiments, the first magnetic structure 110 and the second magnetic structure 126 may include different materials from each other. Therefore, in some embodiments, the first pattern enhancement layer 108 and the second pattern enhancement layer 508 may include different materials and / or have different thicknesses. In other embodiments, it should be understood that the first pattern enhancement layer 108 and the second pattern enhancement layer 508 may include the same material and / or have approximately the same thickness.

[0120] Figure 6 Shown as Figure 1ACross-sectional view 600 of some alternative embodiments of the inductor structure shown in cross-sectional view 100A.

[0121] In some embodiments, the dielectric structure 118 may have an upper surface. A central portion 118c of the upper surface is recessed below a topmost portion 118t of the upper surface of the dielectric structure 118. The topmost portion 118t of the upper surface of the dielectric structure 118 may overlie the first conductive wiring 114 and the second conductive wiring 116, and the central portion 118c of the upper surface of the dielectric structure 118 may overlie the space between the first conductive wiring 114 and the second conductive wiring 116. Therefore, the first isolation layer 120, the third barrier layer 122, the second etch stop layer 124, and the second magnetic structure 126 may also have an upper surface having a central portion recessed below the topmost portion. For example, in some embodiments, the second magnetic structure 126 may have an upper surface having a central portion 126c recessed below a topmost portion 126t of the upper surface of the second magnetic structure 126. Therefore, in some embodiments, the central portion 126c of the upper surface of the second magnetic structure 126 may directly overlie the central portion 118c of the upper surface of the dielectric structure 118. Similarly, in some embodiments, the topmost portion 126t of the upper surface of the second magnetic structure 126 may directly overlie the topmost portion 118t of the upper surface of the dielectric structure 118.

[0122] Figure 7 Shown as Figure 5 Cross-sectional views 700 of some alternative embodiments of the inductor structure shown in cross-sectional view 500 .

[0123] As shown in the cross-sectional view 700, the dielectric structure 118 may have an upper surface having a central portion 118c that is recessed below a topmost portion 118t of the upper surface of the dielectric structure 118. In some embodiments, the second pattern enhancement layer 508 may be disposed between the second magnetic structure 126 and the second etch stop layer 124. Therefore, in some embodiments, the second pattern enhancement layer 508 may have an upper surface in which a central portion 508c of the upper surface of the second pattern enhancement layer 508 is recessed below a topmost portion 508t of the upper surface of the second pattern enhancement layer 508. In such an embodiment, the central portion 508c of the upper surface of the second pattern enhancement layer 508 may directly overlie the central portion 118c of the upper surface of the dielectric structure 118, and the topmost portion 508t of the upper surface of the second pattern enhancement layer 508 may directly overlie the topmost portion 118t of the upper surface of the dielectric structure 118.

[0124] Fig. 8A A top view 800A of some embodiments of an inductor structure is shown, wherein a first conductive wire and a second conductive wire are coupled to a contact via.

[0125] In some embodiments, the first conductive wire 114 and the second conductive wire 116 are not visible from the top view 800A, and therefore, in Fig. 8A In some embodiments, the first conductive wire 114 and the second conductive wire 116 are partially covered by the second magnetic structure 126. Under the second magnetic structure 126, the first conductive wire 114 and the second conductive wire 116 may extend parallel to each other. In addition, in some embodiments, the interconnect passivation layer 802 may overlie the interconnect structure ( Figure 1A 140). In some embodiments, a portion of the first conductive wiring 114 and a portion of the second conductive wiring 116 may be embedded below the interconnect passivation layer 802. In some embodiments, the first conductive wiring 114 may be coupled to the first contact via 804a and the second contact via 804b. The second conductive wiring 116 may be coupled to the third contact via 806a and the fourth contact via 806b. Therefore, during operation, a first current may be applied to the first contact via 804a and the second contact via 804b to induce a first magnetic field in the first conductive wiring 114, and a second current may be applied to the third contact via 806a and the fourth contact via 806b to induce a second magnetic field in the second conductive wiring 116. The second magnetic structure 126 and the first magnetic structure ( Figure 1A 110) can effectively concentrate the magnetic flux near the first conductive wiring 114 and the second conductive wiring 116.

[0126] Figure 8B Shown along Fig. 8A A cross-sectional view 800B of some embodiments of an inductor structure along line BB'.

[0127] In some embodiments, the portions of the first conductive wiring 114 and the second conductive wiring 116 embedded in the internal passivation layer 802 are not visible in the cross-sectional view 800B, as shown by the dotted lines. In some embodiments, the internal passivation layer 802 may include, for example, silicon dioxide, silicon nitride, a polyimide compound, or other suitable materials. In addition, in some embodiments, the contact layer 808 is located below the second contact via 804b and the fourth contact via 806b. Therefore, in some embodiments, a portion of the first conductive wiring 114 is embedded in the internal passivation layer 802 and is in electrical contact with one of the contact layer 808 and the second contact via 804b, and a portion of the second conductive wiring 116 is embedded in the internal passivation layer 802 and is in electrical contact with one of the contact layer 808 and the fourth contact via 806b. In other embodiments, the second contact via 804b and the fourth contact via 806b may be omitted. In some embodiments, the contact layer 808 may include, for example, aluminum, copper, etc. The contact layer 808 may be coupled to the semiconductor device 130 via the interconnect structure 140 .

[0128] In some embodiments, an isolation structure 812 may be embedded in the substrate 128 and between each of the semiconductor devices 130 for electrical isolation between each semiconductor device 130. In some embodiments, the semiconductor device 130 for controlling current in the first conductive wire 114 and the second conductive wire 116 may be or include one or more of the following: a low voltage (e.g., 1.8V to 3.3V) device and a high voltage device.

[0129] Fig. 9 , Fig.10 , FIG. 11A to FIG. 11G as well as Figures 12 to 20 Cross-sectional views 900, 1000, 1100A-1100G, and 1200-2000 illustrate some embodiments of a method of forming an inductor structure having a first pattern enhancement layer disposed between a first magnetic structure and a first etch stop layer. Fig. 9 , Fig.10 , FIG. 11A to FIG. 11G as well as Figures 12 to 20 This is an explanation of one method, but it should be understood that Fig. 9 , Fig.10 , FIG. 11A to FIG. 11G as well as Figures 12 to 20 The structure disclosed in is not limited to such a method, but can exist independently as a structure independent of the method.

[0130] like Fig. 9 As shown in the cross-sectional view 900 of , in some embodiments, an interconnect structure 140 may be formed on the substrate 128. The interconnect structure 140 may include an interconnect wiring 142 and an internal communication hole 144 embedded in an interconnect dielectric structure 146. In some embodiments, the interconnect wiring 142 and the internal communication hole 144 may include copper, tungsten, aluminum, etc. The interconnect structure 140 may be coupled to a semiconductor device 130 integrated on the substrate 128. In some embodiments, the semiconductor device 130 may be or include a metal oxide semiconductor field effect transistor (MOSFET). The MOSFET includes a source / drain region 130a located in the substrate 128. The semiconductor device 130 may also include a gate electrode 130b arranged on a gate dielectric layer 130c located on the substrate 128.

[0131] In some embodiments, a first passivation layer 102 is formed on the interconnect structure 140, and the first passivation layer 102 may include, for example, a nitride (e.g., silicon nitride), an oxide (e.g., silicon dioxide), etc. A first barrier layer 104 may be formed on the first passivation layer 102, and the first barrier layer 104 may include, for example, silicon nitride, silicon carbide, etc. Therefore, in some embodiments, the first barrier layer 104 may include the same material as the first passivation layer 102. In other embodiments, the first barrier layer 104 may include a different material from the first passivation layer 102. In some embodiments, the first passivation layer 102 and the first barrier layer 104 may be deposited using a deposition process (e.g., chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), etc.).

[0132] A first etch stop layer 106 is deposited over the first barrier layer 104, and the first etch stop layer 106 may include, for example, a metal oxide (e.g., tantalum oxide, titanium oxide), another suitable etch stop material, etc. In some embodiments, a method for forming the first etch stop layer 106 may include: forming a metal material (e.g., tantalum) over the first barrier layer 104; and then performing a thermal annealing process (e.g., using water (H2O)) to convert the metal material into a metal oxide.

[0133] A first pattern enhancement material 902 may be formed over the first etch stop layer 106. The first pattern enhancement material 902 may form a layer having a first thickness t1 in a range between, for example, approximately 300 angstroms and approximately 1000 angstroms. A first magnetic structure 110 including a first layer group 110a, a second layer group 110b, and a third layer group 110c may be deposited over the first pattern enhancement material 902. The first layer group 110a may include a tantalum material 904 deposited over the first pattern enhancement material 902, a cobalt zinc tantalum (CZT) material 906 deposited over the tantalum material 904, and an oxy-CZT (OCZT) material 908 deposited over the CZT material 906. In some embodiments, the tantalum material 904 includes tantalum, the CZT material 906 includes CZT, and the OCZT material 908 includes OCZT.

[0134] In some embodiments, the tantalum material 904 may form a layer having a second thickness t2 that is less than the first thickness t1. For example, in some embodiments, the second thickness t2 is in a range between approximately 15 angstroms and approximately 50 angstroms. In some embodiments, the CZT material 906 may form a layer having a fourth thickness t4 that is in a range between approximately 4000 angstroms and approximately 5000 angstroms. In some embodiments, the OCZT material 908 may form a layer having a fifth thickness t5 that is in a range between approximately 150 angstroms and approximately 500 angstroms. In other embodiments, the fifth thickness t5 may be greater than 500 angstroms. Therefore, the fourth thickness t4 may be greater than the first thickness t1, the second thickness t2, and the fifth thickness t5.

[0135] The amount of oxygen in the OCZT material 908 and / or the fifth thickness t5 of the OCZT material 908 may affect the resistance of the first magnetic structure 110. In some embodiments, the first thickness t1 depends on the fifth thickness t5. For example, if the fifth thickness t5 of the OCZT material 908 increases, the first thickness t1 of the first pattern enhancement material 902 also increases.

[0136] In some embodiments, the first pattern enhancement material 902 includes a material that can be dissolved by the same wet etchant used to remove portions of the tantalum material 904, the CZT material 906, and the OCZT material 908. For example, in some embodiments, the wet etchant used to pattern the first magnetic structure 110 is or includes a mixture of nitric acid and hydrofluoric acid. In such embodiments, the first pattern enhancement material 902 may include, for example, tantalum, silicon nitride, titanium, tungsten, zirconium, nickel, silicon germanium, tin, niobium, vanadium, or indium antimony. Additionally, in some embodiments, the first pattern enhancement material 902 may include a material having an oxygen concentration of no more than 10%. If, in some embodiments, the oxygen concentration of the first pattern enhancement material 902 exceeds 10%, the oxygen in the first pattern enhancement material 902 will react with other elements when exposed to the wet etchant and form oxide precipitates.

[0137] Additionally, in some embodiments, the first pattern enhancement material 902 includes a material having a higher etching rate than the OCZT material 908. In other embodiments, the first pattern enhancement material 902 may have a faster or slower etching rate than one or more of the materials in the first magnetic structure 110. In some embodiments, the first pattern enhancement material 902, the tantalum material 904, the CZT material 906, and the OCZT material 908 may each be formed using a deposition process (e.g., physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PE-CVD), atomic layer deposition (ALD), sputtering, etc.). Depending on the number of layer groups (e.g., 110a, 110b, 110c, etc.) in the first magnetic structure 110, multiple cycles of the deposition process may be repeated for the tantalum material 904, the CZT material 906, and the OCZT material 908.

[0138] like Fig.10 As shown in the cross-sectional view 1000 of FIG. 1 , a first mask layer 1002 is formed over the first magnetic structure 110. In some embodiments, the first mask layer 1002 may include a photoresist material and may be formed using a photolithography and removal (e.g., etching) process. The first mask layer 1002 may be arranged so that an outer portion of the first magnetic structure 110 is not directly under the first mask layer 1002.

[0139] like Fig.11A As shown in cross-sectional view 1100A of FIG. 1 , a first wet etching process is performed to remove an outer portion of the first magnetic structure 110 and an outer portion of the first pattern enhancement material 902. Cross-sectional views 1100A, 1100B, 1100C, 1100D, 1100E, 1100F, and 1100G respectively illustrate the first wet etching process at a first time, a second time, a third time, a fourth time, a fifth time, a sixth time, and a seventh time, wherein the second time is after the first time, the third time is after the second time, and so on.

[0140] The first wet etching process is illustrated by showing a cross-sectional view 1100A immersed in a wet etchant 1102. In some embodiments, for example, the wet etchant 1102 used is a mixture of nitric acid and hydrofluoric acid. During the first time, the topmost OCZT layer 908t is exposed to the wet etchant 1102, and a first region 1104 of the topmost CZT layer 906t is exposed.

[0141] like Fig. 11B As shown in the cross-sectional view 1100B of FIG. 1 , as the first region ( Fig.11A1104) is exposed, and because the CZT material 906 and the tantalum material 904 have a higher etch rate than the OCZT material 908 when exposed to the wet etchant 1102, the wet etchant 1102 quickly removes a portion of the topmost CZT layer 906t and a portion of the topmost tantalum layer 904t. The topmost CZT layer 906t and the topmost tantalum layer 904t are removed much faster than the topmost OCZT layer 908t, causing the OCZT residue 1106 to "free float" in the wet etchant 1102; in other words, the OCZT residue 1106 is not continuous with the topmost OCZT layer 908t, and the OCZT residue 1106 is completely surrounded by the wet etchant 1102. Therefore, the OCZT residue 1106 can be suspended or begin to "sink" (for example, for example, traveling in a direction toward the first pattern enhancement material 902). In some embodiments, the OCZT residue 1106 may exhibit random shapes, or in other words, not common geometric shapes, such as, for example, circles, triangles, rectangles, etc. In some embodiments, the OCZT residue 1106 may be detected as CoO precipitates, for example, during chemical analysis (e.g., EDX analysis). In other embodiments, chemical analysis such as EDX analysis may, for example, detect oxygen, cobalt, zinc, and tantalum when analyzing the OCZT residue 1106.

[0142] like Fig. 11C As shown in the cross-sectional view 1100C of , when the middle OCZT layer 908i is exposed to the wet etchant 1102, the OCZT residue 1106 begins to sink toward the middle OCZT layer 908i. The middle OCZT layer 908i is etched away and the second region 1108 of the middle CZT layer 906i is exposed to the wet etchant 1102.

[0143] In addition, when the middle OCZT layer 908i is exposed to the wet etchant 1102, the OCZT residue 1106 is partially or completely removed by the wet etchant 1102. As the OCZT residue 1106 from the topmost OCZT layer 908t is removed, the OCZT residue 1106 from the middle OCZT layer 908i begins to form. It should be understood that the topmost OCZT layer 908t, the topmost CZT layer 906t, and the topmost tantalum layer 904t continue to be etched (e.g., removed) by the wet etchant 1102, and therefore, the topmost OCZT layer 908t, the topmost CZT layer 906t, and the topmost tantalum layer 904t are removed. Fig. 11C The cross-sectional view 1100C is Fig. 11B The cross-sectional view 1100B is narrow.

[0144] like Fig.11D As shown in the cross-sectional view 1100D, with the second region ( Fig. 11C1108) is exposed, and because the CZT material 906 and the tantalum material 904 have a higher etching rate than the OCZT material 908 when exposed to the wet etchant 1102, the wet etchant 1102 quickly removes portions of the middle CZT layer 906i and portions of the middle tantalum layer 904i. More OCZT residue 1106 from the middle OCZT layer 908i may be left "free floating" in the wet etchant 1102, and other previously formed OCZT residue 1106 from the topmost OCZT layer 908t may be partially or completely removed.

[0145] like Fig.11E As shown in the cross-sectional view 1100E of FIG. 1 , the bottommost OCZT layer 908b, the bottommost CZT layer 906b, and the bottommost tantalum layer 904b are exposed to the wet etchant 1102, and more OCZT residues 1106 may be generated from the bottommost CZT layer 906b. When the first pattern enhancement material 902 is exposed to the wet etchant 1102, some of the OCZT residues 1106 may sink and contact the first pattern enhancement material 902. The OCZT residues 1106 from the topmost OCZT layer 908t and the middle OCZT layer 908i may be almost or completely removed.

[0146] like Fig.11F As shown in the cross-sectional view 1100F of FIG. 1 , as the first magnetic structure 110 continues to be exposed and etched by the wet etchant 1102, portions of the first pattern enhancement material 902 begin to be removed by the wet etchant 1102. The wet etchant 1102 also continues to remove the OCZT residue 1106 before exposing the first etch stop layer 106. Therefore, the first pattern enhancement material 902 gives the wet etching process more time to remove the OCZT residue 1106 before exposing the first etch stop layer 106. If the first etch stop layer 106 is exposed before the OCZT residue 1106 is removed, the OCZT residue 1106 will contact and adhere to the first etch stop layer 106, thereby negatively affecting device performance. Increasing the thickness of the first pattern enhancement material 902 and / or selecting a material for the first pattern enhancement material 902 that has a slower etch rate may increase the time to remove the OCZT residue 1106 during the first wet etching process.

[0147] Fig.11GThe cross-sectional view 1100G of FIG. 1 may show the first magnetic structure 110 after the first wet etching process is completed. The first magnetic structure 110 includes a plurality of tantalum layers 162, CZT layers 164, and OCZT layers 166. The first pattern enhancement layer 108 may be disposed between the first etch stop layer 106 and the lowermost tantalum layer 162. Depending on the etching rate and / or the etching time of the first wet etching process, the first pattern enhancement layer 108 may be wider, narrower, or approximately equal to the lowermost tantalum layer 162. In some embodiments, the first magnetic structure 110 may have a curved outermost sidewall.

[0148] In some embodiments, since the first wet etching process includes the wet etchant 1102, the first magnetic structure 110 and the first pattern enhancement layer 108 are removed laterally and vertically, and at least the topmost layer 110t of the first magnetic structure 110 may be narrower than the first mask layer 1002. After the first wet etching process, in some embodiments, the first magnetic structure 110 and the first pattern enhancement layer 108 may be completely and directly below the first mask layer 1002. In addition, the first etch stop layer 106 may resist removal by the wet etchant 1102 (e.g., nitric acid and hydrofluoric acid), thereby protecting the underlying layers of the inductor structure (e.g., Fig. 9 The first passivation layer 102, Fig. 9 After the first wet etching process, the wet etchant 1102 and the first mask layer 1002 are removed. The first pattern enhancement layer 108 significantly reduces the OCZT residue on the first etch stop layer 106 ( Fig.11F Therefore, if a chemical analysis (eg, EDX analysis) is performed on the first etch stop layer 106 after the first wet etching process, in some embodiments, no OCZT residue may be detected ( Fig.11F 1106), such as CoO precipitates.

[0149] like Fig.12 As shown in the cross-sectional view 1200 of , a second etching process may be performed to remove an outer portion of the first etch stop layer 106. A second mask layer (not shown) may be formed over the first magnetic structure 110 and / or the first etch stop layer 106, and a second etching process may be performed based on the second mask layer. The second etching process may be a dry etching process in a substantially vertical direction.

[0150] In other embodiments (not shown), the second etching process may be omitted, so that the method is Fig.11G Continue to Fig.13 , thus skipping Fig.12 .

[0151] like Fig.13As shown in the cross-sectional view 1300 of FIG. 1 , a first conductive wire 114 and a second conductive wire 116 may be formed on the first magnetic structure 110. In some embodiments, the first conductive wire 114 and the second conductive wire 116 are spaced apart from each other in the lateral direction. The second barrier layer 112 and the seed layer 1202 may separate each of the first conductive wire 114 and the second conductive wire 116 from the first magnetic structure 110. In some embodiments, the second barrier layer 112 may, for example, include a dielectric material such as silicon dioxide, silicon nitride, a low-k dielectric, or some other suitable dielectric material. The second barrier layer 112 may, for example, be deposited or grown by CVD, PVD, ALD, or some other deposition or growth process. In some embodiments, a seed layer 1202 may be formed on the second barrier layer 112. The seed layer 1202 may include copper, aluminum, gold, silver, alloys of the foregoing materials, or other suitable materials. The seed layer 1202 may be deposited or grown, for example, by CVD, PVD, sputtering, electrochemical plating, electroless plating, or some other deposition or growth process. Then, the first conductive wire 114 and the second conductive wire 116 may be formed on the seed layer 1202 and the first conductive wire 114 and the second conductive wire 116 may directly contact the seed layer 1202. The first conductive wire 114 and the second conductive wire 116 may each include copper, aluminum, gold, silver, alloys of the foregoing materials, or any other suitable conductive material. The first conductive wire 114 and the second conductive wire 116 may be deposited or grown, for example, by CVD, PVD, sputtering, electrochemical plating (ECP), electroless plating, or some other deposition or growth process. In some embodiments, for example, the second barrier layer 112, the seed layer 1202, and / or the first and second conductive wires 114, 116 may be grown or deposited in a patterned photoresist layer, and the patterned photoresist layer may be subsequently removed after such deposition or growth process.

[0152] like Fig.14 As shown in the cross-sectional view 1400 of FIG. 1 , a dielectric structure 118 may be deposited over the first magnetic structure 110 and over the first conductive wire 114 and the second conductive wire 116. The dielectric structure 118 is configured to electrically isolate the first conductive wire 114 and the second conductive wire 116 from each other and may include, for example, a polyimide compound, a polybenzoxazole compound, or any other suitable dielectric material.

[0153] In some embodiments, the dielectric structure 118 may be deposited and / or grown by CVD, PVD, ALD, or another suitable deposition process. In some embodiments, the dielectric structure 118 may be formed by, for example, a curing process or a patterning and removal (e.g., etching) process. In some embodiments, the dielectric structure 118 may have a dome-shaped upper surface. In other embodiments, the dielectric structure may have a substantially flat upper surface by a patterning process (e.g., etching process) and / or a planarization process (e.g., chemical mechanical planarization process). In yet other embodiments, the dielectric structure may have a central portion that is recessed below the topmost portion. The central portion is located between the first conductive wiring 114 and the second conductive wiring 116.

[0154] like Fig.15 As shown in the cross-sectional view 1500 of , a first isolation layer 120 may be formed on the dielectric structure 118. The first isolation layer 120 may, for example, include nitride, silicon nitride, or another suitable dielectric material, and the first isolation layer 120 may be deposited and / or grown by CVD, PVD, ALD, or another suitable deposition process.

[0155] like Fig.16 As shown in the cross-sectional view 1600 of FIG. 1 , a third barrier layer 122 may be formed overlying the first isolation layer 120 and laterally surrounding the first magnetic structure 110 and the first pattern enhancement layer 108. The third barrier layer 122 may include, for example, silicon nitride, silicon carbide, etc. In some embodiments, the third barrier layer 122 may be deposited and / or grown by CVD, PVD, ALD, or another suitable deposition process.

[0156] like Fig.17 As shown in the cross-sectional view 1700 of , a second etch stop layer 124 may be formed over the third barrier layer 122, the first etch stop layer 106, and the first barrier layer 104. In some embodiments, the second etch stop layer 124 may include the same material as the first etch stop layer 106 and / or be formed using the same process as the first etch stop layer 106.

[0157] like Fig.18 As shown in the cross-sectional view 1800 of FIG. 1 , in some embodiments, a second pattern enhancement material 1802 may be conformally formed on the second etch stop layer 124. The second pattern enhancement material 1802 may include the same or different material as the first pattern enhancement layer 108. In other embodiments, it should be understood that the second pattern enhancement material 1802 may be omitted and the method may be performed from Fig.17 Continue to Fig.19 , thus skipping Fig.18 .

[0158] like Fig.19As shown in the cross-sectional view 1900 of , in some embodiments, a second magnetic structure 126 may be formed over the second etch stop layer 124 and, in some embodiments, over the second pattern enhancement material 1802. In some embodiments, the second magnetic structure 126 includes a different structure than the first magnetic structure 110. For example, in some embodiments, the second magnetic structure 126 may not include oxycobalt zinc tantalum. In such an embodiment, the second pattern enhancement material 1802 may be omitted. In other embodiments, the second magnetic structure 126 may include the same structure as the first magnetic structure 110. In such other embodiments, the second pattern enhancement material 1802 may be present to remove residues formed during patterning of the second magnetic structure 126. In some embodiments, the second pattern enhancement material 1802 and the second magnetic structure 126 may be removed by the same etchant.

[0159] like Fig. 20 As shown in the cross-sectional view 2000 of FIG. 1 , in some embodiments, the second magnetic structure 126 may undergo a third wet etching process to remove an outer portion of the second magnetic structure 126. In some embodiments, during the third wet etching process, the second pattern enhancement material ( Fig.19 1802), thereby forming a second pattern enhancement layer 508 between the second etch stop layer 124 and the second magnetic structure 126. In such an embodiment, the second pattern enhancement layer 508 can enable the third wet etching process to have more space and more time to remove any residues generated by the second magnetic structure 126 during the third wet etching process. In other embodiments, the residue is not a side effect of the third wet etching process, and therefore, the second pattern enhancement layer 508 can be omitted. In addition, in some embodiments, the third wet etching process can be followed by a fourth etching process to remove the outer portion of the second etch stop layer 124.

[0160] It should be understood that preventing the formation of residues on the second etch stop layer 124 by the second pattern enhancement layer 508 during the third wet etching process may involve FIG. 11A to FIG. 11G In the embodiment of the present invention, the first pattern enhancement layer 108 is used to prevent the OCZT residue on the first etch stop layer 106 from being formed during the first wet etching process. Fig. 11B A mechanism similar to the mechanism depicted in 1106).

[0161] However, due to the first pattern reinforcement layer 108 and / or the second pattern reinforcement layer 508, the residue between the layers of the inductor structure (eg, Fig.11F The OCZT residue 1106 is formed so that the first magnetic structure 110 and the second magnetic structure 126 can reliably surround the first conductive wiring 114 and the second conductive wiring 116.

[0162] Fig.21 A flow chart illustrating some embodiments of a method 2100 of forming an inductor structure having a first pattern enhancement layer disposed between a first magnetic structure and a first etch stop layer.

[0163] Although method 2100 is shown and described as a series of actions or events below, it should be understood that the order in which these actions or events are shown should not be interpreted as having a limiting meaning. For example, some actions can occur in different orders and / or can occur simultaneously with other actions or events other than the actions or events shown and / or described herein. In addition, all the actions shown may not be needed when implementing one or more aspects or embodiments described herein. In addition, one or more actions in the actions depicted herein can be implemented in one or more separate actions and / or stages.

[0164] At act 2102, a first pattern enhancement layer is formed over the first etch stop layer.

[0165] At act 2104, a first magnetic structure is formed over the first pattern enhancement layer. Fig. 9 Cross-sectional view 900 of some embodiments corresponding to acts 2102 and 2104 is shown.

[0166] At act 2106 , a mask layer is formed over the first magnetic structure. Fig.10 Cross-sectional view 1000 of some embodiments corresponding to act 2106 is shown.

[0167] At action 2108, a first etching process is performed to remove a peripheral portion of the first magnetic structure and a peripheral portion of the first pattern enhancement layer. Fig.11A and Fig. 11B Cross-sectional view 1100A and cross-sectional view 1100B of some embodiments corresponding to action 2108 are respectively shown.

[0168] At act 2110, a second etch process is performed to remove an outer portion of the first etch stop layer. Fig.12 Cross-sectional view 1200 of some embodiments corresponding to act 2110 is shown.

[0169] At act 2112, a first conductive wire and a second conductive wire are formed over the first magnetic structure. Fig.13 Cross-sectional view 1300 of some embodiments corresponding to act 2112 is shown.

[0170] At act 2114, a dielectric structure is deposited over the first conductive wire and the second conductive wire, wherein the dielectric structure separates the first conductive wire from the second conductive wire and covers the first conductive wire and the second conductive wire. Fig.14Cross-sectional view 1400 of some embodiments corresponding to act 2114 is shown.

[0171] At act 2116, a second etch stop layer is formed over the dielectric structure. Fig.17 Cross-sectional view 1700 of some embodiments corresponding to act 2116 is shown.

[0172] At act 2118, a second magnetic structure is formed over the second etch stop layer. Fig.19 Cross-sectional view 1900 of some embodiments corresponding to act 2118 is shown.

[0173] Therefore, the present invention is directed to a new method of manufacturing an inductor structure having a first pattern enhancement layer disposed between a first magnetic structure and a first etch stop layer to mitigate the presence of residues when patterning the first magnetic structure.

[0174] Therefore, in some embodiments, the present invention relates to an inductor structure, which includes: an etch stop layer arranged on an interconnect structure, which is overlying a substrate; a magnetic structure, including a plurality of stacked layers arranged on the etch stop layer, the magnetic structure including a bottom layer wider than a top layer; a first conductive wire and a second conductive wire extending in parallel on the magnetic structure, wherein the magnetic structure is configured to modify the magnetic field generated by the first conductive wire and the second conductive wire; and a pattern enhancement layer arranged between the bottom layer of the magnetic structure and the etch stop layer, wherein the pattern enhancement layer has a first thickness, and wherein the bottom layer of the magnetic structure has a second thickness less than the first thickness.

[0175] In some embodiments, the bottom layer of the magnetic structure comprises tantalum, and the top layer of the magnetic structure comprises tantalum-cobalt-zinc-tantalum. In some embodiments, the pattern enhancement layer has a bottom surface, the bottom surface of the pattern enhancement layer directly contacts the etch stop layer and has a first width, wherein the bottom layer of the magnetic structure has a bottom surface, the bottom surface of the bottom layer of the magnetic structure directly contacts the pattern enhancement layer and has a second width greater than the first width. In some embodiments, the pattern enhancement layer has a bottom surface, the bottom surface of the pattern enhancement layer directly contacts the etch stop layer and has a first width, wherein the bottom layer of the magnetic structure has a bottom surface, the bottom surface of the bottom layer of the magnetic structure directly contacts the pattern enhancement layer and has a second width less than the first width. In some embodiments, the pattern enhancement layer has a composition comprising less than 10% oxygen. In some embodiments, the pattern enhancement layer comprises one or more of the following: tantalum, silicon nitride, titanium, tungsten, nickel, zirconium, silicon germanium, tin, niobium, vanadium, or indium antimony. In some embodiments, the top layer of the magnetic structure comprises tantalum-cobalt-zinc-tantalum, and wherein the pattern enhancement layer has a faster etching rate than the top layer of the magnetic structure. In some embodiments, the interconnect structure includes a plurality of interconnect layers disposed within a dielectric structure and bonding pads disposed on the plurality of interconnect layers; and the etch stop layer is located above the bonding pads in a vertical direction.

[0176] In other embodiments, the present invention relates to an inductor structure, which includes: an interconnect structure disposed on a semiconductor substrate; a first etch stop layer arranged on the interconnect structure; a first magnetic structure disposed on the first etch stop layer, the first magnetic structure including a cobalt zinc tantalum (CZT) layer located between a bottom tantalum layer and a top oxygen cobalt zinc tantalum layer; one or more conductive wires disposed on the first magnetic structure and defining an inductor; and a pattern enhancement layer disposed between the bottom tantalum layer and the first etch stop layer.

[0177] In some embodiments, the pattern enhancement layer has a top surface having a first width, wherein the lowermost tantalum layer has a bottom surface having a second width, the second width being less than the first width, and wherein the top surface of the pattern enhancement layer directly contacts the bottom surface of the lowermost tantalum layer. In some embodiments, the pattern enhancement layer has a top surface having a first width, wherein the lowermost tantalum layer has a bottom surface having a second width, the second width being greater than the first width, and wherein the top surface of the pattern enhancement layer directly contacts the bottom surface of the lowermost tantalum layer. In some embodiments, the pattern enhancement layer has a first etch rate when exposed to a wet etchant, wherein the uppermost tantalum oxide cobalt zinc layer has a second etch rate when exposed to the wet etchant, and wherein the first etch rate is greater than the second etch rate. In some embodiments, the inductor structure further comprises: a first conductive wire disposed on the first magnetic structure; a second conductive wire disposed on the first magnetic structure and laterally spaced apart from the first conductive wire; a dielectric layer disposed on and between the first conductive wire and the second conductive wire; a second etch stop layer disposed on the dielectric layer; and a second magnetic structure disposed on the second etch stop layer. In some embodiments, the inductor structure further comprises: a second pattern enhancement layer disposed between the second etch stop layer and the second magnetic structure. In some embodiments, the second pattern enhancement layer comprises a topmost portion directly overlying the first conductive wire and the second conductive wire, wherein the second pattern enhancement layer comprises a center portion disposed between the first conductive wire and the second conductive wire, and wherein the center portion is recessed below the topmost portion of the second pattern enhancement layer.

[0178] In some other embodiments, the present invention relates to a method for forming an inductor structure, the method comprising: forming a first pattern enhancement layer on a first etch stop layer; forming a magnetic structure on the first pattern enhancement layer, wherein the magnetic structure comprises an oxycobalt zinc tantalum (OCZT) material layer, a tantalum material layer, and a cobalt zinc tantalum (CZT) material layer, wherein the first pattern enhancement layer directly contacts one of the tantalum material layers; and performing a first etching process to remove a peripheral portion of the magnetic structure and a peripheral portion of the first pattern enhancement layer, wherein the magnetic structure and the first pattern enhancement layer are etched by the same etchant.

[0179] In some embodiments, during a first time of the first etching process, the first pattern enhancement layer completely covers the first etch stop layer, and cobalt oxide precipitates are surrounded by a wet etchant of the first etching process; wherein during a second time of the first etching process, the wet etchant removes the cobalt oxide precipitates; and wherein during a third time of the first etching process, the wet etchant removes the first pattern enhancement layer from portions of the first etch stop layer. In some embodiments, the same etchant of the first etching process is a wet etchant, and wherein the wet etchant comprises a mixture of nitric acid and hydrofluoric acid. In some embodiments, the method of forming an inductor structure further comprises: forming a first conductive wire and a second conductive wire over the magnetic structure, wherein the first conductive wire and the second conductive wire are laterally spaced apart from each other; depositing a dielectric material over the first conductive wire and the second conductive wire, wherein the dielectric material completely covers a top surface of the first conductive wire and a top surface of the second conductive wire; forming a second etch stop layer over the dielectric material; and forming an additional magnetic structure over the second etch stop layer. In some embodiments, after forming the second etch stop layer and before forming the additional magnetic structure, the method of forming an inductor structure further includes: forming a second pattern enhancement layer over the second etch stop layer.

[0180] The features of several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the present invention. Those skilled in the art will appreciate that they can easily use the present invention as a basis for designing or modifying other processes and structures to implement the same purposes and / or achieve the same advantages as the embodiments described herein. Those skilled in the art will also recognize that these equivalent constructions do not depart from the spirit and scope of the present invention, and that they can make various changes, substitutions and modifications to the present invention without departing from the spirit and scope of the present invention.

Claims

1. An inductor structure, comprising: an etch stop layer disposed on the interconnect structure overlying the substrate; a magnetic structure comprising a plurality of stacked layers disposed above the etch stop layer, the magnetic structure comprising a bottommost layer that is wider than a topmost layer; a first conductive wire and a second conductive wire extending in parallel over the magnetic structure, wherein the magnetic structure is configured to modify a magnetic field generated by the first conductive wire and the second conductive wire; as well as A pattern enhancement layer is arranged between the bottom layer of the magnetic structure and the etch stop layer, wherein The pattern enhancement layer has a first thickness, The bottom layer of the magnetic structure has a second thickness that is less than the first thickness, The pattern enhancement layer includes one or more of: tantalum, silicon nitride, titanium, tungsten, nickel, zirconium, silicon germanium, tin, niobium, vanadium, or indium antimony, The topmost layer of the magnetic structure comprises tantalum-cobalt-oxygen, and The pattern enhancement layer has a faster etching rate than the topmost layer of the magnetic structure.

2. The inductor structure of claim 1, wherein the bottom-most layer of the magnetic structure comprises tantalum and the top-most layer of the magnetic structure comprises tantalum oxide cobalt zinc.

3. The inductor structure of claim 1 , wherein the pattern enhancement layer has a bottom surface, the bottom surface of the pattern enhancement layer directly contacts the etch stop layer and has a first width, wherein the bottom layer of the magnetic structure has a bottom surface, the bottom surface of the bottom layer of the magnetic structure directly contacts the pattern enhancement layer and has a second width greater than the first width.

4. The inductor structure of claim 1 , wherein the pattern enhancement layer has a bottom surface, the bottom surface of the pattern enhancement layer directly contacts the etch stop layer and has a first width, wherein the bottom layer of the magnetic structure has a bottom surface, the bottom surface of the bottom layer of the magnetic structure directly contacts the pattern enhancement layer and has a second width smaller than the first width.

5. The inductor structure of claim 1, wherein the pattern enhancement layer has a composition including less than 10% oxygen.

6. The inductor structure according to claim 1, wherein the interconnect structure comprises a plurality of interconnect layers disposed in the dielectric structure and bonding pads disposed on the plurality of interconnect layers; and The etch stop layer is located above the bonding pad in a vertical direction.

7. An inductor structure comprising: An interconnect structure is disposed on a semiconductor substrate; A first etch stop layer, arranged on the interconnect structure; a first magnetic structure disposed on the first etch stop layer, the first magnetic structure comprising a cobalt zinc tantalum layer between a bottommost tantalum layer and a topmost oxygen cobalt zinc tantalum layer; one or more conductive traces disposed on the first magnetic structure and defining an inductor; as well as A pattern enhancement layer is arranged between the lowermost tantalum layer and the first etch stop layer, wherein The pattern enhancement layer has a first thickness, the lowermost tantalum layer has a second thickness less than the first thickness, The pattern enhancement layer includes one or more of: tantalum, silicon nitride, titanium, tungsten, nickel, zirconium, silicon germanium, tin, niobium, vanadium, or indium antimony, and The pattern enhancement layer has a first etch rate when exposed to a wet etchant, the topmost oxygen-cobalt-zinc-tantalum layer has a second etch rate when exposed to the wet etchant, and the first etch rate is greater than the second etch rate.

8. The inductor structure of claim 7, wherein the pattern enhancement layer has a top surface having a first width, wherein the lowermost tantalum layer has a bottom surface having a second width, the second width being smaller than the first width, and wherein the top surface of the pattern enhancement layer directly contacts the bottom surface of the lowermost tantalum layer.

9. The inductor structure of claim 7, wherein the pattern enhancement layer has a top surface having a first width, wherein the lowermost tantalum layer has a bottom surface having a second width, the second width being greater than the first width, and wherein the top surface of the pattern enhancement layer directly contacts the bottom surface of the lowermost tantalum layer.

10. The inductor structure of claim 7, further comprising: a first conductive wiring, arranged on the first magnetic structure; a second conductive wire disposed on the first magnetic structure and laterally spaced apart from the first conductive wire; a dielectric layer disposed on the first conductive wiring and the second conductive wiring and between the first conductive wiring and the second conductive wiring; a second etch stop layer disposed on the dielectric layer; as well as The second magnetic structure is arranged on the second etch stop layer.

11. The inductor structure of claim 10, further comprising: The second pattern enhancement layer is arranged between the second etch stop layer and the second magnetic structure.

12. An inductor structure according to claim 11, wherein the second pattern reinforcement layer includes a topmost portion directly overlying the first conductive wiring and the second conductive wiring, wherein the second pattern reinforcement layer includes a center portion arranged between the first conductive wiring and the second conductive wiring, and wherein the center portion is recessed below the topmost portion of the second pattern reinforcement layer.

13. A method of forming an inductor structure, comprising: forming a first pattern enhancement layer over the first etch stop layer; forming a magnetic structure over the first pattern enhancement layer, wherein the magnetic structure comprises an oxygen-cobalt-zinc-tantalum material layer, a tantalum material layer, and a cobalt-zinc-tantalum material layer, wherein the first pattern enhancement layer directly contacts one of the tantalum material layers; as well as removing the peripheral portion of the magnetic structure and the peripheral portion of the first pattern enhancement layer, wherein the magnetic structure and the first pattern enhancement layer are etched by the same etchant in a first etching process, wherein The first pattern enhancement layer has a first thickness, The tantalum material layer has a second thickness less than the first thickness, The first pattern enhancement layer includes one or more of the following: tantalum, silicon nitride, titanium, tungsten, nickel, zirconium, silicon germanium, tin, niobium, vanadium or indium antimony, The topmost layer of the magnetic structure comprises the tantalum-cobalt-oxygen material layer, and The first pattern enhancement layer has an etching rate faster than the topmost layer of the magnetic structure.

14. A method for forming an inductor structure according to claim 13, wherein during a first time of the first etching process, the first pattern enhancement layer completely covers the first etch stop layer, and cobalt oxide precipitates are surrounded by a wet etchant of the first etching process; wherein during a second time of the first etching process, the wet etchant removes the cobalt oxide precipitates; and wherein during a third time of the first etching process, the wet etchant removes the first pattern enhancement layer from some portions of the first etch stop layer.

15. The method of forming an inductor structure of claim 13, wherein the same etchant of the first etching process is a wet etchant, and wherein the wet etchant comprises a mixture of nitric acid and hydrofluoric acid.

16. The method of forming an inductor structure according to claim 13, further comprising: forming a first conductive wire and a second conductive wire over the magnetic structure, wherein the first conductive wire and the second conductive wire are laterally spaced apart from each other; depositing a dielectric material over the first conductive wire and the second conductive wire, wherein the dielectric material completely covers a top surface of the first conductive wire and a top surface of the second conductive wire; forming a second etch stop layer over the dielectric material; as well as An additional magnetic structure is formed over the second etch stop layer.

17. The method for forming an inductor structure according to claim 16, wherein after forming the second etch stop layer and before forming the additional magnetic structure, the method for forming an inductor structure further comprises: A second pattern enhancement layer is formed over the second etch stop layer.

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