Infineon Technologies Ag

Andreas Felber

Valentin Rosskopf

Susanne Lachenmann

Bernhard Kowalski

Till Schloesser

Jürgen Lindolf

Juergen Lindolf

Bernd Goebel

Till Schlösser

Ulrich Frey

Sibina Sukman-Praehofer

Sibina Sukman

Valentine Rosskopf

Sibina Sukman-Prähofer

A semiconductor product having a test structure, in which a contact connection short-circuits that source/drain region of a transistor which is connected to an inner capacitor electrode of a trench capacitor by a dopant diffusion region with an interconnect is disclosed. Methods are disclosed for making an electrical measurement, to determine the nonreactive resistance of dopant diffusion regions, the so-called 'buried straps', without the measurement result being corrupted by the nonreactive resistance of a transistor channel. In accordance with one embodiment of the invention having a plurality of electrical connections of the capacitor electrode, static currents can also be conducted through a buried strap and the capacitor electrode. Embodiments are disclosed that make it possible to perform at novel test structures of a semiconductor wafer electrical resistance measurements, which cannot be carried out at memory cells of a memory cell array themselves.

Semiconductor product having a semiconductor substrate and a test structure and method

The invention relates to a semiconductor circuit () having an electrically programmable switching element (), an 'antifuse', which includes a substrate electrode (), produced in a substrate () which can be electrically biased with a substrate potential (Vo), and an opposing electrode () which is isolated from the substrate electrode () by an insulating layer (), where the substrate electrode () includes at least one highly doped substrate region (), and where the opposing electrode () can be connected to an external first electrical potential (V+) which can be provided outside of the semiconductor circuit (). In line with the invention, the substrate electrode () can be connected to a second electrical potential (V&#x2212;), which is provided inside the circuit and which, together with the external first potential (V+), produces a higher programming voltage (V) than the external first potential (V&#x2212;) together with the substrate potential (Vo). In addition, the substrate electrode () is shielded from the substrate potential (Vo) by a current barrier layer (). This allows the second potential to be lowered below the substrate potential or to be raised above it; the resulting increased programming voltage does not endanger other circuit regions.

Integrated semiconductor circuit with an electrically programmable switching element

A test structure for determining the electrical properties of a memory cell in a matrix-like cell array constructed on the basis of the single-sided buried strap concept has a connection between internal electrodes in the storage capacitors in two adjacent memory cells in the direction of the row of active regions in order to produce a series circuit. A first selection transistor and a first storage capacitor in a first memory cell and a second selection transistor and a second storage capacitor in a second memory cell, the active regions of the first and second selection transistors not being connected between the first and second selection transistors via a contact-making bit line.

Test structure for a single-sided buried strap DRAM memory cell array

An array process diagnosis test structure for an integrated circuit including a transistor array composed of vertical FET memory cell access transistors, which are formed into the depth of a substrate in the form of active webs which run parallel in the lateral direction of the circuit is disclosed. Memory cell storage capacitors in the array test structure are formed in deep trenches on the end faces of those sections of the active webs which form the vertical FET transistors. Word lines are arranged along the webs and along parallel intersecting bit lines of the array, outside of which, and on two mutually opposite edges, are located a first and second word line comb. The wordline combs are offset and connected alternately to different word lines. In addition, a first and a second bit line comb are formed on the two other opposing edges of the transistor array mutually offset and each connected to different bit lines. The test structure provides a convenient means to carry out reliability investigations on the gate oxide of the vertical FET transistors and on the capacitor dielectric in the deep trenches, capacitance measurements between the word lines, and between the word lines and other circuit layers, as well as capacitance measurements between the bit lines and between the bit lines and other circuit layers, and thus facilitates diagnosis of possible fault sources arising during the production process.

Device architecture and process for improved vertical memory arrays

An integrated circuit arrangement that has an integrated test structure is provided. The integrated circuit arrangement includes a transistor array having vertical FET selection transistors electrically coupled to storage capacitors of an assigned memory cell array, the storage capacitors being formed vertically into the depth of a substrate in deep trenches. The test structure may enable a plurality of vertical FET selection transistors by a conductive electrode material embedded in an extended deep trench. With a test structure of this type, it is possible to evaluate characteristic values for leakage currents and capacitances at different semiconductor junctions and also between different sections of the integrated circuit arrangement and also to perform reliability stress tests.

Test structure for improved vertical memory arrays

A test structure allows determining a short circuit between trench capacitors in a memory cell array in which the trench capacitors are arranged in matrix form. The test structure has, in two rows of trench capacitors, a connection of the trench capacitors of each row by tunnel structures and/or bridge structures. A contact area for contact connection is provided at each end section of a trench capacitor row.

Test structure for determining a short circuit between trench capacitors in a memory cell array

A test structure for determining a doping region of an outer capacitor electrode of a trench capacitor in a memory cell array. The trench capacitors of the memory cell array are arranged in matrix form. The test structure has two parallel rows of trench capacitors. The outer capacitor electrode of each row of trench capacitors is electrically connected to one another and the basic area of at least one trench capacitor of each row is lengthened on the side facing the other row in such a way that the two trench capacitors overlap in a direction transverse to their extent.

Test structure for determining a region of a deep trench outdiffusion in a memory cell array

A test structure for determining the resistance of a conducting junction between an active region of a selection transistor and a storage capacitor in a matrix-type cell array where the active regions of the selection transistors are in rows in a first direction and the storage capacitors are in rows in a second direction running perpendicular to the first direction. The conducting junctions between the active regions of the selection transistors and the storage capacitors are formed at overlapping areas of the mutually perpendicular rows each in a single edge region of the overlapping area in the first direction. The active regions of the selection transistors and/or the storage capacitors are connected by tunnel structures or bridge structures in the second direction in the region adjoining the junction to be measured between the active region of the selection transistor and the storage capacitor. This achieves a low-impedance connection to the junction to be measured.

Test structure for measuring a junction resistance in a DRAM memory cell array

A test structure for a memory cell array determines a doping region of an electrode connection that, in a memory cell, connects an inner capacitor electrode of a trench capacitor to an associated selection transistor. The test structure has an electrical contact with a predetermined contact area disposed between a regular matrix configuration of four trench capacitors.

Test structure for determining a doping region of an electrode connection between a trench capacitor and a selection transistor in a memory cell array

A transistor array has vertical FET transistors each connected to a storage capacitor of a memory cell array. Gate electrode strips, which form word lines, of the transistors are located on both sides of active webs running parallel to one another and are connected to a superimposed metal plane by word line or CS contacts. To insulate these word line contacts from the other elements of the transistor array and of the cell array, the word line contacts are located in deep trenches that are introduced into the webs.

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Dresden, Germany

Andreas Felber