摘要:
Disclosed is a semiconductor device having an internal circuit protected by an electrostatic protective circuit, the internal circuit and electrostatic protective circuit being formed on the same semiconductor substrate. The internal circuit includes MIS elements and has a double-diffused drain structure, while the protective circuit has a single-diffused drain structure. The internal circuit can be, e.g., a DRAM, and the protective circuit can have diffused resistors and clamping MIS elements. The single-diffused drain structure can be formed in the protective circuit on the semiconductor substrate, while providing double-diffused drain structure in the internal circuit on the same substrate, by: (1) scanning the ion implanting apparatus to avoid ion implantation of the first ions into the region of the protective circuit, and/or (2) forming a photoresist film over the region of the protective circuit to prevent ion implanation of the first ions into the protective circuit region. As a further embodiment of the present invention, a semiconductor integrated circuit device is provided wherein the source and drain regions of an MOSFET in the internal circuit have lightly doped drain (LDD) structure in order to suppress the appearance of hot carriers, and the source and drain regions of an MOSFET in the input/output circuit have structure doped with phosphorus at a high impurity concentration, in order to enhance an electrostatic breakdown voltage.
摘要:
A semiconductor memory device wherein a portion of source region of a field-effect transistor that serves as a memory cell has a low impurity concentration, so that hot carriers generated on the source side are injected into the floating gate. Hot carriers are generated by utilizing a large electric field intensity established by the drop of voltage in the region of low impurity concentration. The voltage difference is so great between the source region and the control gate that hot carriers generated on the source side are efficiently injected into the floating gate.
摘要:
Disclosed are memory cells of a vertical-type read only memory (ROM) having a plurality of MISFETs connected in series. The MISFETs include gate electrodes formed with multiple conductive layers, in which some of the MISFETs are set to the depletion type and at least some of the remaining MISFETs are set to the enhancement type, so as to write information in the memory cells. The information write operation is conducted through at least two steps. Namely, in the first information write step, gate electrodes are used as a mask to implant an impurity; and in the second step, an impurity is implanted through the gate electrodes into the surface of the semiconductor substrate. These steps enable a semiconductor memory device, such as a vertical-type mask ROM having memory cells with a reduced series resistance and being suitable for a high degree of integration, to be produced.Furthermore, there is disclosed a memory structure of a semiconductor memory device suitable for a higher degree of integration through an arrangement of gate electrodes of multiple layers.
摘要:
A semiconductor integrated circuit device wherein the source and drain regions of a MOSFET in an internal circuit have lightly doped drain (LDD) structures in order to suppress the appearance of hot carriers, and the source and drain regions of a MOSFET in an input/output circuit have structures doped with phosphorus at a high impurity concentration, in order to enhance an electrostatic breakdown voltage.
摘要:
Disclosed is a semiconductor device having an internal circuit protected by an electrostatic protective circuit, the internal circuit and electrostatic protective circuit being formed on the same semiconductor substrate. The internal circuit includes MIS elements and has a double-diffused drain structure, while the protective circuit has a single-diffused drain structure. The internal circuit can be, e.g., a DRAM, and the protective circuit can have diffused resistors and clamping MIS elements. The single-diffused drain structure can be formed in the protective circuit on the semiconductor substrate, while providing double-diffused drain structure in the internal circuit on the same substrate, by: (1) scanning the ion implanting apparatus to avoid ion implantation of the first ions into the region of the protective circuit, and/or (2) forming a photoresist film over the region of the protective circuit to prevent ion implanation of the first ions into the protective circuit region. As a further embodiment of the present invention, a semiconductor integrated circuit device is provided wherein the source and drain regions of an MOSFET in the internal circuit have lightly doped drain (LDD) structure in order to suppress the appearance of hot carriers, and the source and drain regions of an MOSFET in the input/output circuit have structure doped with phosphorus at a high impurity concentration, in order to enhance an electrostatic breakdown voltage.
摘要:
Disclosed is a semiconductor device having an internal circuit protected by an electrostatoc protective circuit, the internal circuit and electrostatic protective circuit being formed on the same semiconductor substrate. The internal circuit includes MIS elements and has a double-diffused drain structure, while the protective circuit has a single-diffused drain structure. The internal circuit can be, e.g., a DRAM, and the protective circuit can have diffused resistors and clamping MIS elements. The single-diffused drain structure can be formed in the protective circuit on the semiconductor substrate, while providing double-diffused drain structure in the internal circuit on the same substrate, by: (1) scanning the ion implanting apparatus to avoid ion implantation of the first ions into the region of the protective circuit, and/or (2) forming a photoresist film over the region of the protective circuit to prevent ion implanation of the first ions into the protective circuit region. As a further embodiment of the present invention, a semiconductor integrated circuit device is provided wherein the source and drain regions of an MOSFET in the internal circuit have lightly doped drain (LDD) structure in order to suppress the appearance of hot carriers, and the source and drain regions of an MOSFET in the input/output circuit have structure doped with phosphorus at a high impurity concentration, in order to enhance an electrostatic breakdown voltage.
摘要:
Disclosed is a semiconductor device having an internal circuit protected by an electrostatic protective circuit, the internal circuit and electrostatic protective circuit being formed on the same semiconductor substrate. The internal circuit includes MIS elements and has a double-diffused drain structure, while the protective circuit has a single-diffused drain structure. The internal circuit can be, e.g., a DRAM, and the protective circuit can have diffused resistors and clamping MIS elements. The single-diffused drain structure can be formed in the protective circuit on the semiconductor substrate, while providing double-diffused drain structure in the internal circuit on the same substrate, by: (1) scanning the ion implanting apparatus to avoid ion implantation of the first ions into the region of the protective circuit, and/or (2) forming a photoresist film over the region of the protective circuit to prevent ion implanation of the first ions into the protective circuit region. As a further embodiment of the present invention, a semiconductor integrated circuit device is provided wherein the source and drain regions of an MOSFET in the internal circuit have lightly doped drain (LDD) structure in order to suppress the appearance of hot carriers, and the source and drain regions of an MOSFET in the input/output circuit have structure doped with phosphorus at a high impurity concentration, in order to enhance an electrostatic breakdown voltage.
摘要:
Disclosed is a semiconductor device having an internal circuit protected by an electrostatic protective circuit, the internal circuit and electrostatic protective circuit being formed on the same semiconductor substrate. The internal circuit includes MIS elements and has a double-diffused drain structure, while the protective circuit has a single-diffused drain structure. The internal circuit can be, e.g., a DRAM, and the protective circuit can have diffused resistors and clamping MIS elements. The single-diffused drain structure can be formed in the protective circuit on the semiconductor substrate, while providing double-diffused drain structure in the internal circuit on the same substrate, by: (1) scanning the ion implanting apparatus to avoid ion implantation of the first ions into the region of the protective circuit, and/or (2) forming a photoresist film over the region of the protective circuit to prevent ion implantation of the first ions into the protective circuit region. As a further embodiment of the present invention, a semiconductor integrated circuit device is provided wherein the source and drain regions of an MOSFET in the internal circuit have lightly doped drain (LDD) structure in order to suppress the appearance of hot carriers, and the source and drain regions of an MOSFET in the input/output circuit have structure doped with phosphorus at a high impurity concentration, in order to enhance an electrostatic breakdown voltage.
摘要:
Disclosed are memory cells of a vertical-type read only memory (ROM) having a plurality of MISFETs connected in series. The MISFETs include gate electrodes formed with multiple conductive layers, in which some of the MISFETs are set to the depletion type and at least some of the remaining MISFETs are set to the enhancement type, so as to write information in the memory cells. The information write operation is conducted through at least two steps. Namely, in the first information write step, gate electrodes are used as a mask to implant an impurity; and in the second step, an impurity is implanted through the gate electrodes into the surface of the semiconductor substrate. These steps enable a semiconductor memory device, such as a vertical-type mask ROM having memory cells with a reduced series resistance and being suitable for a high degree of integration, to be produced.Furthermore, there is disclosed a memory structure of a semiconductor memory device suitable for a higher degree of integration through an arrangement of gate electrodes of multiple layers.
摘要:
Vertical MISFETs are formed over drive MISFETs and transfer MISFETs. The vertical MISFETs comprise rectangular pillar laminated bodies each formed by laminating a lower semiconductor layer (drain), an intermediate semiconductor layer, and an upper semiconductor layer (source), and gate electrodes formed on corresponding side walls of the laminated bodies with gate insulating films interposed therebetween. In each vertical MISFET, the lower semiconductor layer constitutes a drain, the intermediate semiconductor layer constitutes a substrate (channel region), and the upper semiconductor layer constitutes a source. The lower semiconductor layer, the intermediate semiconductor layer and the upper semiconductor layer are each comprised of a silicon film. The lower semiconductor layer and the upper semiconductor layer are doped with a p type and constituted of a p type silicon film.