US20140131872A1 - Copper etching integration scheme - Google Patents
Copper etching integration scheme Download PDFInfo
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- US20140131872A1 US20140131872A1 US13/676,260 US201213676260A US2014131872A1 US 20140131872 A1 US20140131872 A1 US 20140131872A1 US 201213676260 A US201213676260 A US 201213676260A US 2014131872 A1 US2014131872 A1 US 2014131872A1
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- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76801—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
- H01L21/7682—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing the dielectric comprising air gaps
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- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
- H01L21/76877—Filling of holes, grooves or trenches, e.g. vias, with conductive material
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- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
- H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
- H01L21/76885—By forming conductive members before deposition of protective insulating material, e.g. pillars, studs
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- H01L23/53228—Conductive materials based on metals, e.g. alloys, metal silicides the principal metal being copper
- H01L23/53233—Copper alloys
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- H01L23/53238—Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
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- H01L23/522—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
- H01L23/532—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body characterised by the materials
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- H01L23/53257—Conductive materials based on metals, e.g. alloys, metal silicides the principal metal being a refractory metal
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Definitions
- RC delay time As the density of semiconductor devices increases and the size of circuit elements becomes smaller, the resistance capacitance (RC) delay time increasingly dominates the circuit performance. To reduce the RC delay, there is a desire to switch from conventional dielectrics to low-k dielectrics. These materials are particularly useful as intermetal dielectrics, IMDs, and as interlayer dielectrics, ILDs. However, low-k materials present problems during processing, especially during the processing of the conductive material used to make interconnects.
- FIGS. 1A-1M are partial cross sectional views illustrating steps of one embodiment of forming an interconnect structure in accordance with the disclosure.
- FIG. 2 illustrates a flow diagram of some embodiments of a method for the fabrication of an interconnect structure in accordance with the disclosure.
- transistor devices are manufactured or fabricated on semiconductor wafers using a number of different processing steps to create transistor and interconnection elements.
- conductive (e.g., metal) trenches, vias, and the like are formed in dielectric materials as part of the semiconductor device. The trenches and vias couple electrical signals and power between transistors, internal circuit of the semiconductor devices, and circuits external to the semiconductor device.
- the semiconductor wafer may undergo, for example, masking, etching, and deposition processes to form the desired electronic circuitry of the semiconductor devices.
- multiple masking and etching steps can be performed to form a pattern of recessed areas in a dielectric layer, such as a low-k dielectric layer, on a semiconductor wafer that serve as trenches and vias for the interconnections.
- a deposition process may then be performed to deposit a metal layer over the semiconductor wafer thereby depositing metal both in the trenches and vias and also on the non-recessed areas of the semiconductor wafer.
- the metal deposited on the non-recessed areas of the semiconductor wafer is removed.
- Low-k dielectric materials are susceptible to damage from the etching processes because they are softer, less chemically stable or more porous, or any combination of these factors.
- the plasma damage can manifest itself in higher leakage currents, lower breakdown voltages, and changes in the dielectric constant associated with the low-k dielectric material.
- the present disclosure is directed to methods of fabrication of an interconnect structure.
- the methods provide a process for defining an interconnect structure that eliminates low-k dielectric damage caused during etching processes.
- the process provides the further advantage of eliminating the necessity for etch stop or NFARC (nitrogen-free anti-reflective coating) layers, making the process more cost effective.
- NFARC nitrogen-free anti-reflective coating
- FIGS. 1A-1M illustrate a plurality of partial cross section diagrams illustrating one embodiment of a method of forming an interconnect structure at stages in the manufacturing process according to the disclosure.
- a semiconductor substrate 102 having a conductive region 103 is provided.
- Substrate 102 is understood to include a semiconductor wafer or substrate, comprised of a semiconducting material such as silicon or germanium, or a silicon on insulator structure (SOI).
- SOI silicon on insulator structure
- Semiconductor structure can further include one or more conductive layers (such as metal or silicon) and/or insulating layers, and one or more active or passive devices formed in or over the substrate, or the like, for example, a display substrate such as a liquid crystal display (LCD), plasma display, electro-luminescence (EL) lamp display, or a light emitting diode (LED) substrate.
- a display substrate such as a liquid crystal display (LCD), plasma display, electro-luminescence (EL) lamp display, or a light emitting diode (LED) substrate.
- Sacrificial layer 104 comprises a homopolymer or copolymer.
- sacrificial layer 104 comprises one or more of polyimide or P(neopentyl methacrylate-co-theylene glycol dimethacrylate copolymer (P(npMAco-EGDA).
- Sacrificial layer 104 is deposited by one or more of chemical vapor deposition (CVD) or spin-on coating processes. The thickness of the sacrificial layer will be in a range of from about 10000 ⁇ (angstroms) to about 100 ⁇ .
- a dielectric hard mask layer 108 is then deposited 106 by, for example, a CVD process, as illustrated in FIG. 1B .
- the dielectric hard mask layer 108 is used to pattern the sacrificial layer 104 in a subsequent photolithographic process.
- the dielectric hard mask layer 108 comprises a material such as silicon-oxide, silicon-nitride, silicon-oxynitride, and silicon-carbide.
- the dielectric hard mask layer 108 will have a thickness of from about 1000 ⁇ to about 10 ⁇ .
- a photoresist film 112 is formed by process 110 over the hard mask layer 108 , as illustrated in FIG. 1C .
- Conventional photoresist materials may be used.
- the photoresist film 112 can be a carbon-containing, organic material.
- Various photoresists having various thicknesses can be utilized.
- Photo resist patterning and etching 114 are performed in FIG. 1D .
- Hard mask 108 patterning and first etching process 116 through the hard mask layer 108 and into the sacrificial layer 104 are then performed to remove a portion of sacrificial layer 104 and form a first feature defined by an opening 118 in the sacrificial layer 104 , as shown in FIG. 1E .
- first feature comprises a trench.
- a metal layer 124 is deposited 122 over first feature and filling opening 118 in sacrificial layer 104 to form a metal body 125 therein.
- Metal body 125 is defined by a lower portion 124 ( a ) of the metal layer 124 .
- Metal body includes angled opposing sidewalls.
- the metal layer 124 can be formed from elements such as Al, W, Cu, CuMn, CuTi, CuCr or CuNb, and the like.
- Metal layer 124 can be formed using, for example, a plasma vapor deposition technique, among others.
- Metal layer 124 can be deposited at a thickness, in one embodiment, of from about 100 ⁇ (Angstroms) to about 20000 ⁇ .
- a photoresist film 112 ′ is formed over the metal layer 124 and patterned 126 by conventional techniques, as shown in FIG. 1G .
- a second etch 128 is performed to pattern and etch an upper portion 124 ( b ) of the metal layer 124 to form a second feature having first recesses 123 ( a ), 123 ( b ) and defined by a vertical projection 127 extending from the metal body 125 , as illustrated in FIG. 1H .
- Vertical projection 127 includes opposing sidewalls 129 ( a ), 129 ( b ) and upper surface 130 .
- second feature comprises a via.
- sacrificial layer 104 is removed by one or more of, for example, etching, wet stripping, annealing, UV or IR radiation techniques (not shown). Removal of the sacrificial layer 104 exposes angled opposing sidewalls 132 ( a ), 132 ( b ) of metal body 125 and forms second recesses 131 ( a ), 131 ( b ). Angled opposing sidewalls 132 ( a ), 132 ( b ) taper such that metal body 125 has a wider top 125 ( a ) and narrower bottom 125 ( b ).
- a barrier layer 134 is formed overlying and encompassing metal body 125 and vertical projection 127 and disposed between dielectric material 136 ( FIG. 1K ) and metal layer 124 . By encompassing metal body 125 and vertical projection 127 , barrier layer 134 is continuous. Barrier layer 134 is formed by depositing a dielectric material, for example, silicon-nitride and silicon-carbide. In one embodiment, barrier layer 134 is formed by depositing a metal, for example, TiN, TaN, Co, WN, TiSiN, TaSiN, or combinations thereof. In another embodiment, an annealing 135 is performed at a temperature of about greater than 200° C., such that barrier layer 134 is self-forming, as illustrated FIG. 1J . The thickness of the barrier layer 134 can be, in one embodiment, from about 1 ⁇ (Angstrom) to about 300 ⁇ .
- low-k dielectric material 136 is deposited by process 137 to fill first 123 ( a ), 123 ( b ) and second 131 ( a ), 131 ( b ) recesses and overlying the upper surface 130 of the vertical projection 127 to form a dielectric region 136 ′.
- Low-k dielectric material 136 thus encapsulates vertical projection 127 and metal body 125 .
- the low-k dielectric includes dielectrics with k less than about 3. Such dielectrics include, for example, carbon-doped silicon dioxide, also referred to as organosilicate glass (OSG) and carbon-oxide.
- Low-k materials may also include borophosphosilicate glass (BPSG), borosilicate glass (BSG), and phosphosilicate glass (PSG), among others.
- the dielectric layer 134 may be formed using, for example, tetraethyl orthosilicate (TEOS), chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), low pressure CVD (LPCVD), or spin-on coating techniques.
- TEOS tetraethyl orthosilicate
- CVD chemical vapor deposition
- PECVD plasma enhanced CVD
- LPCVD low pressure CVD
- the thickness of the low-k dielectric will be, in one embodiment, from about 100 ⁇ to about 20000 ⁇ .
- At least one air gap 138 is formed within the dielectric material 136 .
- the air gap 138 is disposed in the dielectric region 136 ′ between angled sidewalls 132 ( a ), 132 ( b ) of adjacent metal bodies 125 .
- Air gap 138 can be self-forming during deposition of the low-k material 136 .
- the size of the air gap can be from about 0 ⁇ to about 20000 ⁇ . It is contemplated, however, that the size of the air gap can be controlled by the low-k material 136 deposition process.
- a chemical mechanical polishing (CMP) process 138 can then be performed to remove excess dielectric layer 136 and expose upper surface 130 of vertical projection 127 , as illustrated in FIG. 1L .
- CMP chemical mechanical polishing
- the method can be repeated to form an additional metal layer 150 of an interconnect structure 152 overlying via and electrically coupled to the via, as illustrated in FIG. 1M , so as to form an integrated circuit 100 ′ of at least two adjacent interconnect structures.
- FIG. 2 illustrates a flow diagram of some embodiments of a method 200 for formation of a semiconductor structure according to an embodiment of the invention. While method 200 is illustrated and described below as a series of acts or events, it will be appreciated that the illustrated ordering of such acts or events are not to be interpreted in a limiting sense. For example, some acts may occur in different orders and/or concurrently with other acts or events apart from those illustrated and/or described herein. In addition, not all illustrated acts may be required to implement one or more aspects or embodiments of the description herein. Further, one or more of the acts depicted herein may be carried out in one or more separate acts and/or phases.
- a semiconductor substrate is provided.
- a sacrificial layer is then formed over the substrate at step 204 .
- a hard mask layer is deposited overlying the sacrificial layer.
- a first feature is formed by patterning and etching through hard mask and sacrificial layer to form an opening in the sacrificial layer.
- a metal layer is deposited overlying first feature and filling the feature opening.
- an upper portion of the metal layer is patterned and etched to form a second feature.
- sacrificial layer is removed.
- a barrier layer is formed by CVD, PVD, MOCVD or ALD, or barrier layer can be self-formed by annealing.
- a low-k dielectric material is deposited to fill recesses and encompass metal body and vertical projection.
- At step 220 at least one air gap is formed in the low-k dielectric material.
- the air gap is disposed in the dielectric region between adjacent interconnect structures.
- a CMP process is performed to remove excess dielectric layer and expose a top surface of the vertical projection. The method then ends.
- the disclosure relates to method for forming an interconnect structure comprising depositing a hard mask layer overlying the sacrificial layer.
- the method further comprises patterning the hard mask layer and the sacrificial layer to form a first feature defined by an opening in the sacrificial layer.
- the method further includes depositing a metal layer overlying the first feature and filling the opening to form a metal body therein, the metal body defined by a lower portion of the metal layer.
- the method further includes patterning and etching an upper portion of the metal layer to form a second feature having first recesses in an upper portion of the metal layer and defined by a vertical projection extending from the metal body.
- the method further includes removing the sacrificial layer to expose opposing sidewalls of the metal body and form second recesses about opposing sidewalls, and then depositing a low-k dielectric material overlying an upper surface of vertical projection and filling first and second recesses.
- the disclosure further relates to a method for forming a copper interconnect structure comprising providing a semiconductor substrate having a conductive region and forming a sacrificial layer overlying the substrate.
- the method further comprises forming a dielectric hard mask layer over the sacrificial layer.
- the method further comprises performing a first etching by etching the hard mask layer and the sacrificial layer to form a first feature opening in the sacrificial layer.
- the method further includes depositing forming a metal layer overlying the sacrificial layer and filling the feature opening.
- the method further includes performing a second etching by etching the metal layer to form a second feature and removing the sacrificial layer.
- the method further includes depositing a low-k dielectric material overlying the first and second features and forming at least one air gap within the low-k dielectric material.
- the disclosure further relates to an integrated circuit comprising at least two adjacent interconnect structures.
- the interconnect structures include a metal body having angled opposing sidewalls and a metal vertical projection extending from the metal body.
- the integrated circuit further comprises a low-k dielectric material is disposed overlying and between adjacent interconnect structures.
- the circuit further includes a barrier layer between the dielectric material and the interconnect structure.
Abstract
Description
- As the density of semiconductor devices increases and the size of circuit elements becomes smaller, the resistance capacitance (RC) delay time increasingly dominates the circuit performance. To reduce the RC delay, there is a desire to switch from conventional dielectrics to low-k dielectrics. These materials are particularly useful as intermetal dielectrics, IMDs, and as interlayer dielectrics, ILDs. However, low-k materials present problems during processing, especially during the processing of the conductive material used to make interconnects.
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FIGS. 1A-1M are partial cross sectional views illustrating steps of one embodiment of forming an interconnect structure in accordance with the disclosure. -
FIG. 2 illustrates a flow diagram of some embodiments of a method for the fabrication of an interconnect structure in accordance with the disclosure. - The description herein is made with reference to the drawings, wherein like reference numerals are generally utilized to refer to like elements throughout, and wherein the various structures are not necessarily drawn to scale. In the following description, for purposes of explanation, numerous specific details are set forth in order to facilitate understanding. It may be evident, however, to one of ordinary skill in the art, that one or more aspects described herein may be practiced with a lesser degree of these specific details. In other instances, known structures and devices are shown in block diagram form to facilitate understanding.
- Semiconductor devices are manufactured or fabricated on semiconductor wafers using a number of different processing steps to create transistor and interconnection elements. To electrically connect transistor terminals associated with the semiconductor wafer, conductive (e.g., metal) trenches, vias, and the like are formed in dielectric materials as part of the semiconductor device. The trenches and vias couple electrical signals and power between transistors, internal circuit of the semiconductor devices, and circuits external to the semiconductor device.
- In forming the interconnection elements the semiconductor wafer may undergo, for example, masking, etching, and deposition processes to form the desired electronic circuitry of the semiconductor devices. In particular, multiple masking and etching steps can be performed to form a pattern of recessed areas in a dielectric layer, such as a low-k dielectric layer, on a semiconductor wafer that serve as trenches and vias for the interconnections. A deposition process may then be performed to deposit a metal layer over the semiconductor wafer thereby depositing metal both in the trenches and vias and also on the non-recessed areas of the semiconductor wafer. To isolate the interconnections, such as patterned trenches and vias, the metal deposited on the non-recessed areas of the semiconductor wafer is removed.
- Increasingly, low-K layers are required to reduce signal delay and power loss effects as integrated circuit devices are scaled down. One way this has been accomplished has been to introduce porosity or dopants into the dielectric insulating layer.
- As a result, the need for lower dielectric constant materials has resulted in the development of several different types of organic and inorganic low-k materials. In particular, incorporation of low-K materials with dielectric constants less than about 3.0 has become standard practice as semiconductor feature sizes have diminished to less than 0.13 microns. As feature sizes decrease below 0.13 microns, for example to 65 nm and below, materials with dielectric constants less than about 2.5 are required. Several different organic and inorganic low-k materials have been developed and proposed for use in semiconductor devices as insulating material having dielectric constants between about 2.2 and about 3.0.
- Low-k dielectric materials, however, are susceptible to damage from the etching processes because they are softer, less chemically stable or more porous, or any combination of these factors. The plasma damage can manifest itself in higher leakage currents, lower breakdown voltages, and changes in the dielectric constant associated with the low-k dielectric material.
- There is, therefore, a need in the integrated circuit manufacturing art to develop a manufacturing process whereby interconnect structures may be formed without encountering the various problems presented by porous low-K dielectric layers to improve integrated circuit device yield, performance, and reliability.
- Accordingly, the present disclosure is directed to methods of fabrication of an interconnect structure. The methods provide a process for defining an interconnect structure that eliminates low-k dielectric damage caused during etching processes. The process provides the further advantage of eliminating the necessity for etch stop or NFARC (nitrogen-free anti-reflective coating) layers, making the process more cost effective.
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FIGS. 1A-1M illustrate a plurality of partial cross section diagrams illustrating one embodiment of a method of forming an interconnect structure at stages in the manufacturing process according to the disclosure. Referring toFIG. 1A , asemiconductor substrate 102 having aconductive region 103 is provided.Substrate 102 is understood to include a semiconductor wafer or substrate, comprised of a semiconducting material such as silicon or germanium, or a silicon on insulator structure (SOI). Semiconductor structure can further include one or more conductive layers (such as metal or silicon) and/or insulating layers, and one or more active or passive devices formed in or over the substrate, or the like, for example, a display substrate such as a liquid crystal display (LCD), plasma display, electro-luminescence (EL) lamp display, or a light emitting diode (LED) substrate. - Overlying
substrate 102 and coveringconductive region 103 is asacrificial layer 104.Sacrificial layer 104 comprises a homopolymer or copolymer. In one embodiment,sacrificial layer 104 comprises one or more of polyimide or P(neopentyl methacrylate-co-theylene glycol dimethacrylate copolymer (P(npMAco-EGDA).Sacrificial layer 104 is deposited by one or more of chemical vapor deposition (CVD) or spin-on coating processes. The thickness of the sacrificial layer will be in a range of from about 10000Å (angstroms) to about 100 Å. - A dielectric
hard mask layer 108 is then deposited 106 by, for example, a CVD process, as illustrated inFIG. 1B . The dielectrichard mask layer 108 is used to pattern thesacrificial layer 104 in a subsequent photolithographic process. In some embodiments, the dielectrichard mask layer 108 comprises a material such as silicon-oxide, silicon-nitride, silicon-oxynitride, and silicon-carbide. The dielectrichard mask layer 108 will have a thickness of from about 1000Å to about 10 Å. - Following deposition of the
hard mask layer 108, in one embodiment, aphotoresist film 112 is formed byprocess 110 over thehard mask layer 108, as illustrated inFIG. 1C . Conventional photoresist materials may be used. Thephotoresist film 112 can be a carbon-containing, organic material. Various photoresists having various thicknesses can be utilized. Photo resist patterning andetching 114 are performed inFIG. 1D . -
Hard mask 108 patterning andfirst etching process 116 through thehard mask layer 108 and into thesacrificial layer 104 are then performed to remove a portion ofsacrificial layer 104 and form a first feature defined by anopening 118 in thesacrificial layer 104, as shown inFIG. 1E . In one embodiment, first feature comprises a trench. - In
FIG. 1F , ametal layer 124 is deposited 122 over first feature and fillingopening 118 insacrificial layer 104 to form ametal body 125 therein.Metal body 125 is defined by a lower portion 124(a) of themetal layer 124. Metal body includes angled opposing sidewalls. In one embodiment, themetal layer 124 can be formed from elements such as Al, W, Cu, CuMn, CuTi, CuCr or CuNb, and the like.Metal layer 124 can be formed using, for example, a plasma vapor deposition technique, among others.Metal layer 124 can be deposited at a thickness, in one embodiment, of from about 100 Å (Angstroms) to about 20000 Å. - A
photoresist film 112′ is formed over themetal layer 124 and patterned 126 by conventional techniques, as shown inFIG. 1G . Asecond etch 128 is performed to pattern and etch an upper portion 124(b) of themetal layer 124 to form a second feature having first recesses 123(a), 123(b) and defined by avertical projection 127 extending from themetal body 125, as illustrated inFIG. 1H .Vertical projection 127 includes opposing sidewalls 129(a), 129(b) andupper surface 130. In one embodiment, second feature comprises a via. - In
FIG. 1I ,sacrificial layer 104 is removed by one or more of, for example, etching, wet stripping, annealing, UV or IR radiation techniques (not shown). Removal of thesacrificial layer 104 exposes angled opposing sidewalls 132(a), 132(b) ofmetal body 125 and forms second recesses 131(a), 131(b). Angled opposing sidewalls 132(a), 132(b) taper such thatmetal body 125 has a wider top 125(a) and narrower bottom 125(b). - In one embodiment, a
barrier layer 134 is formed overlying and encompassingmetal body 125 andvertical projection 127 and disposed between dielectric material 136 (FIG. 1K ) andmetal layer 124. By encompassingmetal body 125 andvertical projection 127,barrier layer 134 is continuous.Barrier layer 134 is formed by depositing a dielectric material, for example, silicon-nitride and silicon-carbide. In one embodiment,barrier layer 134 is formed by depositing a metal, for example, TiN, TaN, Co, WN, TiSiN, TaSiN, or combinations thereof. In another embodiment, anannealing 135 is performed at a temperature of about greater than 200° C., such thatbarrier layer 134 is self-forming, as illustratedFIG. 1J . The thickness of thebarrier layer 134 can be, in one embodiment, from about 1 Å (Angstrom) to about 300 Å. - In
FIG. 1K , low-k dielectric material 136 is deposited byprocess 137 to fill first 123(a), 123(b) and second 131(a), 131(b) recesses and overlying theupper surface 130 of thevertical projection 127 to form adielectric region 136′. Low-k dielectric material 136 thus encapsulatesvertical projection 127 andmetal body 125. The low-k dielectric includes dielectrics with k less than about 3. Such dielectrics include, for example, carbon-doped silicon dioxide, also referred to as organosilicate glass (OSG) and carbon-oxide. Low-k materials may also include borophosphosilicate glass (BPSG), borosilicate glass (BSG), and phosphosilicate glass (PSG), among others. Thedielectric layer 134 may be formed using, for example, tetraethyl orthosilicate (TEOS), chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), low pressure CVD (LPCVD), or spin-on coating techniques. The thickness of the low-k dielectric will be, in one embodiment, from about 100 Å to about 20000 Å. - In the embodiment illustrated in
FIG. 1K , at least oneair gap 138 is formed within thedielectric material 136. Theair gap 138 is disposed in thedielectric region 136′ between angled sidewalls 132(a), 132(b) ofadjacent metal bodies 125.Air gap 138 can be self-forming during deposition of the low-k material 136. In one embodiment, the size of the air gap can be from about 0 Å to about 20000 Å. It is contemplated, however, that the size of the air gap can be controlled by the low-k material 136 deposition process. A chemical mechanical polishing (CMP)process 138 can then be performed to remove excessdielectric layer 136 and exposeupper surface 130 ofvertical projection 127, as illustrated inFIG. 1L . - Following CMP process, the method can be repeated to form an
additional metal layer 150 of aninterconnect structure 152 overlying via and electrically coupled to the via, as illustrated inFIG. 1M , so as to form anintegrated circuit 100′ of at least two adjacent interconnect structures. -
FIG. 2 illustrates a flow diagram of some embodiments of amethod 200 for formation of a semiconductor structure according to an embodiment of the invention. Whilemethod 200 is illustrated and described below as a series of acts or events, it will be appreciated that the illustrated ordering of such acts or events are not to be interpreted in a limiting sense. For example, some acts may occur in different orders and/or concurrently with other acts or events apart from those illustrated and/or described herein. In addition, not all illustrated acts may be required to implement one or more aspects or embodiments of the description herein. Further, one or more of the acts depicted herein may be carried out in one or more separate acts and/or phases. - At step 202 a semiconductor substrate is provided. A sacrificial layer is then formed over the substrate at
step 204. - At
step 206, a hard mask layer is deposited overlying the sacrificial layer. - At
step 208, a first feature is formed by patterning and etching through hard mask and sacrificial layer to form an opening in the sacrificial layer. - At
step 210, a metal layer is deposited overlying first feature and filling the feature opening. - At
step 212, an upper portion of the metal layer is patterned and etched to form a second feature. - At
step 214, sacrificial layer is removed. - At
step 216, a barrier layer is formed by CVD, PVD, MOCVD or ALD, or barrier layer can be self-formed by annealing. - At
step 218, a low-k dielectric material is deposited to fill recesses and encompass metal body and vertical projection. - At
step 220, at least one air gap is formed in the low-k dielectric material. The air gap is disposed in the dielectric region between adjacent interconnect structures. - At
step 222, a CMP process is performed to remove excess dielectric layer and expose a top surface of the vertical projection. The method then ends. - It will be appreciated that equivalent alterations and/or modifications may occur to one of ordinary skill in the art based upon a reading and/or understanding of the specification and annexed drawings. The disclosure herein includes all such modifications and alterations and is generally not intended to be limited thereby. In addition, while a particular feature or aspect may have been disclosed with respect to only one of several implementations, such feature or aspect may be combined with one or more other features and/or aspects of other implementations as may be desired. Furthermore, to the extent that the terms “includes”, “having”, “has”, “with”, and/or variants thereof are used herein, such terms are intended to be inclusive in meaning—like “comprising.” Also, “exemplary” is merely meant to mean an example, rather than the best. It is also to be appreciated that features, layers and/or elements depicted herein are illustrated with particular dimensions and/or orientations relative to one another for purposes of simplicity and ease of understanding, and that the actual dimensions and/or orientations may differ substantially from that illustrated herein.
- Therefore, the disclosure relates to method for forming an interconnect structure comprising depositing a hard mask layer overlying the sacrificial layer. The method further comprises patterning the hard mask layer and the sacrificial layer to form a first feature defined by an opening in the sacrificial layer. The method further includes depositing a metal layer overlying the first feature and filling the opening to form a metal body therein, the metal body defined by a lower portion of the metal layer. The method further includes patterning and etching an upper portion of the metal layer to form a second feature having first recesses in an upper portion of the metal layer and defined by a vertical projection extending from the metal body. The method further includes removing the sacrificial layer to expose opposing sidewalls of the metal body and form second recesses about opposing sidewalls, and then depositing a low-k dielectric material overlying an upper surface of vertical projection and filling first and second recesses.
- The disclosure further relates to a method for forming a copper interconnect structure comprising providing a semiconductor substrate having a conductive region and forming a sacrificial layer overlying the substrate. The method further comprises forming a dielectric hard mask layer over the sacrificial layer. The method further comprises performing a first etching by etching the hard mask layer and the sacrificial layer to form a first feature opening in the sacrificial layer. The method further includes depositing forming a metal layer overlying the sacrificial layer and filling the feature opening. The method further includes performing a second etching by etching the metal layer to form a second feature and removing the sacrificial layer. The method further includes depositing a low-k dielectric material overlying the first and second features and forming at least one air gap within the low-k dielectric material.
- The disclosure further relates to an integrated circuit comprising at least two adjacent interconnect structures. The interconnect structures include a metal body having angled opposing sidewalls and a metal vertical projection extending from the metal body. The integrated circuit further comprises a low-k dielectric material is disposed overlying and between adjacent interconnect structures. The circuit further includes a barrier layer between the dielectric material and the interconnect structure.
Claims (19)
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CN201310047513.3A CN103811414B (en) | 2012-11-14 | 2013-02-06 | Copper etching integrated approach |
US14/218,060 US9373586B2 (en) | 2012-11-14 | 2014-03-18 | Copper etching integration scheme |
US15/153,967 US9633949B2 (en) | 2012-11-14 | 2016-05-13 | Copper etching integration scheme |
US15/463,617 US10020259B2 (en) | 2012-11-14 | 2017-03-20 | Copper etching integration scheme |
US16/017,039 US10354954B2 (en) | 2012-11-14 | 2018-06-25 | Copper etching integration scheme |
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US20170213786A1 (en) * | 2016-01-27 | 2017-07-27 | Samsung Electronics Co., Ltd. | Semiconductor device and method of manufacturing the same |
US10121660B2 (en) | 2016-08-18 | 2018-11-06 | Samsung Electronics Co., Ltd. | Method for fabricating semiconductor device |
WO2023024344A1 (en) * | 2021-08-25 | 2023-03-02 | 长鑫存储技术有限公司 | Method for forming semiconductor structure, and semiconductor structure |
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US9373586B2 (en) * | 2012-11-14 | 2016-06-21 | Taiwan Semiconductor Manufacturing Co., Ltd. | Copper etching integration scheme |
KR102420087B1 (en) | 2015-07-31 | 2022-07-12 | 삼성전자주식회사 | Method of fabricating a semiconductor device |
US9786760B1 (en) * | 2016-09-29 | 2017-10-10 | International Business Machines Corporation | Air gap and air spacer pinch off |
US10029908B1 (en) * | 2016-12-30 | 2018-07-24 | Texas Instruments Incorporated | Dielectric cladding of microelectromechanical systems (MEMS) elements for improved reliability |
CN108550564A (en) * | 2018-06-12 | 2018-09-18 | 长江存储科技有限责任公司 | Form method, conductive interconnecting structure and the three-dimensional storage of conductive interconnecting structure |
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US6686273B2 (en) * | 2001-09-26 | 2004-02-03 | Sharp Laboratories Of America, Inc. | Method of fabricating copper interconnects with very low-k inter-level insulator |
US20030134495A1 (en) * | 2002-01-15 | 2003-07-17 | International Business Machines Corporation | Integration scheme for advanced BEOL metallization including low-k cap layer and method thereof |
JP5180426B2 (en) * | 2005-03-11 | 2013-04-10 | ルネサスエレクトロニクス株式会社 | Manufacturing method of semiconductor device |
KR100829603B1 (en) * | 2006-11-23 | 2008-05-14 | 삼성전자주식회사 | Method of manufacturing a semiconductor device having an air-gap |
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US20170213786A1 (en) * | 2016-01-27 | 2017-07-27 | Samsung Electronics Co., Ltd. | Semiconductor device and method of manufacturing the same |
US10867923B2 (en) | 2016-01-27 | 2020-12-15 | Samsung Electronics Co., Ltd. | Semiconductor device |
US10121660B2 (en) | 2016-08-18 | 2018-11-06 | Samsung Electronics Co., Ltd. | Method for fabricating semiconductor device |
WO2023024344A1 (en) * | 2021-08-25 | 2023-03-02 | 长鑫存储技术有限公司 | Method for forming semiconductor structure, and semiconductor structure |
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