TWI802218B - Capacitor structure and manufacturing method thereof - Google Patents

Abstract

A capacitor structure including a substrate and a capacitor is provided. The capacitor includes a first electrode, a second electrode, and a first dielectric layer. The first electrode is disposed on the substrate. The first electrode has openings penetrating through the first electrode, and a shape of the first electrode includes a lattice shape. The second electrode is disposed on the first electrode and fills the openings. The first dielectric layer is disposed between the first electrode and the second electrode.

Description

Capacitor structure and manufacturing method thereof

The present invention relates to a semiconductor structure and its manufacturing method, and in particular to a capacitor structure and its manufacturing method.

A capacitor is a passive component widely used in electronic products. However, as the integration level of semiconductor devices continues to increase, the size of capacitors also shrinks. Therefore, how to improve the capacitance per unit area is the goal of continuous efforts in the case of shrinking the size of the capacitor.

The invention provides a capacitor structure and a manufacturing method thereof, which can increase the capacitance per unit area.

The invention provides a capacitor structure, including a substrate and a capacitor. The capacitor includes a first electrode, a second electrode and a first dielectric layer. The first electrode is disposed on the base. The first electrode has a plurality of openings passing through the first electrode, and the shape of the first electrode includes a lattice shape. The second electrode is disposed on the first electrode and fills in the openings. The first dielectric layer is disposed between the first electrode and the second electrode.

According to an embodiment of the present invention, in the above capacitor structure, the second electrode may be a single-layer structure.

According to an embodiment of the present invention, in the above capacitor structure, the second electrode may be a multi-layer structure.

According to an embodiment of the present invention, the above capacitor structure may further include pads. The pad is disposed between the first electrode and the base. The first electrode can be electrically connected to the pad.

According to an embodiment of the present invention, the above capacitor structure may further include a second dielectric layer. The second dielectric layer is disposed on the substrate. Part of the capacitor may be located in the second dielectric layer.

The invention provides a method for manufacturing a capacitor structure, which includes the following steps. Provide the base. A capacitor is formed on the substrate. The capacitor includes a first electrode, a second electrode and a first dielectric layer. The first electrode is disposed on the base. The first electrode has a plurality of openings passing through the first electrode, and the shape of the first electrode includes a lattice shape. The second electrode is disposed on the first electrode and fills in the openings. The first dielectric layer is disposed between the first electrode and the second electrode.

According to an embodiment of the present invention, in the method for manufacturing the above capacitor structure, the method for forming the first electrode may include the following steps. A second dielectric layer is formed on the substrate. A lattice opening is formed in the second dielectric layer. The lattice openings penetrate the second dielectric layer, so that the second dielectric layer has a plurality of dielectric columns. A grid of openings may surround a plurality of dielectric posts. An electrode material layer filling the lattice openings is formed on the second dielectric layer. A layer of electrode material may cover a plurality of dielectric pillars. Part of the electrode material layer is removed to expose a plurality of dielectric pillars and form a first electrode.

According to an embodiment of the present invention, the manufacturing method of the above capacitor structure may further include the following steps. A plurality of dielectric pillars are removed to form a plurality of openings through the first electrode.

According to an embodiment of the present invention, in the method for manufacturing the above capacitor structure, the method for forming the first dielectric layer and the second electrode may include the following steps. A layer of dielectric material is conformally formed over the first electrode and within the plurality of openings. A layer of electrode material is formed on the layer of dielectric material. A layer of electrode material fills the plurality of openings. The electrode material layer and the dielectric material layer are patterned to form the second electrode and the first dielectric layer.

According to an embodiment of the present invention, the manufacturing method of the above capacitor structure may further include the following steps. Before forming the first electrode, a contact pad is formed on the substrate. The first electrode can be electrically connected to the pad.

Based on the above, in the capacitor structure and manufacturing method proposed by the present invention, since the shape of the first electrode includes a grid shape, the first electrode can have a larger surface area, thereby increasing the capacitance per unit area.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

1A to 1E are top views of the fabrication process of electrodes according to some embodiments of the present invention. 2A-2H are cross-sectional views of the fabrication process of capacitor structures according to some embodiments of the present invention. 2A to 2H are sectional views of the manufacturing process along the line I-I' in FIG. 1A . 2A to 2E are cross-sectional views of FIGS. 1A to 1E , respectively. In the top view of this embodiment, some components in the cross-sectional view are omitted to clearly illustrate the positional relationship between the various components in the top view.

Referring to FIG. 1A and FIG. 2A , a substrate 100 is provided. The substrate 100 can be a semiconductor substrate, such as a silicon substrate. In addition, although not shown in FIG. 2A, there may be required components such as doped regions and/or isolation structures in the substrate 100, and there may be semiconductor elements (such as active elements such as transistors) on the substrate 100. , dielectric layer and/or interconnection structure, etc., and the description thereof is omitted here.

Next, pads 102 may be formed on the substrate 100 . The material of the pad 102 is, for example, a conductive material such as tungsten (W) or aluminum (Al). The pads 102 can be formed by deposition process, lithography process and etching. In some embodiments, a silicon nitride protective layer (not shown) may be further formed on the pad 102 .

Then, a dielectric layer 104 may be formed on the substrate 100 . The dielectric layer 104 can cover the pads 102 . The material of the dielectric layer 104 is, for example, a dielectric material such as silicon oxide. The forming method of the dielectric layer 104 is, for example, chemical vapor deposition.

Referring to FIG. 1B and FIG. 2B , lattice openings OP1 may be formed in the dielectric layer 104 . For example, the top view shape of the lattice opening OP1 may be lattice ( FIG. 1B ). The lattice opening OP1 penetrates the dielectric layer 104 such that the dielectric layer 104 has a plurality of dielectric columns 104 a. The top-view shape of the dielectric pillar 104a may include a circle, an ellipse or a polygon. The lattice opening OP1 may surround a plurality of dielectric pillars 104a. In some embodiments, the lattice opening OP1 can expose part of the pads 102 . A method for forming the lattice opening OP1 is, for example, patterning the dielectric layer 104 . In some embodiments, the dielectric layer 104 can be patterned by a lithography process and an etching process (eg, a dry etching process). In some other embodiments, the dielectric layer 104 may be patterned by performing a dry etching process on the dielectric layer 104 by using the patterned hard mask layer as a mask. In addition, in the dry etching process for forming the lattice opening OP1, the pad 102 can be used as an etching stop layer. In some embodiments, if there is a silicon nitride protective layer (not shown) on the contact pad 102, the silicon nitride protective layer can be patterned so that the lattice opening OP1 penetrates the silicon nitride protective layer. , and part of the pad 102 is exposed.

Referring to FIG. 1C and FIG. 2C , an electrode material layer 106 filling the lattice opening OP1 can be formed on the dielectric layer 104 . A layer of electrode material 106 may cover the plurality of dielectric pillars 104a. The material of the electrode material layer 106 is, for example, a conductive material such as titanium nitride (TiN) or tungsten. The method for forming the electrode material layer 106 is, for example, chemical vapor deposition.

Referring to FIG. 1D and FIG. 2D , part of the electrode material layer 106 can be removed to expose a plurality of dielectric pillars 104 a and form electrodes 106 a. The electrode 106 a is electrically connected to the pad 102 . The part of the electrode 106 a can be located in the lattice opening OP1 , that is, the part of the electrode 106 a can be located in the dielectric layer 104 . Since part of the electrode 106a can be located in the lattice opening OP1, the shape of the electrode 106a can include a lattice shape. For example, the top view shape of the electrode 106a may include a lattice shape ( FIG. 1D ). In some embodiments, part of the electrodes 106 a may be located on the top surface TS of the dielectric layer 104 . In addition, the electrode 106a located in the dielectric layer 104 and the electrode 106a located on the top surface TS of the dielectric layer 104 can be integrally formed and can be connected to each other. A method for removing part of the electrode material layer 106 is, for example, patterning the electrode material layer 106 through a lithography process and an etching process (eg, a dry etching process).

Referring to FIG. 1E and FIG. 2E , a plurality of dielectric pillars 104 a can be removed to form a plurality of openings OP2 penetrating through the electrode 106 a. In some embodiments, the opening OP2 can expose a portion of the pad 102 . The removal method of the dielectric pillar 104a is, for example, a wet etching method.

Referring to FIG. 2F , the dielectric material layer 108 may be conformally formed on the electrode 106 a and in the plurality of openings OP2 . The dielectric material layer 108 can be a single-layer structure or a multi-layer structure. The material of the dielectric material layer 108 can be a high-k material, such as zirconia (ZrO ₂ ), aluminum oxide (Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), or a combination thereof.

Referring to FIG. 2G , an electrode material layer 110 is formed on the dielectric material layer 108 . The electrode material layer 110 fills the plurality of openings OP2. The electrode material layer 110 may be a single-layer structure or a multi-layer structure. In this embodiment, the electrode material layer 110 is an example of a multi-layer structure. For example, the electrode material layer 110 may include the electrode material layer 112 , the electrode material layer 114 and the electrode material layer 116 , but the invention is not limited thereto. The electrode material layer 112 may be conformally formed on the dielectric material layer 108 . The material of the electrode material layer 112 is, for example, a conductive material such as titanium nitride. The method for forming the electrode material layer 112 is, for example, chemical vapor deposition. The electrode material layer 114 may be formed on the electrode material layer 112 and may fill the plurality of openings OP2. The material of the electrode material layer 114 is, for example, conductive material such as doped polysilicon. The method for forming the electrode material layer 114 is, for example, chemical vapor deposition. An electrode material layer 116 may be formed on the electrode material layer 114 . The material of the electrode material layer 116 is, for example, a conductive material such as tungsten. The formation method of the electrode material layer 116 is, for example, chemical vapor deposition or physical vapor deposition.

Referring to FIG. 2H, the electrode material layer 110 and the dielectric material layer 108 are patterned to form the electrode 110a and the dielectric layer 108a. For example, the electrode material layer 110 and the dielectric material layer 108 can be patterned by a lithography process and an etching process (eg, a dry etching process). In the patterning process of the electrode material layer 110 , the electrode material layer 116 , the electrode material layer 114 and the electrode material layer 112 can be patterned respectively to form the electrode 116 a , the electrode 114 a and the electrode 112 a . In this embodiment, the electrode 110a may be a multilayer structure. For example, the electrode 110a may include an electrode 112a, an electrode 114a, and an electrode 116a sequentially disposed on the dielectric layer 108a, but the invention is not limited thereto. In other embodiments, the electrode 110a may be a single-layer structure.

In some embodiments, the electrode 106a can be further patterned according to requirements, so that the electrode 106a has a desired pattern. Through the above method, the capacitor 118 can be formed on the substrate 100 . The capacitor 118 includes an electrode 106a, an electrode 110a and a dielectric layer 108a.

Hereinafter, the capacitor structure 10 of this embodiment will be described with reference to FIG. 2H . In addition, although the method for forming the capacitor structure 10 is described by taking the above method as an example, the present invention is not limited thereto.

Referring to FIG. 2H , the capacitor structure 10 includes a substrate 100 and a capacitor 118 . The capacitor 118 includes an electrode 106a, an electrode 110a and a dielectric layer 108a. The electrode 106a is disposed on the substrate 100 . The electrode 106a has a plurality of openings OP2 penetrating through the electrode 106a, and the shape of the electrode 106a includes a lattice shape. For example, the top-view shape of the electrode 106a may include a lattice shape (FIG. 1E). Since the shape of the electrode 106a includes a grid shape, the electrode 106a can have a larger surface area, thereby increasing the capacitance per unit area. The electrode 110a is disposed on the electrode 106a and fills the plurality of openings OP2. The electrode 110a may have a single-layer structure or a multi-layer structure. The dielectric layer 108a is disposed between the electrode 106a and the electrode 110a. The dielectric layer 108a can be a single-layer structure or a multi-layer structure.

The capacitor structure 10 may further include pads 102 . The pad 102 is disposed between the electrode 106 a and the substrate 100 . The contact pad 102 can be used as a landing pad for the electrode 106a. The electrode 106a can be electrically connected to the pad 102, so the pad 102 can be regarded as an extension of the electrode 106a. That is, the surface area of the electrode 106a can be further increased by the contact pad 102, so the capacitance per unit area can be further increased.

The capacitor structure 10 may further include a dielectric layer 104 . A dielectric layer 104 is disposed on the substrate 100 . Portions of capacitors 118 may be located in dielectric layer 104 . In some embodiments, part of the capacitor 118 may be located on the top surface TS of the dielectric layer 104 .

In addition, the details of each component in the capacitor structure 10 (eg, materials and forming methods, etc.) have been described in detail in the above-mentioned embodiments, and will not be further described here.

Based on the above-mentioned embodiments, in the capacitor structure 10 and its manufacturing method, since the shape of the electrode 106 a includes a grid shape, the electrode 106 a can have a larger surface area, thereby increasing the capacitance per unit area.

To sum up, in the capacitor structure and the manufacturing method thereof in the above embodiments, since the capacitor structure includes grid-like electrodes, the surface area of the electrodes can be increased, and thus the capacitance per unit area can be increased.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention should be defined by the scope of the appended patent application.

10: Capacitor structure 100: base 102: Pad 104: Dielectric layer 104a: Dielectric post 106, 110, 112, 114, 116: electrode material layer 106a, 110a, 112a, 114a, 116a: electrodes 108: dielectric material layer 108a: dielectric layer OP1, OP2: opening TS: top surface

1A to 1E are top views of the fabrication process of electrodes according to some embodiments of the present invention. 2A-2H are cross-sectional views of the fabrication process of capacitor structures according to some embodiments of the present invention.

10: Capacitor structure

100: base

102: Pad

104: Dielectric layer

106a, 110a, 112a, 114a, 116a: electrodes

108a: dielectric layer

OP2: opening

TS: top surface

Claims (10)

A capacitor structure comprising: base; and Capacitors, including: a first electrode disposed on the substrate, wherein the first electrode has a plurality of openings passing through the first electrode, and the shape of the first electrode includes a lattice shape; a second electrode disposed on the first electrode and filling a plurality of the openings; and The first dielectric layer is arranged between the first electrode and the second electrode. The capacitor structure of claim 1, wherein the second electrode comprises a single layer structure. The capacitor structure of claim 1, wherein the second electrode comprises a multilayer structure. The capacitor structure as described in claim 1, further comprising: A pad is disposed between the first electrode and the base, wherein the first electrode is electrically connected to the pad. The capacitor structure as described in claim 1, further comprising: A second dielectric layer is disposed on the substrate, wherein part of the capacitor is located in the second dielectric layer. A method of manufacturing a capacitor structure, comprising: provide the basis; and forming a capacitor on the substrate, wherein the capacitor comprises: a first electrode disposed on the substrate, wherein the first electrode has a plurality of openings passing through the first electrode, and the shape of the first electrode includes a lattice shape; a second electrode disposed on the first electrode and filling a plurality of the openings; and The first dielectric layer is arranged between the first electrode and the second electrode. The method for manufacturing a capacitor structure as claimed in item 6, wherein the method for forming the first electrode comprises: forming a second dielectric layer on the substrate; Forming lattice-shaped openings in the second dielectric layer, wherein the lattice-shaped openings penetrate through the second dielectric layer, so that the second dielectric layer has a plurality of dielectric columns, wherein the lattice-shaped openings surrounding a plurality of said dielectric pillars; forming an electrode material layer filling the lattice openings on the second dielectric layer, wherein the electrode material layer covers a plurality of the dielectric columns; and A part of the electrode material layer is removed to expose a plurality of the dielectric pillars, and the first electrode is formed. The method for manufacturing a capacitor structure as described in Claim 7, further comprising: A plurality of the dielectric posts are removed to form a plurality of the openings through the first electrode. The method for manufacturing a capacitor structure according to claim 6, wherein the method for forming the first dielectric layer and the second electrode comprises: conformally forming a layer of dielectric material over the first electrode and in the plurality of openings; forming a layer of electrode material on the layer of dielectric material, wherein the layer of electrode material fills a plurality of the openings; and The electrode material layer and the dielectric material layer are patterned to form the second electrode and the first dielectric layer. The method for manufacturing a capacitor structure as described in Claim 6, further comprising: Before forming the first electrode, a pad is formed on the substrate, wherein the first electrode is electrically connected to the pad.

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