摘要:
An integrated circuit is provided which includes a memory having multiple ports per memory cell for accessing a data bit within each of a plurality of the memory cells. Such memory includes an array of memory cells in which each memory cell includes a plurality of capacitors connected together as a unitary source of capacitance. A first access transistor is coupled between a first one of the plurality of capacitors and a first bitline and a second access transistor is coupled between a second one of the plurality of capacitors and a second bitline. In each memory cell, a gate of the first access transistor is connected to a first wordline and a gate of the second access transistor is connected to a second wordline.
摘要:
A method of forming a memory cell having a trench capacitor and a vertical transistor in a semiconductor substrate includes a step of providing a bonded semiconductor wafer having a lower substrate with an [010] axis parallel to a first wafer axis and an upper semiconductor layer having an [010] axis oriented at forty-five degrees with respect to the wafer axis, the two being connected by a layer of bonding insulator; etching a trench through the upper layer and lower substrate; enlarging the lower portion of the trench and converting the cross section of the upper portion of the trench from octagonal to rectangular, so that sensitivity to alignment errors between the trench lithography and the active area lithography is reduced. An alternative version employs a bonded semiconductor wafer having a lower substrate formed from a (111) crystal structure and the same upper portion. Applications include a vertical transistor that becomes insensitive to misalignment between the trench and the lithographic pattern for the active area, in particular a DRAM cell with a vertical transistor.
摘要:
A DRAM memory cell and process sequence for fabricating a dense (20 or 18 square) layout is fabricated with silicon-on-insulator (SOI) CMOS technology. Specifically, the present invention provides a dense, high-performance SRAM cell replacement that is compatible with existing SOI CMOS technologies. Various gain cell layouts are known in the art. The present invention improves on the state of the art by providing a dense layout that is fabricated with SOI CMOS. In general terms, the memory cell includes a first transistor provided with a gate, a source, and a drain respectively; a second transistor having a first gate, a second gate, a source, and a drain respectively; and a capacitor having a first terminal, wherein the first terminal of said capacitor and the second gate of said second transistor comprise a single entity.
摘要:
A vertical field effect transistor (“FET”) is provided which includes a transistor body region and source and drain regions disposed in a single-crystal semiconductor-on-insulator (“SOI”) region of a substrate adjacent a sidewall of a trench. The substrate includes a buried insulator layer underlying the SOI region and a bulk region underlying the buried insulator layer. A buried strap conductively connects the SOI region to a lower node disposed below the SOI region and a body contact extends from the transistor body region to the bulk region of the substrate, the body contact being insulated from the buried strap.
摘要:
A method of fabricating a vertical field effect transistor (“FET”) is provided which includes a transistor body region and source and drain regions disposed in a single-crystal semiconductor-on-insulator (“SOI”) region of a substrate adjacent a sidewall of a trench. The substrate includes a buried insulator layer underlying the SOI region and a bulk region underlying the buried insulator layer. A buried strap conductively connects the SOI region to a lower node disposed below the SOI region and a body contact extends from the transistor body region to the bulk region of the substrate, the body contact being insulated from the buried strap.
摘要:
A structure is provided herein which includes an array of trench capacitors having at least portions disposed below a buried oxide layer of an SOI substrate. Each trench capacitor shares a common unitary buried capacitor plate which includes at least a portion of a first unitary semiconductor region disposed below the buried oxide layer. An upper boundary of the buried capacitor plate defines a plane parallel to a major surface of the substrate which extends laterally throughout the array of trench capacitors. In a particular embodiment, which starts from either an SOI or a bulk substrate, trenches of the array and a contact hole are formed simultaneously, such that the contact hole extends to substantially the same depth as the trenches. The contact hole preferably has substantially greater width than the trenches such that the conductive contact via can be formed simultaneously by processing used to form trench capacitors extending along walls of the trenches.
摘要:
Trench type PIN photodetectors are formed by etching two sets of trenches simultaneously in a semiconductor substrate, the wide trenches having a width more than twice as great as the narrow trenches by a process margin; conformally filling both types of trenches with a sacrificial material doped with a first dopant and having a first thickness slightly greater than one half the width of the narrow trenches, so that the wide trenches have a remaining central aperture; stripping the sacrificial material from the wide trenches in an etch that removes a first thickness, thereby emptying the wide trenches; a) filling the wide trenches with a second sacrificial material of opposite polarity; or b) doping the wide trenches from the ambient such as by gas phase doping, plasma doping, ion implantation, liquid phase doping, infusion doping and plasma immersion ion implantation; diffusing the dopants into the substrate, forming p and n regions of the PIN diode; removing the first and the second sacrificial materials, and filling both the wide and the narrow sets of trenches with the same conductive material in contact with the diffused p and n regions.
摘要:
A structure and method are provided for forming a collar surrounding a portion of a trench in a semiconductor substrate, the collar having a lower edge self-aligned to a top edge of a buried plate disposed adjacent to a lower portion of the trench.
摘要:
A method of forming a memory cell having a trench capacitor and a vertical transistor in a semiconductor substrate includes a step of providing a bonded semiconductor wafer having a lower substrate with an [010] axis parallel to a first wafer axis and an upper semiconductor layer having an [010] axis oriented at forty-five degrees with respect to the wafer axis, the two being connected by a layer of bonding insulator; etching a trench through the upper layer and lower substrate; enlarging the lower portion of the trench and converting the cross section of the upper portion of the trench from octagonal to rectangular, so that sensitivity to alignment errors between the trench lithography and the active area lithography is reduced. An alternative version employs a bonded semiconductor wafer having a lower substrate formed from a (111) crystal structure and the same upper portion. Applications include a vertical transistor that becomes insensitive to misalignment between the trench and the lithographic pattern for the active area, in particular a DRAM cell with a vertical transistor.
摘要:
A structure and method are provided for forming a collar surrounding a portion of a trench in a semiconductor substrate, the collar having a lower edge self-aligned to a top edge of a buried plate disposed adjacent to a lower portion of the trench.