WO2002003458A1 - Dispositif semi-conducteur et son procede de fabrication - Google Patents
Dispositif semi-conducteur et son procede de fabrication Download PDFInfo
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- WO2002003458A1 WO2002003458A1 PCT/JP2001/005663 JP0105663W WO0203458A1 WO 2002003458 A1 WO2002003458 A1 WO 2002003458A1 JP 0105663 W JP0105663 W JP 0105663W WO 0203458 A1 WO0203458 A1 WO 0203458A1
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- electrode
- insulating film
- lower electrode
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- forming
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- 239000004065 semiconductor Substances 0.000 title claims abstract description 142
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 101
- 239000000758 substrate Substances 0.000 claims abstract description 113
- 230000002093 peripheral effect Effects 0.000 claims abstract description 105
- 239000010410 layer Substances 0.000 claims description 383
- 238000000034 method Methods 0.000 claims description 133
- 239000011229 interlayer Substances 0.000 claims description 107
- 239000003990 capacitor Substances 0.000 claims description 60
- 238000000151 deposition Methods 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 10
- 239000004020 conductor Substances 0.000 claims description 9
- 238000000059 patterning Methods 0.000 claims description 5
- 210000004709 eyebrow Anatomy 0.000 claims 1
- 239000012212 insulator Substances 0.000 claims 1
- 238000009499 grossing Methods 0.000 description 96
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 83
- 229920005591 polysilicon Polymers 0.000 description 77
- 238000005530 etching Methods 0.000 description 60
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 43
- 238000000206 photolithography Methods 0.000 description 29
- 229910045601 alloy Inorganic materials 0.000 description 27
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- 229910004298 SiO 2 Inorganic materials 0.000 description 26
- 230000015572 biosynthetic process Effects 0.000 description 18
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
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- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
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Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B12/00—Dynamic random access memory [DRAM] devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
- H01L28/60—Electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
- H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body
- H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind
- H01L27/0805—Capacitors only
Definitions
- the present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly, to a semiconductor device having a capacitor mounted on a semiconductor substrate and a method of manufacturing the same.
- the semiconductor substrate 1 0 on is formed by laminating a first insulating film 1 2 and the second insulating film 1 6 consisting of S i-0 2 film or the like in order .
- a Ti layer, a Ti ON layer, a Ti layer, an A 1 Si layer, and a Ti N layer are sequentially deposited from the bottom to form a Ti N / A 1 — Form a SiZTi / TiON / Ti multilayer film.
- the upper electrode 22 is formed by Ti, TiN or the like.
- the Ti NZ A 1 —Si / Ti / TiO'N / Ti laminated film 18 is selectively etched and removed to a predetermined shape. Patterning to form lower electrode 18 d of Ti N / A 1 _ S i / T i / T i ON / T i laminated film o '
- the entire surface of the substrate including the upper electrode 22 and the lower electrode 18 d is formed by a plasma CVD method using, for example, TEOS (tetraeth o ⁇ ysi 1 ane; Si (0C 2 H 5 ) 4 ) as a raw material.
- TEOS tetraeth o ⁇ ysi 1 ane; Si (0C 2 H 5 ) 4
- a SiO2 film is deposited, and a S0G (Spin On Glass) film is coated on the Si02 film, and then the SOG film and the Si02 film are etched back.
- Perform smoothing processing That is, the unevenness on the surface of the base is filled with the smoothing insulating film 24 composed of the SiO 2 film and the S 0 G film and smoothed.
- the surface of the upper electrode 2 2 ′ formed on the lower electrode 18 d is located higher than the surface of the lower electrode 18 d.
- an interlayer insulating film 27 is formed by the smoothing insulating film 24 and the insulating film 26.
- the interlayer insulating film 27 on the upper electrode 22 is selectively etched away using a photolithography process and a dry (Dry) etching method, and the interlayer on the lower electrode 18 d is removed.
- Insulation film 2 7 The first and second via holes 28d and 28e are opened by selective etching and removal, respectively.
- the Tin of the surface of the lower electrode 18d is removed.
- the A1 alloy layer After depositing an A1 alloy layer on the entire surface of the substrate, the A1 alloy layer is processed by photolithography and dry etching to form first and second via holes 28d, 2d. First and second A1 alloy upper wiring layers 30d and 3Oe connected to the upper electrode 22 and the lower electrode 18d via 8e, respectively, are formed.
- first and second A1 alloy upper wiring layers 30d and 30e connected to the upper electrode 22 and the lower electrode 18d of the capacitive element, respectively, are formed by the first and second electrodes.
- the via holes 28 d and 28 e are respectively opened, the thickness of the interlayer insulating film 27 on the upper electrode 22 etched to open the first via hole 28 d is reduced.
- the first and second A1 alloy upper wiring layers 30 d and 30 d are formed from the opposing region of the upper electrode 22 and the lower electrode 18 d which effectively function as a capacitive element. Comparing the distances up to 30 e, the lower electrode side generally tends to be longer than the upper electrode side, resulting in a problem in that the impedance varies and the characteristics are asymmetric. .
- a comparison of the first and second via holes 28d and 28e in the above-described conventional capacitive element shows that the depth of the second via hole 28e on the lower electrode side is higher.
- the hole is deeper than the depth of 28 d. For this reason, the asymmetry of the conventional characteristics was further increased. Disclosure of the invention
- the present invention has been made in view of the above problems, and in the manufacturing process of the capacitor element, the characteristics such as the capacitance value fluctuate due to the damage to the upper electrode and the dielectric film during the manufacturing process. Of the capacitor element is prevented from deteriorating. It is an object of the present invention to provide a semiconductor device capable of realizing good characteristics and high reliability and a method for manufacturing the same.
- a semiconductor device includes a lower electrode having a concave cross-sectional shape formed on a semiconductor substrate with a first insulating film interposed therebetween, wherein a surface of a peripheral portion is higher than a surface of a central portion, and An upper electrode formed on the center of the electrode through a dielectric film whose surface is lower than the surface of the periphery of the lower electrode, and a second insulating film that fills the recess in the concave cross-sectional shape of the lower electrode It comprises.
- the surface is at a high position” or “the surface is at a low position” is an expression that refers to the height of the front surface with respect to the flat surface of the front or back surface of the semiconductor substrate. is there. This definition applies hereinafter as well.
- a third insulating layer is further formed on a peripheral portion of the lower electrode, the upper electrode, and the second insulating film to form an interlayer insulating film, and the opening is formed in the interlayer insulating film.
- a first wiring layer connected to the upper electrode via the first via hole, and a second wiring layer connected to the peripheral portion of the lower electrode via a second via hole opened in the interlayer insulating film. are formed respectively.
- a semiconductor device includes a lower electrode formed on a semiconductor substrate with a first insulating film interposed therebetween, and a lower electrode formed around the lower electrode.
- a dummy electrode having a surface higher than the surface of the lower electrode; an upper electrode formed on the lower electrode via a dielectric film whose surface is lower than the uppermost surface of the dummy electrode; and a dummy electrode.
- a second insulating film that fills the recess surrounded by the periphery.
- a dummy electrode having a surface higher than the surface of the dielectric film means that the top surface of the dummy electrode is higher than the surface of the lower electrode with reference to the flat surface of the front or back surface of the semiconductor substrate. It means that the uppermost surface I of the dummy electrode is the surface of the dummy electrode. The surface at the highest position. This definition applies hereinafter as well.
- the semiconductor device wherein a third insulating film is formed on the dummy electrode, the upper electrode, and the second insulating film to form an interlayer insulating film.
- a semiconductor device includes a lower electrode having a concave cross-sectional shape formed on a semiconductor substrate with a first insulating film interposed therebetween, wherein a surface of a peripheral portion is higher than a surface of a central portion, and The upper electrode, which is formed on the center of the electrode via a dielectric film and whose surface is lower than the surface of the lower electrode, fills the recess of the lower electrode with a concave cross-sectional shape, and the surface of the upper electrode And a second insulating film covering the first insulating film.
- a third insulating layer is formed on a peripheral portion of the lower electrode and on the second insulating film to form an interlayer insulating film, and the first via hole opened in the interlayer insulating film.
- a first wiring layer connected to the upper electrode through the hole and a second wiring layer connected to the peripheral portion of the lower electrode through the second via hole opened in the interlayer insulating film are formed.
- a semiconductor device includes: a lower electrode formed on a semiconductor substrate via a first insulating film; and a dummy electrode formed around the lower electrode and having a surface higher than the surface of the lower electrode. And an upper electrode formed on the lower electrode via a dielectric film and having a surface lower than the uppermost surface of the dummy electrode, and a hollow surrounded by the dummy electrode, and the lower electrode and the upper electrode. A second insulating film covering the surface of the electrode.
- the “dummy electrode having a surface higher than the surface of the lower electrode” means that the uppermost surface of the dummy electrode is higher than the surface of the lower electrode on the basis of the flat surface of the front or back surface of the semiconductor substrate. It means that it is high, and the “top surface of the dummy electrode” means the surface at the highest position among the surfaces of the dummy electrodes. This definition applies hereinafter as well.
- the present invention provides the semiconductor device according to the first aspect, wherein a third insulating film is formed on the dummy electrode, the upper electrode, and the second insulating film, an interlayer insulating film is formed, and an opening is formed in the interlayer insulating film.
- a first wiring layer connected to the upper electrode through the via hole and a second wiring layer connected to the lower electrode through the second via hole opened in the interlayer insulating film are formed.
- a dummy layer for a step is provided below the peripheral portion of the lower electrode, whereby the lower electrode has a concave cross-sectional shape.
- a dummy layer for a step is provided below the dummy electrode, whereby the dummy electrode is formed at a position higher than the lower electrode.
- Such a dummy layer for a step can be formed of the same material layer as an electrode or a resistance layer of another element in the semiconductor device.
- the dummy layer for the step can be formed of an insulating layer.
- the lower electrode has a concave cross-sectional shape in which the surface of the peripheral portion is higher than the surface of the central portion; Also, the surface of the dielectric film on the central portion of the lower electrode having the concave cross-sectional shape is the surface of the peripheral portion of the lower electrode.
- the second insulating film serving as a smoothing insulating film is formed over the entire surface of the base, Even when a smoothing process for etching back an insulating film or the like deposited on the entire surface of the substrate is performed, the periphery of the lower electrode becomes an etching stopper, and it is possible to prevent the dielectric film from being damaged. Therefore, it is possible to obtain a highly reliable capacitive element with little change in characteristics.
- a third insulating film is formed on a peripheral portion of the lower electrode, on the upper electrode, and on the second insulating film, and an interlayer insulating film is formed.
- the formation of the second wiring layer connected to the periphery of the lower electrode via the second via hole allows the interlayer insulation on the upper electrode to be etched for the opening of the first via hole.
- the thickness of the film is almost equal to the thickness of the interlayer insulating film on the periphery of the lower electrode to be etched for the opening of the second via holes.
- Excessive overetch on top electrode surface The dielectric film under the Oconnection upper electrode grayed can be prevented from being useless one di. Therefore, in addition to the above effects, a change in characteristics is further reduced, and a highly reliable capacitor can be obtained. Also, comparing the first and second via holes
- the depth of the second via hole opening on the periphery of the lower electrode is almost equal to the depth of the first via hole opening on the upper electrode, it effectively functions as a capacitive element Since the distance from the facing region between the upper electrode and the lower electrode to the first and second wiring layers is generally shorter on the lower electrode side, which tends to be longer than on the upper electrode side, the impedance is reduced. By reducing the difference, it is possible to suppress an increase in the asymmetry of the characteristic of the capacitor, and to improve the symmetry of the characteristic of the capacitor.
- a lower electrode, a dummy electrode formed around the lower electrode and having a surface higher than the surface of the lower electrode, and a dielectric film formed on the lower electrode The upper surface of the dielectric film on the lower electrode is lower than the uppermost surface of the dummy electrode around the lower electrode, so that the entire surface of the substrate becomes a smooth insulating film.
- the insulating film 2 even if a smoothing process is performed to etch back the insulating film deposited on the entire surface of the substrate, the dummy electrode becomes an etching stopper and the dielectric film is damaged. Can be prevented. Therefore, it is possible to obtain a highly reliable capacitive element with little change in characteristics.
- a lower electrode having a concave cross-sectional shape in which the surface of the peripheral portion is higher than the surface of the central portion is formed through the dielectric film on the central portion of the lower electrode.
- the periphery of the lower electrode will serve as an etching stopper, and the upper electrode and the dielectric under the upper electrode will also be etched.
- Body membrane is damaged It is possible to prevent that receive. Therefore, it is possible to obtain a highly reliable capacitive element with little variation in characteristics.
- the third insulating film is formed on the peripheral portion of the lower electrode and the second insulating film covering the surface of the upper electrode, and the interlayer insulating film is formed. Connected to the upper electrode via the first via hole opened in the interlayer insulating film on the upper electrode And a second wiring layer connected to the peripheral portion of the lower electrode through a second via hole opened in the interlayer insulating film on the peripheral portion of the lower electrode.
- the interlayer insulating film on the upper electrode to be etched for the opening of the first via hole is etched for the opening of the second via hole.
- the depth of the second via hole opening on the periphery of the lower electrode is greater than the depth of the first via hole opening on the upper electrode.
- the lower part which generally tends to be longer than the upper electrode side, at the distance from the opposing region of the upper electrode and the lower electrode, which effectively functions as a capacitive element, to the first and second wiring layers due to the shallowness. Since the distance on the electrode side is shortened, the difference in impedance is reduced, the increase in the asymmetry of the characteristics of the capacitor is suppressed, and the symmetry of the characteristics of the capacitor can be improved.
- the upper electrode on the lower electrode is lower than the top surface of the dummy electrode around the lower electrode, so that a smooth insulating film is formed on the entire surface of the substrate.
- the insulating film is formed, it is possible to easily realize that the surface of the upper electrode is covered with the second insulating film, so that the insulating film deposited on the entire surface of the base is etched back.
- the manufacturing can be simplified.
- a method of manufacturing a semiconductor device includes the steps of: forming a step-forming dummy layer of a predetermined thickness in a peripheral portion of a region where a capacitor element is to be formed on a semiconductor substrate via a first insulating film; After depositing a conductive film on the first insulating film and the dummy layer, the conductive film is subjected to buttering so that the surface of the peripheral portion is higher than the surface of the central portion.
- the present invention provides the method for manufacturing a semiconductor device, further comprising: forming a third insulating film on the entire surface of the substrate including the lower electrode, the upper electrode, and the second insulating film to form an interlayer insulating film. Opening a first via hole in the interlayer insulating film on the upper electrode, and opening a second via hole in the interlayer insulating film on the periphery of the lower electrode; Forming a first wiring layer connected to the upper electrode through the hole, and forming a second wiring layer connected to the peripheral portion of the lower electrode through the second via hole.
- a method of manufacturing a semiconductor device includes the steps of: forming a step-forming dummy layer of a predetermined thickness around a region where a capacitor element is to be formed on a semiconductor substrate via a first insulating film; After a conductive film is deposited on the first insulating film and the dummy layer, the conductive film is patterned to form a lower electrode in a region where a capacitor is to be formed, and to cover one layer of the dummy. Forming a dummy electrode having a surface higher than the surface of the lower electrode around the region where the capacitive element is to be formed; and forming a dielectric on the lower electrode at a position lower than the uppermost surface of the dummy electrode. A step of forming an upper electrode through the film; and a step of forming a second insulating film on the entire surface of the base to fill a depression surrounded by the dummy electrode.
- the present invention provides a method of manufacturing a semiconductor device, comprising: forming a third insulating film on the entire surface of the substrate including the dummy electrode, the upper electrode and the second insulating film to form an interlayer insulating film; Opening a first via hole in the interlayer insulating film and opening a second via hole in the interlayer insulating film on the lower electrode, and connecting to the upper electrode via the first via hole Forming a first wiring layer and forming a second wiring layer connected to the lower electrode via a second via-hole.
- the method of manufacturing a semiconductor device includes a step of forming a step-like dummy layer having a predetermined thickness at a peripheral portion of a region where a capacitor element is to be formed on a semiconductor substrate via a first insulating film. After depositing a conductor film on the first insulating film and the dummy layer, the conductor film is patterned to form a lower portion having a concave cross-sectional shape in which the surface of the peripheral portion is higher than the surface of the central portion.
- the present invention provides the method for manufacturing a semiconductor device according to the above method, further comprising: forming a third insulating film on a peripheral portion of the lower electrode and the entire surface of the substrate including the second insulating film to form an interlayer insulating film; Forming a first via hole in the interlayer insulating film, and opening a second via hole in the interlayer insulating film on the periphery of the lower electrode; and forming the first via hole through the first via hole. Forming a first wiring layer connected to the upper electrode, and forming a second wiring layer connected to the peripheral portion of the lower electrode via the second via hole.
- a method of manufacturing a semiconductor device includes the steps of: forming a step-forming dummy layer of a predetermined thickness around a region where a capacitor element is to be formed on a semiconductor substrate via a first insulating film; After depositing a conductive film on the first insulating film and the dummy layer, the conductive film is patterned to form a lower electrode in a region where a capacitor is to be formed, and a dummy layer is formed. Forming a dummy electrode having a surface higher than the surface of the lower electrode around the area where the capacitive element is to be formed; and forming a dummy electrode on the lower electrode via a dielectric film from the uppermost surface of the dummy electrode. Forming a second insulating film over the entire surface of the substrate to fill the cavities surrounded by the dummy electrode, and to form a surface of the lower electrode and the upper electrode. Covering with o
- the present invention provides the method of manufacturing a semiconductor device, further comprising forming a third insulating film on the entire surface of the substrate including the third insulating film on the entire surface of the substrate including the dummy electrode and the second insulating film, thereby forming an interlayer insulating film.
- the step of forming the dummy layer for a step can also serve as the step of forming an electrode or a resistance layer of another element in the semiconductor device.
- the dummy layer for the step can be formed of an insulating layer.
- a dummy for a step having a predetermined thickness is formed at a peripheral portion of a region where a capacitive element is to be formed on a semiconductor substrate via a first insulating film.
- the conductive film deposited on one layer is patterned to form a concave-shaped lower section where the peripheral surface is higher than the central surface, and the electrode is formed in the area where the capacitive element is to be formed.
- the third insulating film is formed on the entire periphery of the base including the lower electrode, the upper electrode, and the second insulating film to form an interlayer insulating film.
- a first wiring layer connected to the upper electrode through a first via hole opened in the interlayer insulating film on the upper electrode is formed, and an opening is formed in the interlayer insulating film on the peripheral portion of the lower electrode.
- the over-etching of the upper electrode due to excessive over-etching to the surface of the upper electrode is performed because the film thickness is almost the same as the interlayer insulating film on the side. This can prevent the dielectric film from being damaged. Therefore, in addition to the effects described above, a highly reliable capacitive element with less variation in characteristics can be obtained.
- the depth of the second via opening on the lower electrode is approximately equal to the depth of the first via hole opening on the upper electrode.
- the distance from the lower electrode side, which generally tends to be longer than the upper electrode side, in the distance from the opposing region of the upper electrode and the lower electrode, which effectively functions as a capacitive element, to the first and second wiring layers is Therefore, the difference in impedance can be reduced to suppress an increase in the asymmetry of the characteristic of the capacitor, and the symmetry of the characteristic of the capacitor can be improved.
- the method for manufacturing a semiconductor device after forming a step-forming single layer of a predetermined thickness around a region where a capacitor is to be formed on a semiconductor substrate via a first insulating film, The first insulating film and the dummy are patterned on the conductor film deposited on one layer to form a lower electrode in a region where a capacitive element is to be formed, and a dummy layer is coated, and a surface higher than the surface of the lower electrode is formed.
- a dummy layer for a step having a predetermined thickness is formed at a peripheral portion of a region where a capacitor is to be formed on a semiconductor substrate with a first insulating film interposed therebetween.
- a lower electrode having a concave cross-sectional shape in which the surface of the peripheral portion is higher than the surface of the central portion is formed in the capacitor element formation region.
- the upper electrode is formed on the entire surface of the base by forming an upper electrode at a position lower than the surface of the peripheral portion of the lower electrode on the center of the lower electrode via a dielectric film.
- the surface of the upper electrode can be easily covered with the second insulating film, even when the second insulating film serving as the smoothing insulating film is formed, even if the entire surface of the base is formed. Smoothing process to etch back the insulating film deposited on Even if the upper electrode is etched, the surface of the upper electrode is etched and the upper electrode and the dielectric film under the upper electrode are damaged. Can be prevented. Therefore, it is possible to obtain a highly reliable capacitive element with little change in characteristics.
- a third insulating film is formed on the entire surface of the base including the peripheral portion of the lower electrode and the second insulating film covering the surface of the upper electrode, thereby forming an interlayer insulating film.
- a first wiring layer connected to the upper electrode through a first via opening in the interlayer insulating film on the upper electrode is formed, and an interlayer insulating film on a peripheral portion of the lower electrode is formed.
- a second wiring layer connected to a peripheral portion of the lower electrode through a second via hole opened in the upper layer an interlayer insulation on the upper electrode etched for opening the first via hole is formed.
- the film becomes thicker than the interlayer insulating film on the periphery of the lower electrode to be etched for the opening of the second via holes.
- Excessive overshoot on top electrode surface I go-between the upper electrode and further that the etching It is possible to prevent the lower dielectric film from being damaged. Therefore, in addition to the above-described effects, a highly reliable capacitive element with less variation in characteristics can be obtained.
- the depth of the second via hole opening on the lower electrode is smaller than the depth of the first via hole opening on the upper electrode.
- the distance from the opposing region of the upper electrode and the lower electrode, which effectively functions as a capacitive element, to the first and second wiring layers is generally longer on the lower electrode side than on the upper electrode side. Since the separation is shortened, the difference in impedance can be reduced to suppress an increase in the asymmetry of the characteristic of the capacitive element, and the symmetry of the characteristic of the capacitive element can be improved.
- a dummy layer for a step having a predetermined thickness through a first insulating film around a region where a capacitor is to be formed on a semiconductor substrate After forming a dummy layer for a step having a predetermined thickness through a first insulating film around a region where a capacitor is to be formed on a semiconductor substrate, The first insulating film and the conductive film deposited on one layer of the dummy are patterned to form a lower electrode in a region where a capacitive element is to be formed.
- a dummy electrode having a high surface is formed around the area where the capacitive element is to be formed, and an upper electrode having a lower surface than the uppermost surface of the dummy electrode is formed on the lower electrode via a dielectric film.
- the second insulating film By forming the second insulating film, it is possible to easily realize that the surface of the upper electrode is covered with the second insulating film formed on the entire surface of the base.
- the upper electrode and the dielectric film below it may be damaged in harmony with that one electrode becomes the etching stopper. Can be prevented. Therefore, it is possible to obtain a highly reliable capacitive element with little change in characteristics.
- the step —Since the step of forming a layer also serves as the step of forming an electrode or a resistive layer of another element in the semiconductor device, the manufacturing process can be simplified.
- FIG. 1 is a schematic sectional view showing a capacitive element according to a first embodiment of the present invention.
- FIG. 2 is a schematic process sectional view (part 1) for explaining a method of manufacturing the capacitive element shown in FIG.
- FIG. 3 is a schematic process sectional view (part 2) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 4 is a schematic process sectional view (part 3) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 5 is a schematic process sectional view (part 4) for explaining a method of manufacturing the capacitive element shown in FIG.
- FIG. 6 is a schematic process sectional view (part 5) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 7 is a schematic process sectional view (part 6) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 8 is a schematic process sectional view (part 7) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 9 is a schematic process sectional view (part 8) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 10 is a schematic sectional view showing a capacitive element according to the second embodiment of the present invention.
- FIG. 11 is a schematic process sectional view (part 1) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 12 is a view for explaining a method of manufacturing the capacitive element shown in FIG. 10.
- FIG. 2 is a schematic process sectional view (No. 2).
- FIG. 13 is a schematic sectional view showing a capacitive element according to the third embodiment of the present invention.
- FIG. 14 is a schematic process cross-sectional view (part 1) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 15 is a schematic process sectional view (part 2) for describing the method for manufacturing the capacitive element shown in FIG.
- FIG. 16 is a schematic step-by-step cross-sectional view (part 3) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 17 is a schematic process sectional view (part 4) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 18 is a schematic step-by-step cross-sectional view (part 5) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 19 is a schematic process sectional view (part 6) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 20 is a schematic sectional view showing a capacitive element according to the fourth embodiment of the present invention.
- FIG. 21 is a schematic process cross-sectional view (part 1) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 22 is a schematic process sectional view (part 2) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 23 is a schematic process sectional view (part 3) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 24 is a schematic step-by-step cross-sectional view (part 4) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 25 is a schematic step-by-step cross-sectional view (part 5) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 26 is a view for explaining a method of manufacturing the capacitive element shown in FIG. 20.
- FIG. 6 is a schematic process sectional view (No. 6).
- FIG. 27 is a schematic step-by-step cross-sectional view (part 7) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 28 is a schematic process sectional view (part 8) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 29 is a schematic sectional view showing a capacitive element according to the fifth embodiment of the present invention.
- FIG. 30 is a schematic step-by-step cross-sectional view (No. 1) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 31 is a schematic step-by-step cross-sectional view (part 2) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 32 is a schematic sectional view showing a capacitor according to a sixth embodiment of the present invention.
- FIGS. 33A and 33B are schematic process sectional views (No. 1) for explaining the method of manufacturing the capacitive element shown in FIG.
- FIG. 34 is a schematic step-by-step cross-sectional view (part 2) for describing the method for manufacturing the capacitive element shown in FIG. 32.
- FIG. 35 is a schematic step-by-step cross-sectional view (part 3) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 36 is a schematic step-by-step cross-sectional view (part 4) for describing a method of manufacturing the capacitive element shown in FIG.
- FIG. 37 is a schematic step-by-step cross-sectional view (part 5) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 38 is a schematic process sectional view (part 6) for describing the method of manufacturing the capacitive element shown in FIG.
- FIG. 39 is a schematic process sectional view (part 1) for explaining a conventional method of manufacturing a capacitive element.
- FIG. 40 shows schematic steps for explaining a conventional method of manufacturing a capacitive element. It is sectional drawing (2).
- FIG. 41 is a schematic process sectional view (part 3) for describing the conventional method of manufacturing a capacitive element.
- FIG. 1 is a schematic sectional view showing a capacitive element according to a first embodiment of the present invention.
- FIGS. 2 to 9 are schematic sectional views for explaining a method for manufacturing the capacitive element shown in FIG. is there.
- the peripheral part of the capacitive element formation region on the semiconductor substrate 10 is provided via a first insulating film 12 made of, for example, a SiO 2 film.
- a polycrystalline silicon layer 14 for a step made of a polysilicon (Po1ySi1icon) layer having a required thickness, for example, a thickness of about 100 to 500 nm is formed.
- a second insulating film 16 is formed on the first insulating film 12 and the polysilicon dummy layer 14. Note that the second insulating film 16 can be omitted.
- a Ti layer having a thickness of about 5 to 70 nm, a Ti 0 N layer having a thickness of about 10 to 20 nm, and a thickness of 5 to 7 nm are provided on the second insulating film 16.
- a Ti layer with a thickness of about 0 nm, an A1-Si layer with a thickness of about 300 to 150 nm, and a TiN layer with a thickness of about 5 to 70 nm were deposited in order from the bottom.
- the lower electrode 18a is formed by a TiNZAl-Si / Ti / TiONZTi laminated film, or by Cu, A1_Cu, or the like. In this example, the lower electrode 18a of the TiNZAl-Si / Ti / TiON / Ti stacked film is formed.
- the surface of the peripheral part above the dummy layer 14 is, for example, about 100 to 500 nm higher It is in. .
- the uppermost Ti ⁇ layer is formed by a film formed during the manufacturing process. It functions as an anti-reflection film and a lower anti-oxidation film of the A 1 —Si layer under the process of the trilithography, and the A 1 —S i layer functions as a main part of the electrode which needs to have a conductive property.
- the ⁇ i 0 N / Ti laminated film functions as a barrier metal.
- the dielectric film such as S i 0 2 or S i N 2 0, via the dielectric film of T a 2 0 5 in the present example, the thickness of 5 ⁇ 1 0 0 nm approximately T i, T i N or T i and T i N upper electrode 2 composed of a laminated film of 2 are formed.
- the dielectric film 2 0 when formed by S i 0 2, S i N and the like, may be formed of a laminated film of the upper portion electrode 2 2 Ding 1, T i N or ⁇ ⁇ ⁇ and T i.
- the surface of the upper electrode 22 formed on the central portion of the lower electrode 18a having the concave cross-sectional shape of the capacitive element is formed of a polysilicon layer of the lower electrode 18a having the concave cross-sectional shape. (4) The height is lower than the surface of the peripheral part above.
- a smoothing process is performed on the irregularities on the surface of the substrate composed of the upper electrode 22 and the lower electrode 18a. That is, for example, Si 0 deposited on the entire surface of the substrate using a plasma CVD method using TE 0 S as a raw material.
- a smoothing insulating film 24 made of a film and an S 0 G film coated thereon is formed, and the smoothing insulating film 24 fills the concave portion of the lower electrode 18 a having a concave cross-sectional shape.
- the surface of the upper electrode 22 is covered.
- an insulating film 26 made of, for example, a SiO film is deposited on the entire surface of the smoothed substrate, that is, on the periphery of the lower electrode 18a and on the smoothing insulating film 24.
- An interlayer insulating film 27 is formed by the smoothing insulating film 24 and the insulating film 26.
- a first upper wiring layer 30a made of one alloy layer is formed. Further, for example, an A1 alloy layer connected to the peripheral portion of the lower electrode 18a through a second via hole 28b opened in the interlayer insulating film 27 on the peripheral portion of the lower electrode 18a. A second upper wiring layer 30b is formed.
- a first insulating film 12 made of, for example, a SiO film is formed on a semiconductor substrate 10, and then a first insulating film 12 is made of, for example, polysilicon. Make the silicon layer the required thickness, for example
- the polysilicon layer is selectively etched and removed to form a predetermined shape.
- a polysilicon layer having a thickness of about 100 to 500 nm is formed around the semiconductor element 10 on the periphery of the area where the capacitive element is to be formed, with the first insulating film 12 interposed therebetween.
- Step dummy polysilicon layer 14 is formed.
- the process of forming the polysilicon layer 14 is the same as that of the LSI.
- Other elements such as MOS Gate (Mate Oxide Semiconductor Transistor) gate electrodes, resistive element resistance layers, and Bip Tr (Bipo 1 ar Transistor) electrodes. It can be used also as a process of forming a polysilicon layer to be used.
- a second insulating film 16 is formed on the entire surface of the substrate including the polysilicon layer 14 for the step. Note that the formation of the second insulating film 16 can be omitted.
- a conductive film having a required thickness for example, a Ti layer having a thickness of about 5 to 70 nm is formed on the second insulating film 16 by using, for example, a sputtering method.
- T i 0 N layer with a thickness of about 10 to 20 O nm T i layer with a thickness of about 5 to 7 O nm
- a TiN layer having a thickness of about 5 to 70 nm is sequentially deposited from the bottom to form a TiN / Al-Si / Ti / TiONZTi multilayer film 18.
- the uppermost TiN layer functions as an antireflection film in the photolithography process during the manufacturing process and as an antioxidant film for the A1—Si layer thereunder.
- the A 1 —S i layer functions as a main part of the electrode that requires conductive characteristics, and the underlying T i / T i 0 N / T i stacked film functions as a barrier metal.
- the surface above the polysilicon / dummy layer 14 for a step having a thickness of about 100 to 500 nm is formed.
- the height is about 100 to 500 nm higher than the surface in the region surrounded by the polysilicon layer 14.
- the CVD method is used to form T a0, T i N / A 1 on the S i / T i / T i 0 N / T i laminated film 18.
- S i 0, S i N, etc., in this example T a 2 0 5 dielectric Deposit the film to a required thickness, for example, about 10 to 300 nm
- a conductor layer of a Ti layer, a TiN layer or a laminated film of Ti and TiN is deposited to a required thickness, for example, a thickness of about 5 to 100 nm.
- the thus-stacked conductive layer and dielectric film are selectively etched away and patterned into a predetermined shape.
- the thickness of the TiNNZAl—Si / Ti / TiON / Ti stacked film 18 in the area surrounded by the polysilicon layer 14 for the step is formed to a thickness of 10 Thickness 5 to 300 nm through dielectric film 20 of about 300 nm
- An upper electrode 22 composed of a Ti layer, a TiN layer of about 100 nm, or a laminated film of Ti and TiN is formed.
- the surface of the upper electrode 22 is lower in height than the surface above the polysilicon ⁇ dummy layer 14 of the laminated film 18.
- the TiN / Al-Si / Ti / TiON / Ti stacked film 18 is selectively etched away and patterned into a predetermined shape.
- the recessed cross-section T i N / is located at a position where the surface of the peripheral portion above the polysilicon for the step is higher than the surface of the central portion where the upper electrode 22 is formed.
- the lower electrode 18a is formed by the Al-Si / Ti / TiONZTi multilayer film. Simultaneously with the formation of this lower electrode 18a, the lower wiring layer (not shown) of the other elements of the LSI is formed by the TiN / A1-Si / Ti / TiON / Ti stacked film.
- a capacitive element composed of the upper electrode 22 and the lower electrode 18a sandwiching the dielectric film 20 is formed.
- the surface of the upper electrode 22 of the constriction element is lower in height than the surface of the peripheral portion of the lower electrode 18a above the polysilicon layer 14 of the lower layer.
- a smoothing process for smoothing unevenness on the entire surface of the substrate is performed. That is, for example, plasma using TEOS as a raw material
- an SiO 2 film is deposited to a thickness of about 300 to 150 nm on the entire surface of the base including the upper electrode 22 and the lower electrode 18a. Further, an SOG film is coated on the SiO 2 film. Thereafter, the S 0 G film and the S i O 2 film are etched back.
- a smoothing insulating film 24 for filling the surface of the upper electrode 22 and smoothing the entire surface of the base is formed while filling the recess of the concave cross-sectional shape of the lower electrode 18a.
- the surface of the upper electrode 22 formed on the central portion of the lower electrode 18a having the concave cross section is The height of the lower electrode 18a of the concave cross-sectional shape is lower than the surface of the peripheral portion above the polysilicon.
- S i 0 2 and T for etching rate between i and T i N does not change rather large, after the formation of the S 0 G film and S i 0 2 film During the etch back, the surface of the lower electrode 18a is exposed, but the surface of the upper electrode 22 is always covered with the smoothing insulating film 24. There is no exposure. That is, the upper electrode 22 and the dielectric film 20 thereunder are not damaged.
- the insulating film 2 made of, for example, a SiO 2 film is formed on the entire base including the peripheral portion of the lower electrode 18 a and the smoothing insulating film 24. Deposit 6 smooth The insulating insulating film 24 and the insulating film 26 form an interlayer insulating film 27.
- the interlayer insulating film 27 on the upper electrode 22 is selectively removed by etching using photolithography and dry etching, and the interlayer insulating film on the periphery of the lower electrode 18a is removed.
- 2 7 is selectively etched away, and the first and second via holes 28 a
- the TiN layer on the surface of the lower electrode 18a may be removed.
- the upper portion to be etched to open the first via hole 28a The total thickness of the interlayer insulating film 7 on the electrode 22 is smaller than the thickness of the interlayer insulating film 27 on the periphery of the lower electrode 18a etched to open the second via ⁇ hole 28b. Since the first and second via holes 28a and 28b are opened, excessive overetching of the surface of the upper electrode 22 is not performed.
- the A1 alloy layer is processed using a photolithography process and a drying method.
- a first and second vias A first alloy layer made of an A1 alloy layer connected to the peripheral portions of the upper electrode 22 and the lower electrode 18a via the holes 28a and 28b, respectively.
- First and second upper wiring layers 30a and 30b are formed.
- upper wirings (not shown) of other elements of the LSI are formed.
- a step formed of a polysilicon layer having a thickness of about 100 to 500 nm is formed on the semiconductor substrate 10 around a region where a capacitor element is to be formed, via a first insulating film 12.
- ⁇ Dummy layer 14 is formed, and this polysilicon dummy shoulder 14
- a second insulating film 16 is formed on the entire surface of the base including the semiconductor substrate, and the surface of the peripheral portion above the polysilicon / dummy layer 14 is higher on the second insulating film 16 than the surface of the central portion.
- a lower electrode 18a having a concave cross-sectional shape is formed at the same time, and a required thickness, for example, a dielectric film 20 having a thickness of about 10 to 300 nm
- An upper electrode 22 having a thickness of, for example, about 5 to 100 nm is formed, and the height of the surface of the upper electrode 22 is adjusted to a level above the polysilicon / dummy layer 14 of the lower electrode 18a.
- the smoothing process is performed by depositing a SiO 2 film over the entire surface of the substrate, further coating the SOG film, and then etching back, the concave shape of the lower electrode 18 a
- the smoothing insulating film 24 which fills the recesses of the cross-sectional shape and smoothes the entire surface of the substrate, always covers the surface of the upper electrode 22.
- the by the etching in the smoothing processing connexion upper electrode 2 2 or more does not Yuden film 7.20 thereunder damaged. Accordingly, it is possible to obtain a capacitor having good characteristics and high reliability by suppressing fluctuations in characteristics such as the capacitance value of the capacitor and deterioration in reliability.
- first and second vias are formed to form first and second upper wiring layers 30a and 30b connected to the upper electrode 22 and the lower electrode 18a of the capacitive element, respectively.
- the holes 28a and 28b are respectively opened, the total thickness of the interlayer insulating film 27 on the upper electrode 22 etched to open the first via hole 28a is Step 2 ⁇ Since the thickness of the interlayer insulating film 27 on the periphery of the lower electrode 18 a to be etched to open the hole 28 b is larger than that of the upper electrode 22, it is excessively large. such over-etching is not be performed, the upper electrode 2 2 and the underlying T a 2 0 5 dielectric film 2
- the depth of the second via hole 28 b opening on the lower electrode 18 a is higher than the upper electrode 22.
- the first and second electrodes 18 a Since it is shallower than the depth of the first via hole 28 a that opens to the first electrode, the first and second electrodes 18 a from the opposing region between the upper electrode 22 and the lower electrode 18 a that function effectively as a capacitive element In the distance to the second upper wiring layer 30a, 3'0b, the distance on the lower electrode side, which generally tends to be longer than that on the upper electrode side, is reduced, so that the difference in impedance is reduced.
- an increase in the asymmetry of the characteristics of the capacitor can be suppressed. That is, the symmetry of the characteristics of the capacitor can be improved.
- FIG. 10 is a schematic cross-sectional view showing a capacitive element according to the second embodiment of the present invention.
- FIGS. 11 and 12 are diagrams for explaining a method of manufacturing the capacitive element shown in FIG. 10. It is a schematic process sectional drawing.
- the same components as those of the first embodiment shown in FIGS. 1 to 9 shown in FIGS. 1 to 9 are denoted by the same reference numerals, and description thereof is omitted.
- an insulating dummy layer made of Si02 or the like, for example, a SiN dummy layer 32 for a step consisting of a SiN layer having a thickness of about 100 to 50 O nm is formed.
- Other components are the same as those in the first embodiment.
- step 1 This will be described with reference to a schematic sectional view of step 1 2.
- a first insulating film 12 made of, for example, a SiO 2 film is formed on a semiconductor substrate 10
- an insulating film different from the first insulating film 12 for example, a SiN film is formed to a thickness of about 100 to 500 nm.
- the SiN film is selectively removed by etching, and patterned into a predetermined shape.
- an S-N film having a thickness of about 100 to 50 O nm is formed around the semiconductor element 1 G around the area where the capacitor is to be formed, via the first insulating film 12.
- An iN dummy layer 32 is formed.
- a second insulating film is formed on the entire surface of the substrate including the SiN dummy layer 32. Then, a TiN / Al-Si / Ti / TiON / Ti laminated film 18 is formed on the second insulating film 16 and the TiNZA1 is formed.
- An upper electrode 22 is formed on the S i / T i ZT i 0 NZT i laminated film 18 via a dielectric film 20, and a Ti N / A l is formed by a photolithography process and an RIE process.
- T i / T i 0 NXT i laminated film 18 so that the surface of the peripheral part above the SiN dummy layer 32 is higher than the surface of the central part where the upper electrode 22 is formed.
- a lower electrode 18a having a certain concave cross-sectional shape is formed.
- the surface of the upper electrode 22 of the capacitive element is lower in height than the surface of the peripheral portion of the lower electrode 18a above the SiN dummy layer 32.
- a smoothing process for etching back the S 0 G film and the SiO 2 film was performed, and the lower electrode 18 a was formed. Fill the recess of the concave cross section and The surface of the electrode 22 is covered to form a smoothing insulating film 24 for smoothing the entire surface of the substrate.
- the surface of the upper electrode 22 formed on the center of the lower electrode 18a having the concave cross section is Lower electrode with concave cross section
- the height is lower than the surface of the peripheral portion above the 18 Na dummy layer 32 of 18a.
- the difference in etch rate between S i 0 2 and T i, T i N is not large. Therefore, even when the S 0 G film and the S i 0 film are etched back, the lower electrode 1 Although the surface of the periphery of 8a is exposed, the surface of the upper electrode 22 is always covered with the smoothing insulating film 24 and is not exposed by etching.
- an insulating film 26 made of, for example, an Sio film is deposited on the entire surface of the base including the lower electrode 18a and the peripheral portion including the smoothing insulating film 24 to form the smoothing insulating film 24 and the insulating film 2. 6 to form an interlayer insulating film 2 7
- the interlayer insulating film 27 on the upper electrode 22 is selectively etched and removed, and the interlayer insulating film 27 on the peripheral portion of the lower electrode 18a is selectively etched and removed. Open the second via and the holes 28a and 28b, respectively.
- the TiN layer on the surface of the lower electrode 18a may be removed.
- the total thickness of the interlayer insulating film 27 on the upper electrode 22 to be etched to open the first via hole 28 a is such that the second via hole 28 b is opened. Because the thickness of the interlayer insulating film 26 on the periphery of the lower electrode 18a to be etched is larger than that of the first and second via holes 28a and 28b, At this time, excessive overetching of the surface of the upper electrode 22 is not performed.
- a required thickness for example, 100 to 50, is provided on the semiconductor substrate 10 at the peripheral portion of the region where the capacitor element is to be formed via the first insulating film 12.
- a second insulating film 16 is formed on the entire surface of the substrate including the SiN dummy layer 32, and a second insulating film 16 is formed on the second insulating film 16 so as to be higher than the central surface.
- the lower electrode 18a having a concave cross-sectional shape in which the surface of the peripheral portion above the N dummy layer 32 is located at a high position is formed, and the upper electrode 22 is formed on the central portion thereof via the dielectric film 20. Then, the height of the surface of the upper electrode 22 is made lower than the height of the surface of the peripheral portion of the lower electrode 18a above the SiN dummy layer 32, whereby the Si S2 film is formed on the entire substrate.
- a smoothing insulating film 24 for filling the recesses of the concave cross-sectional shape of the lower electrode 18a and smoothing the entire surface of the substrate. Since the surface always covers the surface of the upper electrode 22, the etching at the time of this smoothing treatment induces the upper electrode 22 and further below the upper electrode 22. It does not receive the body film 2 0 Hurghada menu temporarily. Therefore, similarly to the case of the first embodiment, it is possible to suppress the fluctuation of the characteristics such as the capacitance value of the capacitance element and the deterioration of the reliability, and to obtain the capacitance element having good characteristics and high reliability. .
- first and second via holes for forming first and second upper wiring layers 30a and 30b connected to the upper electrode 22 and the lower electrode 18a of the capacitive element, respectively.
- the total thickness of the interlayer insulating film 27 on the upper electrode 22 etched to open the first via hole 28 a is the second thickness.
- the lower electrode 18a to be etched to open the via hole 28b is thicker than the interlayer insulating film 27 on the periphery of the lower electrode 18a.
- excessive over-etching on the surface of the upper electrode 22 is not performed, and the upper electrode 22 and the dielectric film 20 thereunder are not damaged. Therefore, as in the case of the first embodiment, fluctuations in characteristics such as the capacitance value of the capacitance element and deterioration in reliability are further suppressed, and a capacitance element having better characteristics and higher reliability is realized. Obtainable.
- the depth of the second via hole 28 b opening on the lower electrode 18 a is shallower than the depth of the first via hole 28 a opening on the upper electrode 22.
- the distance from the opposing region of the upper electrode 22 and the lower electrode 18a that effectively functions as a capacitive element to the first and second upper wiring layers 30a and 30b is from the upper electrode side. Therefore, as in the case of the first embodiment, the difference in impedance is reduced to increase the asymmetry of the characteristics of the capacitive element, as in the first embodiment. Thus, the symmetry of the characteristics of the capacitor can be improved.
- a required thickness for example, a thickness of 100 to 100 ⁇ m, is provided on the semiconductor substrate 10 around the region where the capacitive element is to be formed, via the first insulating film 12.
- the SiN dummy layer 32 for the step of about 500 nm is formed, instead of forming the SiN dummy layer 32, a photolithography process and an etching process are used.
- the first insulating film 12 in the central portion of the region where the capacitor is to be formed on the semiconductor substrate 10 is selectively etched away to form a recess having a depth of about 100 to 500 nm. Good.
- a final dummy layer is formed by a combination of the selective etching of the first insulating film 12 and the dummy layer 32 (or the dummy layer 14, which will be described later).
- a depression having a depth of about 100 to 500 nm can also be formed.
- a second insulating film 16 is formed in the same manner as in the second embodiment, and on the second insulating film 16, T i N / A l -S i ZT
- the i / TiON / Ti laminated film 18 By forming the i / TiON / Ti laminated film 18 and patterning the TiN / A1—Si / Ti / Ti0N / Ti laminated film 18 It is possible to form the lower electrode 18a having a concave cross-sectional shape in which the surface of the peripheral portion is higher than the surface of the central portion above the depression formed in the first insulating film 12. Therefore, the same operation and effect as those of the second embodiment can be obtained. (Third embodiment)
- FIG. 13 is a schematic cross-sectional view showing a capacitive element according to the third embodiment of the present invention.
- FIGS. 14 to 19 are each for explaining a method of manufacturing the capacitive element shown in FIG. FIG.
- the same elements as those of the first embodiment, which are not shown in FIGS. 1 to 9 and which are the same as those of the capacitive element, are denoted by the same reference numerals and description thereof is omitted. .
- a polysilicon for a step is provided at a peripheral portion of the capacitor.
- a polysilicon layer for the same thickness for example, a thickness of about 100 to 50 O nm.
- a dummy layer 34 is formed around the capacitive element. There is a special feature in this.
- the surface is flat.
- the lower electrode 18 b of T i N / A l — S i / T i / T i O NZT i is formed, and is separated from the lower electrode 18 b to form a step around the capacitance element.
- a dummy of Ti N / A 1 S i / T i / T i ONZT i having a surface higher than the surface of the upper electrode 22 above the polysilicon layer 34 for use
- the electrode 18c is formed.
- the smoothing insulating film 24 filling the recess of the concave cross-sectional shape of the lower electrode 18a covers the surface of the upper electrode 22.
- the smoothing insulating film 24 filling the depression surrounded by the dummy electrode 18c is formed on the upper electrode 22 formed on the lower electrode 18b. The surface is covered.
- the other components are substantially the same as those in the first embodiment.
- a polysilicon layer is formed on the first insulating film 1 2. to a required thickness, for example, a thickness of about 100 to 500 nm. Subsequently, the polysilicon layer is selectively removed by etching and patterned into a predetermined shape by a photolithography process and a RIE process.
- a polysilicon / dummy layer 34 for a step formed of a polysilicon layer having a thickness of about 100 to 50011 m is formed via the first insulating film 12.
- the process of forming the polysilicon 'dummy layer 34 is performed by using the other elements of the LSI, for example, the gate electrode of the MOST r, the resistance layer of the resistance element, and the polysilicon used as the electrode of the Bip Tr. It can also be used as a silicon layer forming process.
- the entire surface of the substrate including the polysilicon / dummy layer 34 for the step is A second insulating film 16 is formed. Insulating film 16 can also be omitted. Then, on this second insulating film 16, a TiN / A1_Si / Ti / TiON / Ti laminated film, or laminated by Cu, A1—Cu, or the like.
- a Ti N / A 1 S i / T i / T i ONZT i laminated film 18 is formed, and this T i N / A l-S i / T i / T i ON / T i On the laminated film 18, T a 2 ⁇
- the surface of the upper electrode 22 is made of polysilicon of the TiN / A 1 -SiZTi / Ti0N / Ti stacked film 18.
- the height is lower than the top surface above.
- the TiN / Al-Si / Ti / TiON / Ti stacked film 18 is selectively etched by a photolithography process and an RIE process. It is removed and buttered to a predetermined shape.
- the lower electrode 18 b of Ti N / A l —S i / T i / T i ON / T i is formed in the area where the capacitive element is to be formed on the second insulating film 16.
- a Ti Separately from the lower electrode 18b, a Ti having a top surface higher than the surface of the lower electrode 18b above the polysilicon / dummy layer 34 around the area where the capacitor is to be formed.
- a new electrode 18 c is formed by NZ T i.
- a lower wiring layer (not shown) is formed by a TiN / Al-SiZTiZTiON / Ti multilayer film of other elements of the LSI. .
- the surface of the upper electrode 22 of the capacitive element is formed by the polysilicon of the dummy electrode 18 c around the capacitive element forming region. 4 Its height is lower than the top surface above.
- the substrate entire surface including the upper electrode 2 2 and the lower electrode 1 8 b depositing a S i 0 2 film to a thickness of 3 0 0 ⁇ 1 5 0 0 nm extent . Furthermore, the S i 0 2 film, S 0 G film co Solo tee ring. Thereafter, a smoothing process for etching back the SOG film and the SiO 2 film is performed.
- the hollow surrounded by the dummy electrode 18c is buried, and the surface of the upper electrode 22 and the lower electrode 18b is covered to smooth the entire surface of the substrate.
- a film 24 is formed.
- the surface of the upper electrode 22 formed on the lower electrode 18b is damaged by the dummy around the capacitive element formation region. Therefore height than the uppermost surface of the poly silicon-dummy layer 3 4 upper electrode 1 8 c is summer low, even when the etch-back of S 0 G film and S i 0 2 film, the lower electrode The surface of the upper electrode 22 together with the surface of 18b is always covered with the smoothing insulating film 24 and is not exposed by etching.
- an insulating film 26 is deposited on the entire surface of the substrate including the dummy electrode 18c and the smoothing insulating film 24 by using, for example, a plasma CVD method.
- the smoothing insulating film 24 and the insulating film 26 form an interlayer insulating film 27.
- the interlayer insulating film 27 on the upper electrode 22 and the lower electrode 18b is selectively removed by etching using a photolithography process and a dry etching method, so that the first and second vias are formed. ⁇ Open holes 28a and 28c, respectively.
- First First and second upper wiring layers 3 made of an A1 alloy layer connected to the periphery of the upper electrode 22 and the lower electrode 18b through the second and second via holes 28a and 28c, respectively. 0a and 30c are formed.
- the upper wiring layers (not shown) of other elements of the LSI are formed.
- a step having a thickness of about 100 to 500 nm is formed around the region where the capacitor element is to be formed on the semiconductor substrate 10 via the first insulating film 12.
- a TiN / A 1 —S layer is formed on the entire surface of the substrate including the polysilicon layer 34 through a second insulating film 16.
- i ZT i / T i ON / ⁇ i Multi-layer film 18 is formed and patterned into a predetermined shape, and Ti N / A l-S i / T i / T i ON / A lower electrode 18b of T i is formed, and the surrounding polysilicon is formed.
- T i N having a surface above the surface of the lower electrode 18b above the dummy layer 34
- the dummy electrode 18 c of ZT i ON / Ti is formed, and the upper electrode 22 is formed on the lower electrode 18 b via the dielectric film 20.
- an SiO 2 film is deposited on the entire surface of the substrate.
- a smoothing insulation for smoothing the entire surface of the substrate by filling the hollow surrounded by the dummy electrode 18c.
- T is the lower electrode 18a, 18b of the capacitive element and is the second upper layer via the second via hole 28b, 28c.
- the case where wiring is connected to wiring layers 30b and 30c is described, but the case where the lower electrodes 18a and 18b are used as wiring layers as they are and are connected to other elements in the LSI. There is also.
- the first and second upper wiring layers 30a, 30b, and 30c are formed by using a CVD method instead of depositing and processing an A1 alloy layer.
- etch back to form W plugs for filling the first and second via holes 28a, 28b, 28c, respectively.
- the A1 alloy layer is processed to form the first and second via holes 28a, 2a.
- a method of forming first and second upper wiring layers connected to the W plugs in 8b and 28c, respectively, may be used.
- FIG. 20 is a schematic cross-sectional view showing a capacitive element according to the fourth embodiment of the present invention.
- FIGS. 21 to 28 are each for explaining a method of manufacturing the capacitive element shown in FIG. 20.
- FIG. 21 to 28 are each for explaining a method of manufacturing the capacitive element shown in FIG. 20.
- a first insulating film 12 made of, for example, a SiO 2 film is provided on the periphery of the capacitance element formation region on the semiconductor substrate 10.
- a dummy polysilicon layer 14 for a step formed of a polysilicon (PolySi 1 icon) layer having a required thickness, for example, a thickness of about 100 to 500 nm is formed.
- the first insulating film 12 and the polysilicon —On the layer 14, a second insulating film 16 is formed. Note that the second insulating film 16 can be omitted.
- this second insulating film 16 for example, a Ti layer having a thickness of about 5 to 70 nm, a Ti 0 N layer having a thickness of about 10 to 20 nm, and a thickness of 5 to 7 nm
- a Ti layer with a thickness of about 0 nm, an A1-Si layer with a thickness of about 300 to 150 nm, and a TiN layer with a thickness of about 5 to 70 nm deposited in order from the bottom i N / A l — S i / T i / T i ON / T i laminated structure film, or lower electrode 18a of Cu, A 1 -Cu, etc. is formed.
- the lower electrode 18a of the TiNZAl-SiZTi / TiON / Ti stacked film is formed.
- the lower part of the polysilicon / dummy layer 14 for the step having a thickness of about 100 to 500 nm is more thicker than the surface of the central part.
- the surface of the peripheral portion is located at a position higher by, for example, about 100 to 500 nm.
- the uppermost T i N layer is an anti-reflection film in the photolithographic process during the manufacturing process and an anti-oxidation film of the A 1 — S i layer thereunder.
- the A 1 —S i layer functions as the main part of the electrode that requires conductive characteristics, and the underlying Ti / Ti 0 N / Ti laminated film functions as a non-metal.
- required thickness for example, a thickness of 1 0 ⁇ 3 0 O nm approximately T a 2 0 5, S i 0 2 or S i N dielectric film such as 2 0, via the dielectric film of T a 2 0 5 in the present example, the thickness of 5 ⁇ 1 0 0 nm approximately T i, T i N or T i and T i N upper electrode 2 composed of a laminated film of 2 is formed ...
- the dielectric film 2 0 T a 2 0 5 is a laminated film upper electrode 2 2 2 oxygen or react with difficulty had T i N a deposited in this order a T i N and T i It is preferable to form it.
- the upper The sub-electrode 22 can be formed of Ti, TiN or a laminated film of TiN and Ti.
- a capacitive element is formed by the upper electrode 22 and the lower electrode 18a sandwiching the dielectric film 20 therebetween.
- the surface of the dielectric film 20 formed on the central portion of the lower electrode 18a having the concave cross-sectional shape of the capacitive element is formed by the polysilicon of the lower electrode 18a having the concave cross-sectional shape.
- One layer 14 above the periphery. Its height is lower than the surface. .
- a smoothing process is performed on the irregularities on the surface of the S body composed of the upper electrode 22 and the lower electrode 18a. That is, for example, a smoothing insulating film 24 composed of a SiO 2 film deposited on the entire surface of the substrate and a S 0 G film coated thereon is formed using a plasma CVD method using TE 0 S as a raw material. The recess of the concave cross section of the lower electrode 18 a is filled with the smoothing insulating film 24. .
- an insulating film 2 6 consisting of S i 0 2 film is deposited.
- An interlayer insulating film 27 is formed by the smoothing insulating film 24 and the insulating film 26.
- a first upper wiring layer 30a made of one alloy layer is formed. Further, for example, an A1 alloy layer connected to the peripheral portion of the lower electrode 18a through a second via hole 28b opened in the interlayer insulating film 27 on the peripheral portion of the lower electrode 18a.
- a polysilicon layer is further formed on the first insulating film 12 to a required thickness, for example, 100 to 500 It is formed to a thickness of about nm. Subsequently, the polysilicon layer is selectively etched and removed by a photolithography process and an RIE process to pattern it into a predetermined shape.
- a polysilicon layer having a thickness of about 100 to 500 nm is formed around the semiconductor element 10 on the periphery of the area where the capacitor is to be formed with the first insulating film 12 interposed therebetween.
- a polysilicon / dummy layer 14 for a step is formed.
- the process of forming the polysilicon 'dummy layer 14 is performed by using other elements of the LSI, for example, a gate electrode (gate) electrode of a metal oxide semiconductor transistor (M0STr) or a resistor. It can also be used as a process for forming a resistive layer of an element and a polysilicon layer used as an electrode of a BipTr (Bipoar transistor).
- a gate electrode (gate) electrode of a metal oxide semiconductor transistor (M0STr) or a resistor can also be used as a process for forming a resistive layer of an element and a polysilicon layer used as an electrode of a BipTr (Bipoar transistor).
- a second insulating film 16 is formed on the entire surface of the substrate including the polysilicon dummy layer 14 for the step. Note that the formation of the second insulating film 16 can be omitted.
- a conductor film having a required thickness for example, Ti having a thickness of about 5 to 70 nm is formed on the second insulating film 16 by using, for example, a sputtering method.
- a TiN layer having a thickness of about 5 to 7 O nm is sequentially deposited from the bottom to form a TiN / Al-Si / Ti / TiON / Ti multilayer film 18.
- the uppermost T iN layer functions as an anti-reflection film in the photolithography process during the manufacturing process and as an anti-oxidation film for the A 1 -S i layer thereunder.
- a 1 — S i The layer functions as the main part of the electrode that needs to be conductive, and the underlying Ti
- the ZTi0N / Ti stacked film functions as a barrier metal.
- the surface above the polysilicon polysilicon dam layer 14 having a thickness of about 100 to 500 nm is the surface in the region surrounded by the polysilicon polysilicon layer 14. 1 0 0
- the CVD method is used to form Ta 2 0 5 , Ta 2 0 5 , on this Ti N / Al —Si ZTi i / Ti ON / Ti laminated film 18.
- S i 0 2, S i N but the present embodiment the T a 2 0 5 dielectric film required thickness, for example, you deposited to a thickness of about 1 0 ⁇ 3 0 0 nm.
- a conductor layer of, for example, a Ti layer, a TiN layer, or a laminated film of Ti and TiN is formed on this dielectric film to a required thickness, for example, 20 to Deposit to a thickness of about 500 nm.
- the conductive layer and the dielectric film thus laminated are selectively etched away and patterned into a predetermined shape.
- the thickness 10 to 3 is formed on the TiNZAl-SiZTi / TiONZTi laminated film 18 in the area surrounded by the polysilicon / dummy layer 14 for the step.
- Thickness 20 through dielectric film 20 of about 0 nm
- An upper electrode 22 composed of a Ti layer, a TiN layer or a laminated film of Ti and TiN of about 500 nm is formed.
- the surface of the upper electrode 22 is the same as or higher than the surface of the laminated film 18 above the dummy layer 14.
- the surface of the dielectric film 20 is lower than the surface of the laminated film 18 above the polysilicon / dummy layer 14.
- the photolithography process and In the RIE process the Ti i / A 1 -Si / Ti / Ti ON / Ti stacked film 18 is selectively etched away and patterned into a predetermined shape.
- the lower electrode 18a is formed of the TiN / A1-Si / Ti / Ti0N / Ti laminated film.
- a lower wiring layer (not shown) is formed by a TiNZAl-SiZTi / TiON / Ti stacked film of other elements of the LSI. .
- the surface of the dielectric film 20 of the capacitive element is lower in height than the surface of the peripheral portion of the lower electrode 18a above the polysilicon 'dummy layer 14.
- a smoothing process for smoothing irregularities on the entire surface of the substrate is performed. That is, for example, an SiO 2 film is applied to the entire surface of the substrate including the upper electrode 22 and the lower electrode 18 a by using the plasma CVD method using TE 0 S Deposit to a thickness of about 100 nm. Further, an SOG film is coated on the SiO 2 film. Thereafter, the S 0 G film and the S i O 2 film are etched back.
- a smoothing insulating film 24 for smoothing the entire surface of the substrate while filling the recesses of the concave cross section of the lower electrode 18a is formed.
- the surface of the dielectric film 20 formed on the central portion of the lower electrode 18a having the concave cross section is formed.
- the surface of the peripheral portion above the lower electrode 18 a of the lower electrode 18 a having a concave cross-sectional shape The height is lower than that.
- the etching rate of the S i 0 2 and T i and T i N does not change rather large, after the formation of the SOG film and S i 0 2 film E Tsu During the chipback, the surface of the periphery of the lower electrode 18a is exposed, but the surface of the dielectric film 20 is not exposed by etching. That is, the periphery of the lower electrode 18a becomes an etching stopper, and the dielectric film 20 below the upper electrode 22 is not damaged.
- an insulating film made of, for example, a SiO 2 film is formed on the entire substrate including the lower electrode 18 a and the smoothing insulating film 24 by using, for example, a plasma CVD method.
- Deposit film 26 deposit film 26.
- An interlayer insulating film 27 is formed by the smoothing insulating film 24 and the insulating film 26.
- the interlayer insulating film 27 on the upper electrode 22 is selectively removed by etching using a photolithography process and a dry etching method, and the interlayer insulating film on the peripheral portion of the lower electrode 18a. 27 is selectively removed by etching to open first and second via holes 28a and 28b, respectively. At this time, in order to reduce the contact resistance, only the TiN layer on the surface of the lower electrode 18a may be removed.
- the thickness of the interlayer insulating film 27 on the upper electrode 22 to be etched to open the first via hole 28 a opens the second via hole 28 b. Because the thickness of the interlayer insulating film 27 on the periphery of the lower electrode 18a to be etched is substantially equal to that of the first and second via holes 28a and 28b, At this time, the surface of the upper electrode 22 is not excessively over-etched.
- the upper wiring layers (not shown) of other elements of LSI are formed.
- a thickness of about 100 to 500 nm is provided around the semiconductor element 10 on the periphery of the capacitor element forming area through the first insulating film 12.
- Forming a polycrystalline silicon dummy layer 14 for a step composed of a polycrystalline silicon layer forming a second insulating film 16 on the entire surface of the substrate including the polycrystalline silicon dummy layer 14;
- On the second insulating film 16 there is formed a lower electrode 18 a having a concave cross section in which the surface of the peripheral portion above the polysilicon dummy layer 14 is higher than the surface of the central portion.
- a required thickness for example, a dielectric film 20 having a thickness of about 10 to 300 nm (that is, a dielectric film thinner than the dummy layer 14) 20 is formed on the central portion thereof, An upper electrode 22 having a thickness of, for example, about 5 to 100 nm is formed, and the height of the surface of the dielectric film 20 is reduced to a polysilicon layer of the lower electrode 18a.
- the interlayer insulation on the upper electrode 22 is etched to open the first via hole 28a. Since the film thickness of the film 27 is substantially equal to the film thickness of the interlayer insulating film 27 on the periphery of the lower electrode 18a to be etched to open the second via hole 28b, not Rukoto done excessive over one etching to the upper electrode 2 second surface, never upper electrode 2 2 and T a 2 0 5 dielectric film 2 0 thereunder damaged. Therefore, it is possible to further suppress the fluctuation of the characteristics such as the capacitance value of the capacitance element and the deterioration of the reliability, and to obtain the capacitance element having better characteristics and higher reliability.
- the depth of the second via hole 28 b opening on the lower electrode 18 a is higher than the upper electrode 22.
- the first via hole 28a is located at a position closer to the upper electrode 22 and the lower electrode 18a that effectively function as a capacitive element.
- the distance on the lower electrode side which generally tends to be longer than that on the upper electrode side, is shortened, so that the difference in impedance is reduced.
- an increase in the asymmetry of the characteristics of the capacitor can be suppressed. That is, the symmetry of the characteristics of the capacitance element can be improved.
- FIG. 29 is a schematic cross-sectional view showing a capacitive element according to the fifth embodiment of the present invention.
- FIGS. 30 and 31 are diagrams for explaining a method of manufacturing the capacitive element shown in FIG. It is a schematic process sectional drawing.
- the same reference numerals are given to the same components as those of the capacitive element shown in FIGS. 21 to 28 of the fourth embodiment, and description thereof will be omitted.
- no-dummy layer 14 for the step insulation by a required thickness of SIN, Sio, or the like is used.
- dummy layer for example, is characterized in that S i 0 2 dummy layer 3 2 for steps having a thickness of 1 0 0 ⁇ 5 0 0 nm approximately S i 0 layers are formed.
- Other components are the same as those in the above-described fourth embodiment.
- a first insulating film 12 made of, for example, a SiO 2 film on a semiconductor substrate 10
- an insulating film for example, a SiO film is formed to a thickness of about 100 to 500 nm. Subsequently, the SiO 2 film is selectively etched and removed by a photolithography process and an etching process to pattern it into a predetermined shape ′.
- the Si0 film having a thickness of about 100 to 50011 m is formed on the semiconductor substrate 10 in the peripheral portion of the region where the capacitor is to be formed, with the first insulating film 12 interposed therebetween. forming an S i 0 2 dummy layer 3 2.
- the second surface including the SiO 3 dummy layer 32 is An insulating film 16 is formed on the second insulating film 16, and a Ti N / A l -Si / Ti / Ti ONZT i laminated film 18 is formed on the second insulating film 16.
- a l — An upper electrode 22 is formed on the S i / T i / T i ON / T i laminated film 18 via a dielectric film 20, and a photolithography process and an RIE process are used to form the T i.
- N / A 1 ⁇ S i ZT i / T i ON / T i Multilayered film 18 is patterned to be above Si 0 2 dummy layer 3 above the surface of the center where upper electrode 22 is formed. Then, a lower electrode 18a having a concave cross-sectional shape in which the surface of the peripheral portion is high is formed. In this way, a capacitive element composed of the upper electrode 22 and the lower electrode 18a sandwiching the dielectric film 20 is formed.
- the dielectric film 2 0 of the surface of the capacitor element at this time its height from the surface of the peripheral portion of the S i 0 2 dummy layer 3 2 above the lower electrode 1 8 a is low.
- the surface of the dielectric film 20 formed on the central portion of the lower electrode 18a having the concave cross section is formed.
- the height of the lower electrode 18a having the concave cross-sectional shape is lower than the surface of the peripheral portion above the SiO 2 dummy layer 32.
- T i N Since the difference in etch rate between S i ⁇ 2 and T i, T i N is not large under general smoothing touchback conditions, even when etching back the S 0 G film and the S i 0 film, The periphery of the lower electrode 18a functions as an etching stopper, and the surface of the dielectric film 20 is not exposed by etching, even if the surface of the periphery of the lower electrode 18a is exposed. .
- an insulating film 26 made of, for example, a Si02 film is deposited on the entire surface of the base including the lower electrode 18a and the peripheral portion including the smoothing insulating film 24 to form the smoothing insulating film 24 and the insulating film 2. 6 to form an interlayer insulating film 27.
- the interlayer insulating film 27 on the upper electrode 22 is selectively removed by etching, and the interlayer insulating film 27 on the peripheral portion of the lower electrode 18a is selectively removed by etching.
- the second via holes 28a and 28b are opened. Bottom electrode 18 N Layers may be removed.
- the film thickness of the interlayer insulating film 27 on the upper electrode 22 to be etched to open the first via-hole 28 a is set to be such that the second via-hole 28 b is opened. Since the thickness of the interlayer insulating film 26 on the periphery of the lower electrode 18a to be etched is almost equal to that of the first and second via holes 28a and 28b, At this time, excessive overetching of the surface of the upper electrode 22 is not performed.
- a required thickness for example, 100 to 50, is provided on the semiconductor substrate 10 at the peripheral portion of the region where the capacitor element is to be formed via the first insulating film 12.
- the S i 0 2 a second insulating film 1 6 is formed on a substrate the entire surface including the dummy layer 3 2 of the second
- a lower electrode 18 a having a concave cross section in which the surface of the peripheral portion above the Si 0 2 dummy layer 32 is higher than the surface of the central portion is formed, and the central portion of the lower electrode 18 a is formed.
- An upper electrode 22 is formed thereon via a dielectric film 20, and the height of the surface of the dielectric film 20 is adjusted to the S i 0 2 thickness of the lower electrode 18 a.
- the height lower than the height of the lower electrode 18a when performing a smoothing process of depositing a SiO 2 film on the entire surface of the substrate, coating the S 0 G film, and then etching back the film.
- a Etsuchingusu door wrapper go-between dielectric film 2 0 by the etching will not be subject to no good time.
- the thickness of the interlayer insulating film 27 on the upper electrode 22 etched to open the first via ⁇ hole 28 a is Since the thickness of the interlayer insulating film 27 on the periphery of the lower electrode 18 a to be etched to open the via hole 28 b is almost equal to that of the lower electrode 18 a, excessive Etching is not performed, and the upper electrode 22 and the dielectric film 20 thereunder are not damaged. Accordingly, as in the case of the first embodiment, the variation in the characteristics such as the capacitance value of the capacitive element and the deterioration of the reliability are further suppressed, and the capacitive element having better characteristics and higher reliability is obtained. Can be obtained.
- the depth of the second via hole 28 b opening on the lower electrode 18 a is substantially equal to the depth of the first via hole 28 a opening on the upper electrode 22.
- the distance between the upper electrode 22 and the lower electrode 18a, which effectively function as a capacitive element, to the first and second upper wiring layers 30a and 30b is generally smaller than the distance between the upper electrode 22 and the lower electrode 18a. Since the distance on the lower electrode side, which tends to be longer, is reduced, the impedance is reduced as in the case of the first embodiment.
- a required thickness for example, a thickness of 100 to 100 ⁇ m, is formed on the semiconductor substrate 10 around the region where the capacitor is to be formed, via the first insulating film 12.
- 5 0 0 forms a S i 0 2 dummy layer 3 2 for nm order of the step, but instead of forming such S i 0 2 dummy more 3 2, the Photo Li lithography step and Etchingu step As a result, the central portion of the region where the capacitive element is to be formed on the semiconductor substrate 10
- the first insulating film 12 may be selectively etched away to form a recess having a depth of about 100 to 500 nm.
- a final dummy layer is formed by a combination of the selective etching of the first insulating film 12 and the dummy layer 32 (or the dummy layer 14, 'a dummy layer 34 described later). It is possible to form a depression with a depth of about 100 to 500 nm o
- the second embodiment of the second embodiment is formed on the first insulating film 12 in which a recess having a depth of about 100 to 500 nm is formed at the center of the area where the capacitor is to be formed.
- the second insulating film 16 is formed, and the TiN / Al—Si / Ti / TiON / Ti laminated film 1 is formed on the second insulating film 16. 8 and patterning the TiN / A1SiZTi / TiON / Ti laminated film 18 to form the upper portion of the recess formed in the first insulating film 12 It is possible to form the lower electrode 18a having a concave cross-sectional shape in which the surface of the peripheral portion is higher than the surface of the central portion. Therefore, the same operations and effects as those of the fifth embodiment can be obtained.
- FIG. 32 is a schematic cross-sectional view showing a capacitor according to a sixth embodiment of the present invention.
- FIGS. 33 to 38 are each for explaining a method of manufacturing the capacitor shown in FIG. 32.
- FIG. Here, the same reference numerals are given to the same components as those of the capacitance element shown in FIGS. 20 to 28 of the fourth embodiment, and description thereof will be omitted.
- a polysilicon for a step is provided around the capacitance element.
- a polysilicon layer for a step having the same thickness, for example, a thickness of about 100 to 500 nm ⁇
- the dummy layer 34 is formed around the capacitance element. There is a special feature in that it is formed in the surrounding area.
- a flat surface for example, a lower electrode 18 b of T i N / A 1 S i / T i / ⁇ i 0 ⁇ / ⁇ i is formed, and is separated from the lower electrode 18 b to surround the capacitive element.
- T i N / A 1 S i / T i / T i 0 N / T i having a surface higher than the surface of the upper electrode 22 above the polysilicon dummy layer 34 for the step
- the characteristic of this is that the electrode 18 c is formed.
- the other components are substantially the same as those in the fourth embodiment.
- a polysilicon layer is formed to a required thickness, for example, a thickness of about 100 to 500 nm. Subsequently, the polysilicon layer is selectively etched away by a photolithography step and a RIE step to pattern it into a predetermined shape.
- a polysilicon dummy layer 34 for a step formed of a polysilicon layer having a thickness of about 100 to 500 nm is formed.
- the process of forming the polysilicon 'dummy layer 34 is used as another element of the LSI, for example, a gate electrode of M0STr, a resistance layer of a resistance element, or an electrode of BipTr. It can also be used as a polysilicon layer forming process.
- FIG. 34 In the same manner as in the steps shown in FIGS. 2 to 24, a second insulating film 16 is formed on the entire surface of the substrate including the polysilicon dummy layer 34 for steps.
- the insulating film 16 can be omitted.
- a L-S i XT i / T i ON / T i laminated film 18 is formed, and T i N / A l -S i / T i / T i ON / T i laminated film 18 a 0 5 , S 10, S i N, etc.
- the upper electrode is made of T i, T i N or a laminated film of T i and T i N via the Ta 2 0 3 dielectric film 10.
- the surface of the dielectric film 20 is located above the polysilicon / dummy layer 3.4 of the TiN / A 1 -Si / Ti / TiON / Ti stacked film 18. Its height is lower than the top surface.
- the TiN / Al-Si / Ti / TiON / Ti stacked film 18 is selectively etched by a photolithography process and an RIE process. It is removed and buttered to a predetermined shape.
- the lower electrode 18 b of Ti N / A 1 S i / T i / T i ⁇ N / T i is formed in the region where the capacitor is to be formed on the second insulating film 16.
- a Ti having a top surface higher than the surface of the lower electrode 18b is provided above the polysilicon layer 34 around the area where the capacitor is to be formed.
- N / A 1 — S i / ⁇ i / T i 0 Dummy electrode 18 c is formed by N / T i.
- a lower wiring layer (not shown) is formed by a TiNZAl-Si / Ti / TiOSNZTi laminated film of other elements of LSI.
- a capacitive element composed of the upper electrode 22 and the lower L 8 b sandwiching the dielectric film 20 is formed.
- the surface of the dielectric film 20 of the capacitive element is lower than the uppermost surface of the dummy electrode 18c around the capacitive element forming region above the polysilicon layer ⁇ ⁇ ⁇ dummy layer 34. I'm sorry.
- a SiO 2 film is deposited on the entire surface of the substrate including the upper electrode 22 and the lower electrode 18 b to a thickness of about 300 to 150 nm. I do. Further, an SOG film is coated on the SiO 2 film. Thereafter, a smoothing process for etching back the SOG film and the SiO 2 film is performed. .
- the surface of the dielectric film 20 formed on the lower electrode 18b is damaged by the dielectric around the capacitor element forming region.
- the height of the electrode 18c is lower than the uppermost surface above the polysilicon-dummy layer 34.
- the etching rate difference between T i, d 1 and 3 i 0 2 is not large, so even when etching back the SOG film and S i 0 2 film, the surface of the dielectric film 20 is not affected. Is not exposed by etching.
- an insulating film 26 is deposited on the entire surface of the substrate including the dummy electrode 18c and the smoothing insulating film 24 by using, for example, a plasma CVD method.
- the smoothing insulating film 24 and the insulating film 26 form an interlayer insulating film 27.
- the interlayer insulating film 27 on the upper electrode 22 and the lower electrode 18b is selectively removed by etching using a photolithography process and a dry etching method, and the first and second vias are removed.
- the upper wiring layers (not shown) of other elements of the LSI are formed.
- a polysilicon layer for a step having a thickness of about 100 to 500 nm is formed through a first insulating film 12.
- a TiN / Al—SiZTi / TiON ⁇ i laminated film is formed on the entire surface of the substrate including the polysilicon / dummy layer 34 via a second insulating film 16.
- An upper electrode 22 is formed on the dielectric film 20 via a dielectric film 20, and the height of the surface of the dielectric film 20 is reduced to the uppermost surface above the polysilicon / dummy layer 34 of the electrode 18c.
- the dummy electrode 18 c is etched.
- the dielectric film 20 below the upper electrode 22 does not suffer damage due to etching. Therefore, similarly to the case of the fourth embodiment, it is possible to obtain a capacitance element having good characteristics and high reliability by suppressing fluctuations in characteristics such as the capacitance value of the capacitance element and deterioration in reliability. .
- the lower part of the capacitive element The electrodes 18a and 18b are connected to the second upper wiring layers 30b and 30c via the second via holes 28b and 28c, respectively.
- the lower electrodes 18a and 18b may also serve as wiring layers and be connected to other elements of the LSI.
- the first and second upper wiring layers 30a, 30b, and 30c are formed by using a W (tungsten) layer using a CVD method instead of depositing and processing an A1 alloy layer. After depositing, etch back to form W plugs to fill the first and second vias. Holes 28a, 28b, and 28c, respectively. After depositing the layers, the A1 alloy layer is processed using a photolithography process and a dry etching method to form first and second via holes 28a, 28b, 28 A method of forming first and second upper wiring layers respectively connected to the W plugs in c may be used.
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Description
Claims
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EP01945729.0A EP1233450B1 (en) | 2000-06-30 | 2001-06-29 | Semiconductor device and its manufacturing method |
JP2002507439A JP4997682B2 (ja) | 2000-06-30 | 2001-06-29 | 半導体装置及びその製造方法 |
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WO2018198330A1 (ja) * | 2017-04-28 | 2018-11-01 | ゼンテルジャパン株式会社 | キャパシタ装置とその製造方法 |
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JP3792589B2 (ja) * | 2001-03-29 | 2006-07-05 | 富士通株式会社 | 半導体装置の製造方法 |
KR100438789B1 (ko) * | 2002-09-19 | 2004-07-05 | 삼성전자주식회사 | 미세 선폭을 갖는 반도체 소자의 전극 배선 구조 및 그형성방법 |
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2001
- 2001-06-29 EP EP01945729.0A patent/EP1233450B1/en not_active Expired - Lifetime
- 2001-06-29 WO PCT/JP2001/005663 patent/WO2002003458A1/ja active Application Filing
- 2001-06-29 US US10/069,901 patent/US6770974B2/en not_active Expired - Lifetime
- 2001-06-29 KR KR1020027002768A patent/KR100814622B1/ko active IP Right Grant
- 2001-06-29 JP JP2002507439A patent/JP4997682B2/ja not_active Expired - Fee Related
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2012
- 2012-01-20 JP JP2012009778A patent/JP5477396B2/ja not_active Expired - Fee Related
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JPH0595048A (ja) * | 1991-10-02 | 1993-04-16 | Hitachi Ltd | 半導体集積回路装置の製造方法 |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10236890A1 (de) * | 2002-08-12 | 2004-03-04 | Infineon Technologies Ag | Integrierte Schaltungsanordnungen, insbesondere Kondensatoranordnungen, und zugehörige Herstellungsverfahren |
WO2018198330A1 (ja) * | 2017-04-28 | 2018-11-01 | ゼンテルジャパン株式会社 | キャパシタ装置とその製造方法 |
JPWO2018198330A1 (ja) * | 2017-04-28 | 2020-01-16 | ゼンテルジャパン株式会社 | キャパシタ装置とその製造方法 |
US11038012B2 (en) | 2017-04-28 | 2021-06-15 | AP Memory Technology Corp. | Capacitor device and manufacturing method therefor |
Also Published As
Publication number | Publication date |
---|---|
KR20020026005A (ko) | 2002-04-04 |
US20020180053A1 (en) | 2002-12-05 |
US6770974B2 (en) | 2004-08-03 |
EP1233450A1 (en) | 2002-08-21 |
EP1233450B1 (en) | 2014-08-27 |
JP5477396B2 (ja) | 2014-04-23 |
JP4997682B2 (ja) | 2012-08-08 |
KR100814622B1 (ko) | 2008-03-18 |
JP2012080132A (ja) | 2012-04-19 |
EP1233450A4 (en) | 2007-08-29 |
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