This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2021-0174208, filed on Dec. 7, 2021, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference.
The present disclosure relates to a semiconductor memory device, and in particular, to a three-dimensional semiconductor memory device with improved reliability and an increased integration density.
Higher integration of semiconductor devices may be required to satisfy consumer demand for superior performance and inexpensive prices. In the case of semiconductor devices, since integration may be a factor in determining product prices, increased integration may be of particular value. In the case of two-dimensional or planar semiconductor devices, since integration may be mainly determined by the area occupied by a unit memory cell, integration may be greatly influenced by the level of a fine pattern forming technology. However, expensive process equipment that may be needed to increase pattern fineness may set a practical limitation on increasing integration for two-dimensional or planar semiconductor devices. Thus, three-dimensional semiconductor memory devices including three-dimensionally arranged memory cells have been proposed.
Embodiments of the inventive concepts provide a semiconductor memory device with improved reliability and an increased integration density.
According to an embodiment of the inventive concept, a semiconductor memory device may include a cell array structure comprising first bonding pads, which are electrically connected to memory cells, and a peripheral circuit structure comprising second bonding pads, which are electrically connected to peripheral circuits and are bonded to the first bonding pads. The cell array structure may include a stack comprising horizontal conductive patterns stacked in a vertical direction, a vertical structure comprising vertical conductive patterns , which intersect the stack in the vertical direction, and a power capacitor in a planarization insulating layer on a portion of the stack.
According to an embodiment of the inventive concept, a semiconductor memory device may include a cell array structure comprising first bonding pads electrically connected to memory cells, and a peripheral circuit structure comprising second bonding pads, which are electrically connected to peripheral circuits and are bonded to the first bonding pads. The cell array structure may include a lower insulating layer having a first surface and a second surface, which are opposite to each other, a stack comprising horizontal conductive patterns , which are stacked on the first surface of the lower insulating layer, a vertical structure comprising vertical conductive patterns penetrating the stack, a power capacitor in a planarization insulating layer on the stack, an input/output plug penetrating the planarization insulating layer, and an input/output pad on the second surface of the lower insulating layer and electrically connected to the input/output plug. The power capacitor may be between the first bonding pads and the input/output pads, when viewed in a vertical section.
According to an embodiment of the inventive concept, a semiconductor memory device may include a cell array structure comprising first bonding pads electrically connected to memory cells and including a cell array region, and a first peripheral region that is adjacent the cell array region; and a peripheral circuit structure comprising second bonding pads electrically connected to peripheral circuits and are bonded to the first bonding pads. The peripheral circuit structure comprises a first core region that overlaps with the bit line connection region in a vertical direction, a second core region that overlaps with the word line connection region in a vertical direction, and a second peripheral region that overlaps with the first peripheral region in a vertical direction. The cell array structure may include a lower insulating layer having a first surface and a second surface, which are opposite to each other, a stack comprising word lines in the cell array region and stacked on the first surface of the lower insulating layer in a vertical direction, a vertical structure comprising bit lines in the cell array region and penetrating the stack, a planarization insulating layer in the cell array region and the first peripheral region and on the stack, and a power capacitor in the first peripheral region and in the planarization insulating layer. The power capacitor comprises a first metal pattern in an opening in the planarization insulating layer, a second metal pattern on the first metal pattern, and a dielectric material pattern between the first metal pattern and the second metal pattern. An input/output plug is provided in the first peripheral region and penetrates the planarization insulating layer, and an input/output pad is in the first peripheral region and on the second surface of the lower insulating layer and is electrically connected to the input/output plug.
Example embodiments of the inventive concepts will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown.
Referring to
The memory cell array 1 may include a plurality of memory cells MC, which are three-dimensionally arranged. Each of the memory cells MC may be provided between and electrically connected to a word line WL and a bit line BL, which are disposed to cross each other.
Each of the memory cells MC may include a selection element TR and a data storage element DS, which are electrically connected to each other in series. The selection element TR may be a field effect transistor (FET), and the data storage element DS may be realized with a capacitor, a variable resistor, or the like. As an example, the selection element TR may include a transistor whose gate electrode is electrically connected to the word line WL and whose drain/source terminals are electrically connected to the bit line BL and the data storage element DS, respectively.
The row decoder 2 may be configured to decode address information, which is input from the outside, and to select one of the word lines WL of the memory cell array 1, based on the decoded address information. The address information decoded by the row decoder 2 may be provided to a row driver (not shown), and in this case, the row driver may provide respective voltages to the selected one of the word lines WL and the unselected ones of the word lines WL, in response to the control of a control circuit.
The sensing amplifier 3 may be configured to sense, amplify, and output a difference in voltage between one of the bit lines BL, which is selected based on address information decoded by the column decoder 4, and a reference bit line.
The column decoder 4 may provide a data transmission path between the sensing amplifier 3 and an external device (e.g., a memory controller). The column decoder 4 may be configured to decode address information, which is input from the outside, and to select one of the bit lines BL, based on the decoded address information.
The control logic 5 may be configured to generate control signals, which are used to control data-writing or data-reading operations on the memory cell array 1.
Referring to
The cell array structure CS may include a memory cell array region CAR and a first peripheral region PR1. A memory cell array region CAR may include a bit line connection region BCR and a word line connection region WCR. The terms first, second, etc. may be used herein merely to distinguish one element from another.
The memory cell array 1 (e.g., see
The peripheral circuit structure PS may include a first core region CR1, a second core region CR2, and a second peripheral region PR2. The first and second core regions CR1 and CR2 may be vertically overlapped with the memory cell array region CAR. The second peripheral region PR2 may be vertically overlapped (e.g. overlapping in the vertical direction D3 described herein) with the first peripheral region PR1.
A plurality of sense amplifiers may be provided in the first core region CR1, and a plurality of sub-word line drivers may be provided in the second core region CR2.
A control signal generating circuit for controlling the sub-word line driver and a control signal generating circuit for controlling the sense amplifier may be provided in the first and second peripheral regions PR1 and PR2. In addition, voltage generators providing operation voltages to the sense amplifier and the sub-word line driver may be disposed in the first and second peripheral regions PR1 and PR2.
In an embodiment, a power capacitor (or a decoupling capacitor), which is used to filter noise between operating or operation powers to be input to the semiconductor memory device, may be provided in the first peripheral region PR1.
Referring to
In detail, the cell array structure CS may include the cell array region CAR and the first peripheral region PR1, and the cell array region CAR may include the bit line connection region BCR and the word line connection region WCR.
The cell array structure CS may include horizontal patterns (e.g., word lines), which are provided in the cell array region CAR and are sequentially stacked on a lower insulating layer 300, vertical patterns (e.g., bit lines), which are provided to vertically cross the horizontal patterns, and memory elements, which are interposed between the horizontal and vertical patterns.
In more detail, the cell array structure CS may include the lower insulating layer 300, which has first and second surfaces S1 and S2 that are opposite to each other, the word lines WL, the bit lines BL, a power capacitor PC, an input/output contact plug IOPLG, and first bonding pads BP1a, BP1b, and BP1c.
The lower insulating layer 300 may have the first surface S1 and the second surface S2, which are opposite to each other. A stack ST, in which interlayer insulating patterns ILD and the word lines WL are alternately stacked, may be disposed on the first surface S1 of the lower insulating layer 300.
The word lines WL may be parallel to the first surface S1 of the lower insulating layer 300, and the bit lines BL may extend in a third direction D3 (e.g., a vertical direction) perpendicular to the first surface S1 of the lower insulating layer 300. Meanwhile, in an embodiment, the word lines WL are described to be parallel to the first surface S1 of the lower insulating layer 300, but the inventive concept is not limited to this example. For example, the bit lines BL may be parallel to the first surface S1 of the lower insulating layer 300, and the word lines WL may extend in the third direction D3.
The word lines WL may extend from the bit line connection region BCR to the word line connection regions WCR, and the bit lines BL may be provided on the bit line connection region BCR. The word lines WL may include pad portions, which are provided on the word line connection region WCR and are connected to cell contact plugs CPLG. The word lines WL may be stacked on the word line connection region WCR to have a staircase structure. The pad portions of the word line WL may be located at different positions in horizontal and vertical directions. In an embodiment, some of the word lines WL, which are adjacent to the lower insulating layer 300, may be used as dummy word lines DE.
In an embodiment, each of the word lines WL may be provided to cross opposite surfaces of a semiconductor pattern SP or to have a double gate structure, as shown in
A planarization insulating layer 110 may be disposed in the word line connection region WCR and the first peripheral region PR1 and on the first surface S1 of the lower insulating layer 300. The planarization insulating layer 110 may cover a staircase structure of the stack ST. That is, the planarization insulating layer 110 may cover the pad portions of the word lines WL.
The power capacitor PC may be provided in the first peripheral region PR1 and in the planarization insulating layer 110. The power capacitor PC may constitute or otherwise provide a voltage generator which receives a power voltage input through an input/output pad IOPAD and outputs operation voltages for operating the memory cell array. In addition, the power capacitor PC may be configured to perform a filtering operation on noise between operating or operation powers, which are input through the input/output pad IOPAD.
In an embodiment, the power capacitor PC may be located between the input/output pads IOPAD and the first bonding pads BP1a, BP1b, and BP1c, when viewed in a vertical section (i.e., a cross-section taken along a vertical direction). The power capacitor PC may include a first metal pattern MP1, which is provided to conformally cover openings formed in the planarization insulating layer 110, second metal patterns MP2, which are respectively provided in the openings covered with the first metal pattern MP1, and a dielectric material pattern IP, which is provided between the first metal pattern MP1 and the second metal patterns MP2.
The first metal pattern MP1 of the power capacitor PC may be vertically spaced apart from the lower insulating layer 300. When measured in the third direction D3, a length (also referred to as a height along the vertical direction) of the first metal pattern MP1 may be smaller than a thickness of the stack ST.
The first metal pattern MP1 may be provided to have a uniform thickness, to cover side and bottom surfaces of the opening, and to have a cylindrical shape or a concave shape. In another embodiment, the first metal pattern MP1 may have a pillar shape extending in the third direction D3. In other embodiments, a portion of the first metal pattern MP1 may have a pillar shape, and another portion of the first metal pattern MP1 may have a concave shape; that is, the first metal pattern MP1 may have a hybrid structure.
The first and second metal patterns MP1 and MP2 of the power capacitor PC may be formed of or include at least one of doped semiconductor materials (e.g., doped silicon and doped germanium), conductive metal nitride materials (e.g., titanium nitride and tantalum nitride), metallic materials (e.g., tungsten, titanium, and tantalum), or metal-semiconductor compounds (e.g., tungsten silicide, cobalt silicide, and titanium silicide).
The power capacitor PC may be electrically connected to some of the first bonding pads BP1a, BP1b, and BP1c through contact plugs and conductive lines. In an embodiment, on a first interlayer insulating layer 120 covering the bit lines BL, the first metal pattern MP1 may be electrically connected to a contact plug (not shown).
The input/output contact plug IOPLG may be provided in the second peripheral region PR2 to penetrate the planarization insulating layer 110 and first and second interlayer insulating layers 120 and 130. The input/output contact plug IOPLG may be electrically connected to some of the first bonding pads BP1a, BP1b, and BP1c through contact plugs and conductive lines.
The first bonding pads BP1a, BP1b, and BP1c of the cell array structure CS may include first upper bonding pads BP1a provided in the bit line connection region BCR, second upper bonding pads BP1b provided in the word line connection regions WCR, and third upper bonding pads BP1c provided in the second peripheral region PR2.
The first upper bonding pads BP1a may be electrically connected to the bit lines BL through conductive lines and contact plugs, and the second upper bonding pads BP1b may be electrically connected to the cell contact plugs CPLG and the word lines WL through conductive lines and contact plugs. The third upper bonding pads BP1c may be electrically connected to the power capacitor PC and the input/output contact plug IOPLG through conductive lines and contact plugs.
In an embodiment, the input/output pads IOPAD and dummy pads DPAD may be disposed on the second surface S2 of the lower insulating layer 300.
In the second peripheral region PR2, the input/output pads IOPAD may be electrically connected to the input/output contact plug IOPLG through input/output vias BVA. The dummy pads DPAD may be provided on the bit line connection region BCR and the word line connection region WCR. The dummy pads DPAD may be electrically connected to dummy vias DVA. The dummy vias DVA may be surrounded by an insulating material and may be in an electrically-floated state, and the dummy pads DPAD and the dummy vias DVA may extend toward the cell array structure and may be used as a pathway for supplying hydrogen during the process of fabricating the semiconductor memory device. The input/output pads IOPAD and the dummy pads DPAD may be formed of or include the same metallic material (e.g., aluminum).
A protection layer 310 may be disposed on the second surface S2 of the lower insulating layer 300 to cover the input/output pads IOPAD and the dummy pads DPAD. The protection layer 310 may be a hydrogen-containing oxide layer. A hydrogen concentration in the protection layer 310 may be higher than a hydrogen concentration in the lower insulating layer 300. The protection layer 310 may be a high density plasma (HDP) oxide layer or a tetraethylortho silicate (TEOS) layer.
A capping insulating layer 320 and a passivation layer 330 may be sequentially formed on the protection layer 310. The capping insulating layer 320 and the passivation layer 330 may have a pad opening OP exposing a portion of the input/output pad IOPAD.
The capping insulating layer 320 may include, for example, a silicon nitride layer or a silicon oxynitride layer. The passivation layer 330 may be formed of or include at least one of polyimide-based materials (e.g., photo sensitive polyimide (PSPI)).
The peripheral circuit structure PS may include a semiconductor substrate 200, core and peripheral circuits SA, SWD, and PTR, which are provided on the semiconductor substrate 200, and second bonding pads BP2a, BP2b, and BP2c.
The peripheral circuit structure PS may include the first core region CR1, the second core region CR2, and the second peripheral region PR2.
A plurality of sense amplifiers SA may be provided on the first core region CR1 of the semiconductor substrate 200. A plurality of sub-word line drivers SWD may be provided on the second core region CR2 of the semiconductor substrate 200. Control circuits PTR may be provided on the second peripheral region PR2 of the semiconductor substrate 200.
Peripheral interlayer insulating layers 210 and 220 may be provided on a top surface of the semiconductor substrate 200. The peripheral interlayer insulating layers 210 and 220 may be provided on the semiconductor substrate 200 to cover the peripheral circuits SA, SWD, and PTR, peripheral contact plugs PCP, and peripheral circuit or peripheral conductive lines PLP. The peripheral contact plugs PCP and the peripheral conductive lines PLP may be electrically connected to the peripheral circuits SA, SWD, and PTR. Each of the peripheral interlayer insulating layers 210 and 220 may include a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and/or a low-k dielectric layer.
The second bonding pads BP2a, BP2b, and BP2c of the peripheral circuit structure PS may include first lower bonding pads BP2a provided in the first core region CR1, second lower bonding pads BP2b provided in the second core region CR2, and third lower bonding pads BP2c provided in the second peripheral region PR2.
The first lower bonding pads BP2a may be electrically connected to the sense amplifiers SA through peripheral conductive lines PLP and the peripheral contact plugs PCP. The second lower bonding pads BP2b may be electrically connected to the sub-word line drivers SWD through the peripheral conductive lines PLP and the peripheral contact plugs PCP. The third lower bonding pads BP2c may be electrically connected to the control circuits PTR through the peripheral conductive lines PLP and the peripheral contact plugs PCP.
In an embodiment, the first, second, and third lower bonding pads BP2a, BP2b, and BP2c may be directly connected to the first, second, and third upper bonding pads BP1a, BP1b, and BP1c, respectively. As used herein, when an element or layer is directly on or directly connected to another element or layer, no intervening elements or layers are present. The first, second, and third lower and upper bonding pads BP1a, BP1b, BP1c, BP2a, BP2b, and BP2c may be formed of or include the same metallic material and may have substantially the same size or area. The first, second, and third lower and upper bonding pads BP1a, BP1b, BP1c, BP2a, BP2b, and BP2c may be formed of or include at least one of, for example, copper (Cu), aluminum (Al), nickel (Ni), cobalt (Co), tungsten (W), titanium (Ti), tin (Sn), or alloys thereof.
Referring to
Each of the stacks ST may include the word lines WLa and WLb, which are provided on the lower insulating layer 300 and are stacked in the third direction D3 (i.e., a vertical direction), which is perpendicular to the first and second directions D1 and D2, with the interlayer insulating patterns ILD interposed therebetween.
The word lines WLa and WLb may be formed of or include at least one of doped semiconductor materials (e.g., doped silicon and doped germanium), conductive metal nitride materials (e.g., titanium nitride and tantalum nitride), metallic materials (e.g., tungsten, titanium, and tantalum), or metal-semiconductor compounds (e.g., tungsten silicide, cobalt silicide, and titanium silicide).
In an embodiment, each of the word lines WLa and WLb may be provided to face top and bottom surfaces of the semiconductor pattern SP or to have a double gate structure, as shown in
In an embodiment, the word lines WLa and WLb may include the first and second word lines WLa and WLb, which face each other in the second direction D2. Each of the first and second word lines WLa and WLb may include a line portion, which extends in the first direction D1 parallel to the first surface S1 of the lower insulating layer 300, and gate electrode portions, which extend from the line portion in the second direction D2 to have a protruding shape, as shown in
Each of the word lines WLa and WLb may have a pad portion PAD provided on the word line connection region WCR. The pad portions PAD of the word lines WLa and WLb may be stacked to form a staircase structure, and the planarization insulating layer 110 may be provided to cover the pad portions PAD. As a distance from the lower insulating layer 300 increases, a length of the word lines WLa and WLb in the first direction D1 may decrease.
The semiconductor patterns SP may be stacked in the third direction D3 and may be spaced apart from each other in the first and second directions D1 and D2. That is, the semiconductor patterns SP may be three-dimensionally arranged on the lower insulating layer 300. In the case where the word lines WL have the double gate structure, dummy insulating patterns DIP may be disposed between the semiconductor patterns SP, which are arranged in the first direction D1, and between a pair of sub-word lines.
The semiconductor patterns SP may be formed of or include at least one of silicon (Si), germanium (Ge), or silicon germanium (SiGe). As an example, the semiconductor patterns SP may be formed of or include single crystalline silicon. In an embodiment, the semiconductor patterns SP may have a band gap energy that is greater than that of silicon. For example, the semiconductor patterns SP may have a band gap energy of about 1.5 eV to 5.6 eV. When the semiconductor patterns SP have a band gap energy of about 2.0 eV to 4.0 eV, the semiconductor patterns SP may have optimal channel performance. As an example, the semiconductor patterns SP may be formed of or include at least one of oxide semiconductor materials (e.g., ZnxSnyO (ZTO), InxZnyO (IZO), ZnxO, InxGayZnzO (IGZO), InxGaySizO (IGSO), InxWyO (IWO), InxO, SnxO, TixO, ZnxONz, MgxZnyO, ZrxInyZnzO, HfxInyZnzO, SnxInyZnzO, AlxSnyInzZnaO, SixInyZnzO, AlxZnySnzO, GaxZnySnzO, ZrxZnySnzO, or combinations thereof).
Each of the semiconductor patterns SP may have a long axis parallel to the second direction D2 and may be a bar-shaped pattern, as shown in
A gate insulating layer Gox may be interposed between the channel regions CH of the semiconductor patterns SP and the word lines WLa and WLb. The gate insulating layers Gox may be formed of or include at least one of high-k dielectric materials, silicon oxide, silicon nitride, or silicon oxynitride and may have a single- or multi-layered structure. In an embodiment, the high-k dielectric materials may include at least one of hafnium oxide, hafnium silicon oxide, lanthanum oxide, zirconium oxide, zirconium silicon oxide, tantalum oxide, titanium oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, lithium oxide, aluminum oxide, lead scandium tantalum oxide, or lead zinc niobate.
First spacer insulating patterns SS1 may be respectively disposed between vertically adjacent ones of the interlayer insulating patterns ILD. The first spacer insulating patterns SS1 may be provided to surround the first source-drain region SD1 of the semiconductor pattern SP. A second spacer insulating pattern SS2 may be provided to surround the second source-drain region SD2 of the semiconductor pattern SP.
The first side surface of the semiconductor pattern SP may be in contact with the bit line BL, and the second side surface of the semiconductor pattern SP may be in contact with a storage electrode SE. Elements or layers that are described as “in contact” or “in contact with” other elements or layers may refer to physical contact.
Referring back to
The data storage element DS may be electrically connected to the second source-drain region SD2 of each semiconductor pattern SP. In an embodiment, the data storage element DS may be a capacitor, and the data storage element DS may include the storage electrode SE, the plate electrode PE, and a capacitor dielectric layer CIL therebetween.
The storage electrode SE may be electrically connected to the second source-drain region SD2 of each semiconductor pattern SP. Each of the storage electrodes SE may be provided at substantially the same level as a corresponding one of the semiconductor patterns SP. In other words, the storage electrodes SE may be stacked in the third direction D3 and may have a long axis parallel to the second direction D2. The storage electrodes SE may be respectively disposed between vertically adjacent ones of the interlayer insulating patterns ILD.
The capacitor dielectric layer CIL may be provided to conformally cover the storage electrodes SE. The plate electrode PE may be provided to fill inner spaces of the storage electrodes SE, which are covered with the capacitor dielectric layer CIL.
The first insulating isolation patterns STI1 may be respectively disposed between the bit lines BLa, which are adjacent to each other in the first direction D1. The first insulating isolation patterns STI1 may extend in the third direction D3.
The second insulating isolation patterns STI2 may be respectively disposed between the storage electrodes SE, which are adjacent to each other in the first direction D1. The second insulating isolation patterns STI2 may extend in the third direction D3.
Insulating gapfill patterns 105 may be provided on the lower insulating layer 300 and may extend in the first direction D1. The insulating gapfill patterns 105 may be provided to cover side surfaces of the bit lines BLa and BLb and side surfaces of the first insulating isolation patterns STI1. The insulating gapfill patterns 105 may be formed of or include at least one of silicon oxide, silicon oxynitride, or insulating materials, which are formed of using a spin-on-glass (SOG) technology.
Referring to
The first semiconductor layers 10 may be formed of or include at least one of, for example, silicon, germanium, silicon-germanium, or indium gallium zinc oxide (IGZO). In an embodiment, the first semiconductor layers 10 may be formed of or include the same semiconductor material as the lower insulating layer 300. For example, the first semiconductor layers 10 may be formed by an epitaxial growth method and may be a single crystalline silicon layer.
The second semiconductor layers 20 may be formed of or include at least one of, for example, silicon germanium, silicon oxide, silicon nitride, or silicon oxynitride. In an embodiment, the second semiconductor layers 20 may be formed by an epitaxial growth method and may be, for example, a silicon germanium layer. A thickness of the second semiconductor layers 20 may be substantially equal to or smaller than a thickness of the first semiconductor layers 10.
An upper insulating layer TL may be formed on the mold structure MS to cover the uppermost one of the second semiconductor layers 20. The upper insulating layer TL may be formed of or include an insulating material, which has an etch selectivity with respect to the first and second semiconductor layers 10 and 20. For example, the upper insulating layer TL may be a silicon oxide layer.
Referring to
Portions of the first semiconductor layers 10 may be left to form semiconductor patterns, and then, the word lines WL may be formed between the semiconductor patterns SP of
A patterning process may be performed on the mold structure, before the formation of the word lines WL, and in an embodiment, as a result of the patterning process, the mold structure MS may have a staircase structure in the word line connection region WCR. Next, the planarization insulating layer 110 may be formed to cover the staircase structure of the mold structure MS, and thereafter, a replacement process may be performed such that the word lines WL form a staircase structure in the word line connection region WCR.
After the formation of the word lines WL, the bit lines BL may be formed to extend in a direction perpendicular to a top surface of the first semiconductor substrate 100. Each of the bit lines BL may be in contact with side surfaces of the semiconductor patterns SP, as previously described with reference to
After the formation of the bit lines BL, the cell contact plugs CPLG may be formed to penetrate the planarization insulating layer 110 and to be connected to the word lines WL.
The first interlayer insulating layer 120 may be formed on the planarization insulating layer 110 to cover top surfaces of the bit lines BL.
Thereafter, the openings OP may be formed by patterning the first interlayer insulating layer 120 and a portion of the planarization insulating layer 110 in the first peripheral region PR1. The openings OP may extend in a direction that is perpendicular to the top surface of the first semiconductor substrate 100. Here, bottom surfaces of the openings OP may be spaced apart from the top surface of the first semiconductor substrate 100. In other words, an etching depth of the openings OP may be smaller than a thickness of the planarization insulating layer 110. The openings OP may have various shapes (e.g., rectangular, circular, or elliptical shapes), when viewed in a plan view. In addition, the openings OP may be arranged in a zigzag or honeycomb shape.
Referring to
The first metal layer ML1 may be formed of or include at least one of metallic materials (e.g., tungsten, titanium, and tantalum) and/or conductive metal nitrides (e.g., titanium nitride, tantalum nitride, and tungsten nitride).
The dielectric layer IL may be formed of at least one of metal oxides (e.g., HfO2, ZrO2, Al2O3, La2O3, Ta2O3, and TiO2) or perovskite dielectric materials (e.g., SrTiO3 (STO), (Ba,Sr)TiO3 (BST), BaTiO3, PZT, PLZT), and may have a single- or multi-layered structure.
After the formation of the dielectric layer IL, a second metal layer may be deposited to fill the openings, and a planarization process may be performed on the second metal layer. Accordingly, the second metal pattern MP2 may be formed in each opening. Here, second metal pattern MP2 may be formed of or include at least one of metallic materials (e.g., tungsten, titanium, and tantalum) or conductive metal nitride materials (e.g., titanium nitride, tantalum nitride, and tungsten nitride).
Next, a patterning process may be performed on the dielectric layer IL and the first metal layer ML1. That is, after the formation of the second metal patterns MP2, a mask pattern (not shown) may be formed on the second metal patterns MP2, and an anisotropic etching process using the mask pattern may be performed on the dielectric layer IL and the first metal layer ML1. Accordingly, as shown in
Thereafter, referring to
The input/output contact plug IOPLG may be formed in the first peripheral region PR1 to penetrate the first and second interlayer insulating layers 120 and 130 and the planarization insulating layer 110.
The formation of the input/output contact plug IOPLG may include forming a mask pattern (not shown) on the second interlayer insulating layer 130, forming a penetration hole exposing the first semiconductor substrate 100 by anisotropically etching the first and second interlayer insulating layers 120 and 130 and the planarization insulating layer 110 using the mask pattern as an etch mask, and filling the penetration hole with a conductive material.
Referring to
The uppermost interlayer insulating layer (e.g., 170) may be formed, and then, the first bonding pads BP1a, BP1b, and BP1c may be formed in the uppermost interlayer insulating layer (e.g., 170). The first bonding pads BP1a, BP1b, and BP1c may be formed using a damascene process.
Referring to
The first bonding pads BP1a, BP1b, and BP1c of the first semiconductor substrate 100 may be bonded to the second bonding pads BP2a, BP2b, and BP2c of the second semiconductor substrate 200.
The bonding process may be performed by performing a thermo-compression process, after placing the first bonding pads BP1a, BP1b, and BP1c to correspond to the second bonding pads BP2a, BP2b, and BP2c. As a result of the thermo-compression process, there may be no interface between the first bonding pads BP1a, BP1b, and BP1c and the second bonding pads BP2a, BP2b, and BP2c. Accordingly, the first bonding pads BP1a, BP1b, and BP1c may be bonded to the second bonding pads BP2a, BP2b, and BP2c, and the uppermost interlayer insulating layer 170 on the first semiconductor substrate 100 may be bonded to the uppermost peripheral interlayer insulating layer 220 on the second semiconductor substrate 200.
After the bonding between the first bonding pads BP1a, BP1b, and BP1c and the second bonding pads BP2a, BP2b, and BP2c, the first semiconductor substrate 100 may be removed. A grinding process, a planarization process, a wet etching process, and a dry etching process may be performed to remove the first semiconductor substrate 100.
As a result of the removal of the first semiconductor substrate 100, the input/output contact plug IOPLG and the planarization insulating layer 110 may be exposed to the outside, in the first peripheral region PR1. A portion (e.g., the lowermost interlayer insulating pattern ILD or the dummy word line DE) of the stack ST may be exposed to the outside, in the cell array region CAR.
Next, referring to
Thereafter, the input/output vias BVA and the dummy vias DVA may be formed in the lower insulating layer 300. The input/output vias BVA and the dummy vias DVA may be formed by forming via holes penetrating the lower insulating layer 300 and filling the via holes with a conductive material. The input/output vias BVA and the dummy vias DVA may be formed of or include at least one of tungsten (W), titanium (Ti), tantalum (Ta), or nitride materials thereof.
The input/output vias BVA may be electrically connected to the input/output contact plug IOPLG. The dummy vias DVA may be surrounded by an insulating material and may be in an electrically-floated state.
Thereafter, referring back to
After the formation of the input/output pad IOPAD and the dummy pads DPAD, a protection layer may be formed on the lower insulating layer 300, as shown in
The protection layer 310 may cover the input/output pad IOPAD and the dummy pads DPAD and may be formed of or include a hydrogen-containing insulating material. The protection layer 310 may be formed by a deposition process using oxygen and silane gases, and in an embodiment, hydrogen may remain in the protection layer 310 when the deposition process is performed. As an example, the protection layer 310 may be a hydrogen-containing high-density-plasma (HDP) oxide layer. A hydrogen concentration in the protection layer 310 may be higher than a hydrogen concentration in the lower insulating layer 300.
The protection layer 310 may be formed using, for example, a plasma-enhanced chemical vapor deposition (PECVD) method, a high density plasma (HDP) method, and/or a sputtering deposition method.
After the formation of the protection layer 310, a high-temperature thermal treatment process (or a hydrogen treatment process) may be performed. During the thermal treatment process, the hydrogen may be supplied to transistors in the cell array structure through the dummy pads DPAD and the dummy vias DVA. The thermal treatment process may be performed at a temperature of about 300° C. to 500° C. Accordingly, it may be possible to prevent a leakage current, which is caused by silicon defects (e.g., dangling bonds) in the cell array structure. Thus, it may be possible to improve electric characteristics of the semiconductor memory device.
Next, the capping insulating layer 320 and the passivation layer 330 may be sequentially formed on the protection layer 310. The capping insulating layer 320 may include a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer. The passivation layer 330 may be formed of or include at least one of polyimide-based materials (e.g., photo sensitive polyimide (PSPI)). The passivation layer 330 may be formed by a spin coating process.
Thereafter, the capping insulating layer 320 and the passivation layer 330 may be patterned to form the opening OP exposing a portion of the input/output pad IOPAD.
According to an embodiment of the inventive concept, bonding pads of a first substrate provided with memory cells may be bonded to bonding pads of a second substrate provided with peripheral circuits to connect a cell array structure to a peripheral circuit structure. Accordingly, an integration density of a semiconductor memory device may be increased. In addition, it may be possible to form a power capacitor in a portion of the cell array structure, without increasing a device area.
Furthermore, according to an embodiment of the inventive concept, input/output pads and dummy pads may be disposed near and extending toward the cell array structure and may be used as a pathway for supplying hydrogen to the cell array structure. Accordingly, when the semiconductor memory device is fabricated, electric characteristics of a memory cell array may be improved by a hydrogen treating process.
While example embodiments of the inventive concept have been particularly shown and described, it will be understood by one of ordinary skill in the art that variations in form and detail may be made therein without departing from the scope of the attached claims.
Number | Date | Country | Kind |
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10-2021-0174208 | Dec 2021 | KR | national |