Siemens Aktiengesellschaft

Ulrich Schwabe

Erwin P Jacobs

Franz Neppl

Ronald Rathbone

Konrad Hieber

Helmuth Murrmann

Peter Rydval

Christoph Werner

Adolf Scheibe

Dezso Takacs

Werner Christoph

Ulf Burker

Dezsoe Takacs

An integrated semiconductor circuit including a substrate consisting of silicon having a heavily doped impurity layer formed thereon. An interconnect level consisting of aluminum or aluminum alloy is connected to the contact regions by means of an intermediate layer consisting of tantalum silicide. The tantalum content of the compound is greater than that required stoichiometrically to produce the intermetallic compound TaSi.sub.2. The interconnect level is preferably in the form of an aluminum or aluminum alloy-tantalum silicide double layer. The tantalum silicide layer simultaneously acts as a diffusion barrier and as a contacting material. The lifetime of the electrically conducting paths under temperature and current stress as well as the reliability of the contacts is significantly increased in VLSI circuits as a result of this metallization.

Integrated semiconductor circuit having an external contacting track

Integrated semiconductor circuits with at least one bipolar transistor (17) and at least one MOS field effect transistor (18) on a chip wherein contacts from a metal interconnect level to diffused active emitter (8) and collector (5) regions of the bipolar transistor (17) as well as the gate electrode (9) of the MOS transistor are composed of a high melting point silicide, such as tantalum, tungsten, molybenum or titanium silicide, are disclosed, along with a method of producing such circuits. In addtion to achieving independence from a metallization grid and achieving low-resistance wiring, the use of the silicide, in conjunction with the high temperature stability of silicides, enables its simultaneous use as an implantation mask. The invention allows the production of bipolar/MOS components on a chip without added outlay.

Semiconductor circuit containing integrated bipolar and MOS transistors

A method for manufacture of gate electrodes formed of double layers of metal silicides having a high melting point and doped polycrystalline silicon. The polycystalline silicon is deposited in undoped fashion before the metal silicide and the doping of the silicon is obtained through the production of the source/drain-zones through ion implantation and a subsequent high temperature step. The method permits the problem-free manufacture of polycide-gates with n.sup.+ - and p.sup.+ -polysilicon on a chip without increased technological expense. Planarization is facilitated through the thin gate layers. The method is used in the manufacture of highly integrated CMOS-circuits.

Method for the manufacture of gate electrodes formed of double layers of

A method for the manufacture of a large scale integration (LSI) MOS field effect transistor wherein a gate electrode is generated on a doped silicon substrate, source/drain regions are formed by ion implantation using the gate electrode as an implantation mask and the source/drain regions are shielded by means of an oxide layer extending to the sidewalls of the gate electrode so that the diffusion of the implanted source/drain regions under the gate electrode area are reduced. The specific improvement of the present invention involves applying a readily flowable silicate glass layer as a gate edge masking for the source/drain ion implantation after formation of the gate electrode, the silicate glass layer being applied by deposition from the vapor phase at a thickness such that the dopant ions in the subsequent source/drain ion implantation are still implanted into the zone near the surface under the silicate glass layer but ion implantation into the zones at the edges of the gate is suppressed.

Method of making MOS FETs using silicate glass layer as gate edge

A manufacturing method for VLSI MOS field effect transistor circuits having digital and analog functions performed by short channel transistors and analog transistors integrated on one chip. An n-tube manufacture is performed wherein as soft as possible a field progression in front of a drain-side pn-junction of the analog transistor is achieved. This occurs by means of an additional drain implantation (curve II) with drive-in diffusion before the actual source/drain implantation (curve I) of the n-channel transistors. Both the additional implantation as well as the source/drain implantation are carried out with phosphorous ions. The dosage of the additional implantation lies one to two orders of magnitude below the dosage of the actual implantation, and the penetration depth x in the additional drive-in diffusion is about twice as great as the penetration depth x of the actual source/drain regions. The method is applied in the manufacture of VLSI CMOS circuits.

Method for the simultaneous manufacture of fast short channel and

A method for manufacturing a CMOS circuit wherein a process sequence matched to an n-tub manufacture is carried out. Short-channel properties of n-channel transistors are improved by performing double boron implantations of the channel regions. A single channel implantation is executed for both transistor types. Compared to traditional CMOS processes in n-tub structure, this eliminates involved masking steps. Also, the polysilicon gate is shielded from the boron ion implantation by means of a masking re-oxidation step and the under-diffusion given n-channel and p-channel transistors is greatly reduced by means of pull-back of the boron source/drain implantation. This contributes significantly to a symmetrical U.sub.T behavior of the transistors and to the attainment of high switching speeds. The method is used in the manufacture of VLSI CMOS circuits in VLSI technology.

Method of making CMOS circuits by twin tub process and multiple

A method for manufacturing VLSI complementary MOS field effect transistor circuits (CMOS circuits). By use of a suitable gate material, preferably a gate material comprised of silicides of high melting point metals, a threshold voltage of n-channel and p-channel CMOS-FETs having gate oxide thicknesses d.sub.GOX in a range of 10 to 30 nm is simultaneously symmetrically set by means of a single channel ion implantation. Given employment of tantalum silicide, the gate oxide thickness d.sub.GOX is set to 20 nm and the channel implantation is executed with a boron dosage of 3.times.10.sup.11 cm.sup.-2 and an energy of 25 keV. In addition to achieving a high low-level break down voltage for short channel lengths, this enables the elimination of a photolithographic mask. This represents an improvement with respect to yield and costs. The method serves for the manufacture of analog and digital CMOS circuits in VLSI technology.

Method for manufacturing VLSI complementary MOS field effect circuits

A method for the manufacture of integrated MOS-field effect transistor circuits in silicon gate technology and wherein diffusion source and drain zones are coated with a high melting point silicide as low-impedance printed conductors. The diffusion zones and polysilicon gates are made low-impedance through selective deposition of the metal silicide onto surfaces thereof. The selective deposition, which proceeds by use of a reaction gas eliminating hydrogen halide, simplifies the process sequence and is fully compatible with conventional silicon gate processes. Because of the high temperature stability, preferably tantalum silicide is employed. The invention is useful in the manufacture of MOS-circuits in VLSI-technology.

Method for the manufacture of integrated MOS-field effect transistor

The invention relates to a method for producing MOS transistors with flat source/drain zones, short channel lengths, and a self aligned contacting plane comprised of a metal silicide. In this method, the source/drain zones in the semiconductor substrate are produced by out-diffusion of the contacting plane consisting of a doped metal silicide and deposited directly on the substrate. The method serves to produce NMOS, PMOS, and in particular CMOS circuits in VLSI technology and permits a very high packing density and an independent additional wiring plane of very low resistance.

Method of making MOS device using metal silicides or polysilicon for

A method for producing integrated MOS field effect transistors, particularly complementary MOS field effect transistor circuits (CMOS-FET's) is provided wherein a metal silicide level, comprised preferably of tantalum silicide, is utilized as an additional interconnect (11). In this manner, all contact areas (9, 10, 13, 14, 15) to active (MOS) regions (6, 7) and polysilicon regions (5) for the metal silicide level (11) and also for the metal interconnect (12) are opened before the precipitation of the metal silicides. The structuring of the metal silicide level (11) is executed in such a manner that the p.sup.+ regions of the circuit remain protected during a flow-spread of an intermediate oxide (17) comprised of phosphorous glass.

Method for producing integrated MOS field effect transistors with an

Complementary MOS field effect transistor circuits are produced in silicon gate technology, with the method steps up to the structuring of the gate electrode being executed in a known manner. Both source/drain implantations (FIG. 3, 8 and FIG. 5, 10) occur with only one mask (7a). This mask (7a), which is composed of silicon nitride, is utilized for the source/drain implantation 8 of the n-channel transistors (9). The source/drain implantation (10) for the p-channel transistors (11) occurs without a mask and the oxide layer thickness, d.sub.6, over the source/drain regions of the n-channel transistors (9) functions as a masking layer. An advantage of this process sequence is that switched capacitor structures (FIG. 6, 5b, 12) can be simultaneously produced whereby the oxide layer thickness, d.sub.4, over the polysilicon-1 level (5a, 5b) determines the thickness of the insulating layer, d.sub.cox, of the capacitor structures (5b, 12). This technique is useful for manufacturing VLSI CMOS circuits in VLSI technology with and without switched capacitors.

Method for manufacturing VLSI complementary MOS field effect transistor

Analog or digital MOS circuits in VLSI technology are produced by a method in which the manufacture of two troughs (5, 8) occurs with only one mask (3) used in production of the p-trough (5). The n-trough (8) is formed by a surface-wide implantation (7) of an ion selected from a group consisting of P, As and Sb. The channel implantation of the p-transistors occurs simultaneously. The field (11) and channel (12) implantation of the n-channel transistors is carried out with a silicon nitride mask (9), i.e., a LOCOS mask, and a double boron implantation (10a, 10b). The field implantation (16) of the p-channel transistors is carried out with arsenic (15). Advantages of this process sequence include reduction of parasistic edge capacitances at the source/drain edges with fewer masking steps.

Method for producing VLSI complementary MOS field effect transistor

The invention provides a method for manufacturing adjacent tubs implanted with dopant material ions in the manufacture of LSI complementary MOS field effect transistor circuits (CMOS circuits), and also provides a method sequence for a CMOS process adapted to tub manufacture. In accordance with the principles of the invention, for the greatest possible spatial separation of the tubs, a p-tub (5) is produced before a n-tub (8) and an undercutting (25) of a nitride layer (4) serving as the implantation mask in the p-tub production is intentionally produced, so that, during a subsequent oxidation, the edge of the oxidation is shifted toward the outside by about 1 to 2 .mu.m. Further, the penetration depth x.sub.jn of the n-tub (8) is set smaller by a factor at least equal to 4 relative to the penetration depth x.sub.jp of the p-tub (5), whereby the thickness of the n-doped epitaxial layer (2) and the penetration depth x.sub.jp are about matched to one another. The two tubs are separately implanted and diffused. As a result of the inventive sequences, the disadvantages of mutual, extensive compensation of the p-tub and the n-tub are avoided.

Process for producing adjacent tubs implanted with dopant ions in the

A method for manufacturing MNOS memory transistors with very short channel lengths in silicon gate technology. In a substrate of a first semiconductor type, source and drain zones of MNOS and MOS components of a second conductivity type opposite the first conductivity type are provided. The edges of gate electrodes, with reference to the plane of the substrate surface, lie perpendicularly and self-adjusting over the edges of the source and drain zones, whereby the source and drain zones generated in the substrate are manufactured by means of ion implantation upon employment of the gate electrodes as the implantation mask.

Method of making very short channel length MNOS and MOS devices by

The invention relates to a MNOS memory cell arrangement in VLSI (very large scale integration) technology comprised of a multi-layer gate insulating layer covering a surface of a semiconductor body in the region between the source and drain zones. In order to avoid breakdowns at the source and drain zone edges before an erasure voltage is attained, the gate electrode is split into two electrodes, which can be operated in different ways and which are superimposed on upon another. These gate electrodes are connected via self-aligned, overlapped contacts. This arrangement resolves 'short channel erasure', even in the case of VLSI technology. The invention can be applied as required to MNOS EEPROM memory devices.

Growing community of inventors

Munich, Germany

Ulrich Schwabe