Infineon Technologies Ag

Peter Voigt

Gerhard Enders

Dietrich Bonart

Helmut Schneider

Bjoern Fischer

A buried strap contact between a trench capacitor of a memory cell and the subsequently formed selection transistor of the memory cell is fabricated such that the inner capacitor electrode layer is etched back in the trench of the trench capacitor and the uncovered insulator layer is then removed at the trench wall in order to define the region of the buried strap contact area. A liner layer is subsequently deposited in order to cover the inner capacitor electrode layer in the trench and the uncovered trench wall and thus to form a barrier layer. A spacer layer with the material of the inner electrode layer is then formed on the liner layer at the trench wall. Finally, the uncovered liner layer is removed above the inner electrode layer and the trench is filled with the material of the inner electrode layer in order to fabricate the buried strap contact.

Buried strap contact for a storage capacitor and method for fabricating it

A method for fabricating a gate structure of a FET, having: (a) deposition and patterning of a sacrificial layer sequence on a semiconductor substrate and uncovering of a gate section; (b) implantation of a channel doping into the gate section; (c) deposition and patterning of spacers at the sidewalls of the sacrificial layer sequence with the formation of a gate section that is not covered by the spacers; (d) introduction of a mask material into the gate section that is not covered by the spacers; (e) removal of the spacers selectively with respect to the sacrificial layer sequence and mask material); (f) implantation of a halo doping in regions uncovered by the removed spacers; (g) removal of the mask material; (h) formation of a gate on the gate section; and (j) removal of the sacrificial layer sequence selectively with respect to the gate.

Method for fabricating a gate structure of a FET and gate structure of a FET

A method for fabricating a semiconductor gate structure including depositing at least one sacrificial layer on a semiconductor substrate; patterning the at least one sacrificial layer to form at least one cutout in the at least one sacrificial layer for uncovering the semiconductor substrate; forming a sidewall spacer over the sidewalls of the at least one sacrificial layer in the at least one cutout; forming a gate dielectric on the semiconductor substrate in the cutout; providing a gate electrode in the at least one cutout in the at lest one sacrificial layer; and removing the at least one sacrificial layer for the uncovering the gate electrode surrounded by the sidewall spacer. A semiconductor device is also provided.

Semiconductor gate structure and method for fabricating a semiconductor gate structure

The present invention relates to a method for producing a vertical transistor, and to a vertical transistor. A sacrificial gate oxide and a sacrificial gate electrode are used during the production of the vertical transistor to makes it possible to considerably reduce or entirely avoid negative effects that normally result from the production of insulation structures between the vertical transistors. In particular, broadening of the gate oxide at the edge of the gate electrode can be prevented, and the edge of the gate electrode can be influenced deliberately. This allows vertical transistors to be produced having a current/voltage characteristic that can be adjusted specifically. In particular, vertical transistors can be produced having a pronounced corner effect.

Vertical transistor, and a method for producing a vertical transistor

A field-effect transistor includes a semiconductor substrate, a source region formed in the semiconductor substrate, a drain region formed in the semiconductor substrate, a channel region formed in the semiconductor substrate, wherein the source region is connected to a source terminal electrode and the drain region is connected to a drain terminal electrode, wherein the channel region comprises a first narrow width channel region and a second narrow width channel region connected in parallel regarding the source terminal electrode and the drain terminal electrode, and wherein the first narrow width channel region and/or the second narrow width channel region comprise lateral edges narrowing the width of the narrow width channel region is such a way that a channel formation in the narrow width channel region is influenced by a mutually influencing effect of the lateral edges, and a gate electrode arranged above the first and second narrow width channel regions.

Field-effect transistor

A semiconductor memory is fabricated with a vertical transistor situated in an upper section of a trench above a trench capacitor. First, an auxiliary insulation layer is applied to the conductive material of an inner electrode or to a connecting material of the trench capacitor. The connecting material is situated on the inner electrode, so that, during an epitaxial deposition, semiconductor material grows only on the uncovered sidewalls in the upper section of the trench. A nitride layer, is deposited conformally and the residual cavity between the inner electrode and the epitaxial semiconductor layer is filled with a doped further conductive material. The nitride layer isolates the epitaxial semiconductor layer from the further conductive material, so that no crystal lattice defects can propagate from there into the epitaxial semiconductor layer. Dopants are outdiffused from the further conductive material into the epitaxial semiconductor layer to form a doping region.

Method for fabricating a vertical transistor, and semiconductor memory cell having a trench capacitor and an associated vertical selection transistor

A trench cell for use in a DRAM array includes a vertical selection transistor of a first conductivity type at the&mdash;seen in the bit line direction&mdash;first side of the trench hole, a blocking doping region near the surface, of a second conductivity type, is provided adjacent to the trench hole, the blocking doping region lying opposite the vertical selection transistor. As a result, leakage currents can be avoided and, in addition, the trench cells can be disposed at a shorter distance from one another.

Trench cell for a DRAM cell array

A method is provided for manufacturing a buried strap contact between a transistor and a trench capacitor in a memory cell, particularly a DRAM memory cell. In this method, the two spacers of the gate electrode lying opposite one another and the gate path applied on the trench insulation of the memory cell serve as part of the mask that is employed for etching the contact trench and in which the buried bridge of the trench capacitor is subsequently generated. As a result, the position of that sidewall of the bridge facing toward the gate electrode is generated in self-aligning fashion relative to the gate electrode. This avoids photolithographic tolerances in the positioning of the bridge relative to the gate electrode.

Method for manufacturing a buried strap contact in a memory cell

For particularly simple and targeted formations of a diffusion region, an interfacial region of a semiconductor substrate is subjected to a thermal transformation process and thereby carry out the thermally activated diffusion of a dopant in a substantially directed form, in particular in substantially a preferential direction, by interaction of a provided dopant with a transforming interfacial region.

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Hallbergmoos, Germany

Peter Voigt