Abstract: Disclosed herein are 3D NAND memory devices having an oxide semiconductor vertical NAND channel and methods for forming the same. The oxide semiconductor may have a crystalline structure. The channel of the vertically-oriented NAND string may be cylindrically shaped. The crystalline structure has an axis that may be aligned crystalline with respect to the cylindrical shape of the vertically-oriented channel substantially throughout the vertically-oriented channel. The crystalline structure may have a first axis that is aligned parallel to the vertical channel, a second axis that is aligned perpendicular to a surface of the cylindrically shaped channel, etc.

Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings are formed through the alternating stack to the substrate. After formation of memory film layers, a sacrificial cover material layer can be employed to protect the tunneling dielectric layer during formation of a bottom opening in the memory film layers. An amorphous semiconductor material layer can be deposited and optionally annealed in an ambient including argon and/or deuterium to form a semiconductor channel layer having a thickness less than 5 nm and surface roughness less than 10% of the thickness. Alternately or additionally, at least one interfacial layer can be employed on either side of the amorphous semiconductor material layer to reduce surface roughness of the semiconductor channel. The ultrathin channel can have enhanced mobility due to quantum confinement effects.

Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. Memory openings are formed through the alternating stack to the substrate. After formation of memory film layers, a sacrificial cover material layer can be employed to protect the tunneling dielectric layer during formation of a bottom opening in the memory film layers. An amorphous semiconductor material layer can be deposited and optionally annealed in an ambient including argon and/or deuterium to form a semiconductor channel layer having a thickness less than 5 nm and surface roughness less than 10% of the thickness. Alternately or additionally, at least one interfacial layer can be employed on either side of the amorphous semiconductor material layer to reduce surface roughness of the semiconductor channel. The ultrathin channel can have enhanced mobility due to quantum confinement effects.

Abstract: Methods for improving channel boosting and reducing program disturb during programming of memory cells within a memory array are described. The memory array may comprise a NAND flash memory structure, such as a vertical NAND structure or a bit cost scalable (BiCS) NAND structure. In some cases, by applying continuous voltage ramping to unselected word lines during or throughout a programming operation, the boosting of channels associated with program inhibited memory cells may be improved. In one example, the slope and timing of a Vpass waveform applied to a group of unselected word lines (e.g.

Abstract: Methods for improving channel boosting and reducing program disturb during programming of memory cells within a memory array are described. The memory array may comprise a NAND flash memory structure, such as a vertical NAND structure or a bit cost scalable (BiCS) NAND structure. In some cases, by applying continuous voltage ramping to unselected word lines during or throughout a programming operation, the boosting of channels associated with program inhibited memory cells may be improved. In one example, the slope and timing of a Vpass waveform applied to a group of unselected word lines (e.g., the neighboring word lines of the selected word line) during the programming operation may be set based on the location of the selected word line within the memory array and the locations of the group of unselected word lines within the memory array.

Abstract: Peripheral devices for a three-dimensional memory device can be formed over an array of memory stack structures to increase areal efficiency of a semiconductor chip. First contact via structures and first metal lines are formed over an array of memory stack structures and an alternating stack of insulating layers and electrically conductive layers. A semiconductor material layer including a single crystalline semiconductor material or a polycrystalline semiconductor material is formed over first metal lines. After formation of semiconductor devices on or in the semiconductor material layer, metal interconnect structures including second metal lines and additional conductive via structures are formed to electrically connect nodes of the semiconductor devices to respective first metal lines and to memory devices underneath.

Abstract: A cylindrical confinement electron gas confined within a two-dimensional cylindrical region can be formed in a vertical semiconductor channel extending through a plurality of electrically conductive layers comprising control gate electrodes. A memory film in a memory opening is interposed between the vertical semiconductor channel and the electrically conductive layers. The vertical semiconductor channel includes a wider band gap semiconductor material and a narrow band gap semiconductor material. The cylindrical confinement electron gas is formed at an interface between the wider band gap semiconductor material and the narrow band gap semiconductor material. As a two-dimensional electron gas, the cylindrical confinement electron gas can provide high charge carrier mobility for the vertical semiconductor channel, which can be advantageously employed to provide higher performance for a three-dimensional memory device.

Abstract: A structure includes a three-dimensional semiconductor device including a plurality of unit device structures located over a substrate. Each of the unit device structures includes a semiconductor channel including at least a portion extending vertically along a direction perpendicular to a top surface of the substrate, and a drain region contacting a top end of the semiconductor channel. The structure also includes a combination of a plurality of contact pillars and a contiguous volume that laterally surrounds the plurality of contact pillars. The plurality of contact pillars is in contact with the drain regions, and the contiguous volume has a dielectric constant less than 3.9.

Abstract: A low-stress contact via structure for a device employing an alternating stack of insulating layers and electrically conductive layers over a substrate can be formed by forming a trench extending to the substrate through the alternating stack. After formation of an insulating spacer and a diffusion barrier layer, a remaining volume of the trench can be filled with a combination of an aluminum portion and a non-metallic material portion to form a contact via structure. The non-metallic material portion can include a semiconductor material portion or a dielectric material portion, and can prevent reflow of the aluminum portion and generation of a cavity in subsequent thermal processes. If a semiconductor material portion is employed, the aluminum portion and the semiconductor material portion can exchange places during a metal induced crystallization anneal process of the semiconductor material.

Abstract: Disclosed herein is 3D memory with vertical NAND strings having a III-V compound channel, as well as methods of fabrication. The III-V compound has at least one group III element and at least one group V element. The III-V compound provides for high electron mobility transistor cells. Note that III-V materials may have a much higher electron mobility compared to silicon. Thus, much higher cell current and overall cell performance can be achieved. Also, the memory device may have better read-write efficiency due to much higher carrier mobility and velocity. The tunnel dielectric of the memory cells may have an Al2O3 film in direct contact with the III-V NAND channel. The drain end of the NAND channel may be a metal-III-V alloy in direct contact with a metal region. The body of the source side select transistor could be formed from the III-V compound or from crystalline silicon.

Abstract: Disclosed herein is 3D memory with vertical NAND strings having a III-V compound channel, as well as methods of fabrication. The III-V compound has at least one group III element and at least one group V element. The III-V compound provides for high electron mobility transistor cells. Note that III-V materials may have a much higher electron mobility compared to silicon. Thus, much higher cell current and overall cell performance can be achieved. Also, the memory device may have better read-write efficiency due to much higher carrier mobility and velocity. The tunnel dielectric of the memory cells may have an Al2O3 film in direct contact with the III-V NAND channel. The drain end of the NAND channel may be a metal-III-V alloy in direct contact with a metal region. The body of the source side select transistor could be formed from the III-V compound or from crystalline silicon.

Abstract: A three dimensional memory device including a substrate and a semiconductor channel. At least one end portion of the semiconductor channel extends substantially perpendicular to a major surface of the substrate. The device also includes at least one charge storage region located adjacent to semiconductor channel and a plurality of control gate electrodes having a strip shape extending substantially parallel to the major surface of the substrate. The plurality of control gate electrodes include at least a first control gate electrode located in a first device level and a second control gate electrode located in a second device level located over the major surface of the substrate and below the first device level. Each of the plurality of control gate electrodes includes a first edge surface which is substantially free of silicide, the first edge surface facing the semiconductor channel and the at least one charge storage region and a silicide located on remaining surfaces of the control gate electrode.

Abstract: The band gap structure of a tunneling dielectric can be tailored to facilitate programming and erasing of stored information, while enhancing charge storage during states without electrical bias between a semiconductor channel and charge storage elements. The tunneling dielectric includes a layered stack including at least, from outside to inside, a dielectric metal oxide layer and a silicon oxide layer. Upon application of electrical bias for programming or erasing, the band gap structure of the tunneling dielectric provides a lower tunneling barrier than an ONO stack of a comparable effective oxide thickness. Additionally, due to higher capacitive coupling to the channel with high-k metal oxide layer(s) in the tunneling dielectric, the efficiency of program, erase and read operations can be improved. During a zero-bias state, the tunneling dielectric can provide a higher energy barrier than the ONO stack, thereby providing enhanced data retention than the ONO stack.

Abstract: A non-volatile storage device with memory cells having a high-k charge storage region, as well as methods of fabrication, is disclosed. The charge storage region has three or more layers of dielectric materials. At least one layer is a high-k material. The high-k layer(s) has a higher trap density as compared to Si3N4. High-k dielectrics in the charge storage region enhance capacitive coupling with the memory cell channel, which can improve memory cell current, program speed, and erase speed. The charge storage region has a high-low-high conduction band offset, which may improve data retention. The charge storage region has a low-high-low valence band offset, which may improve erase.

Abstract: Disclosed herein are techniques for fabricating 3D NAND memory devices having a mono-crystalline silicon semiconductor vertical NAND channel. Memory holes are formed in horizontal layers of material above a substrate. A vertically-oriented NAND string is formed in each of the memory holes. Forming the vertically-oriented NAND string channel comprises growing monolithic crystalline silicon upwards in the memory hole from the substrate through all of the plurality of horizontal layers of material. Vapor phase epitaxial growth may be used grow the monolithic crystalline silicon upwards from the bottom of the vertically-oriented NAND channel. Alternatively, a nanowire of monolithic crystalline silicon is synthesized in the memory hole from the substrate at the bottom of the vertically-oriented NAND channel upwards to the top of the vertically-oriented NAND channel.

Abstract: A 3D memory array having a vertically oriented thin film transistor (TFT) selection device that has a body formed from a wide energy band gap semiconductor is disclosed. The wide energy band gap semiconductor may be an oxide semiconductor, such as a metal oxide semiconductor. As examples, this could be an InGaZnO, InZnO, HfInZnO, or ZnInSnO body. The source and drains can also be formed from the wide energy band gap semiconductor, although these may be doped for better conduction. The vertically oriented TFT selection device serves as a vertical bit line selection device in the 3D memory array. A vertical TFT select device has a high drive current, a high breakdown voltage and low leakage current.

Abstract: A cylindrical confinement electron gas confined within a two-dimensional cylindrical region can be formed in a vertical semiconductor channel extending through a plurality of electrically conductive layers comprising control gate electrodes. A memory film in a memory opening is interposed between the vertical semiconductor channel and the electrically conductive layers. The vertical semiconductor channel includes a wider band gap semiconductor material and a narrow band gap semiconductor material. The cylindrical confinement electron gas is formed at an interface between the wider band gap semiconductor material and the narrow band gap semiconductor material. As a two-dimensional electron gas, the cylindrical confinement electron gas can provide high charge carrier mobility for the vertical semiconductor channel, which can be advantageously employed to provide higher performance for a three-dimensional memory device.

Abstract: Disclosed herein are thin film transistors (TFTs) and techniques for fabricating TFTs. A major plane of the gate electrode of the TFT may be vertically oriented with respect to a horizontal layer of polysilicon in which the TFT resides. An interface between the gate electrode and gate dielectric may be vertically oriented with respect to a horizontal layer of polysilicon in which the TFT resides. The TFT may have a channel width that is defined by a thickness of the horizontal layer of polysilicon. The TFT may be formed by etching a hole in a layer of polysilicon. Then, a gate electrode and gate dielectric may be formed in the hole by depositing layers of dielectric and conductor material on the sidewall. The body may be formed in the horizontal layer of polysilicon outside the hole.

Abstract: Disclosed herein are techniques for fabricating 3D NAND memory devices having a mono-crystalline silicon semiconductor vertical NAND channel. Memory holes are formed in horizontal layers of material above a substrate. A vertically-oriented NAND string is formed in each of the memory holes. Forming the vertically-oriented NAND string channel comprises growing monolithic crystalline silicon upwards in the memory hole from the substrate through all of the plurality of horizontal layers of material. Vapor phase epitaxial growth may be used grow the monolithic crystalline silicon upwards from the bottom of the vertically-oriented NAND channel. Alternatively, a nanowire of monolithic crystalline silicon is synthesized in the memory hole from the substrate at the bottom of the vertically-oriented NAND channel upwards to the top of the vertically-oriented NAND channel.

Abstract: A non-volatile storage device with memory cells having a high-k charge storage region, as well as methods of fabrication, is disclosed. The charge storage region has three or more layers of dielectric materials. At least one layer is a high-k material. The high-k layer(s) has a higher trap density as compared to Si3N4. High-k dielectrics in the charge storage region enhance capacitive coupling with the memory cell channel, which can improve memory cell current, program speed, and erase speed. The charge storage region has a high-low-high conduction band offset, which may improve data retention. The charge storage region has a low-high-low valence band offset, which may improve erase.