Siemens Aktiengesellschaft

Franz Neppl

Ulrich Schwabe

Josef Winnerl

Konrad Hieber

Erwin P Jacobs

Carlos-Alberto Mazure-Espejo

Christoph Zeller

Konrad Schober

Guenther Roeska

Werner Christoph

Ulf Burker

Carlos-Alb Mazure-Espejo

Heike Gierisch

Ulrich Schwabe, Deceased

C A Mazure-Espejo

Method for detaching chips in the silicon layer of a SOI substrate, wherein trenches are etched between the chips down to the insulating layer of the SOI substrate. Spacers for the passivation of SiO.sub.2 layers of the chips are produced. Finally, the chips are detached by etching the insulating layer off.

Method for detaching chips from a wafer

An integrated circuit containing bipolar and complementary MOS transistors wherein the base and emitter terminals of the bipolar transistor, as well as the gate electrodes of the MOS transistors, are composed of a silicide or of a double layer polysilicon silicide. The base and emitter terminals, as well as the gate electrodes, are arranged in one level of the circuit and there p.sup.+ doping or, respectively, n.sup.+ doping proceeds by ion implantation in the manufacture of the source/drain zones of the MOS transistors. As a result of the alignment independent spacing between the emitter and the base contact, the base series resistance is kept low and a reduction of the space requirement is achieved. Smaller emitter widths are possible by employing the polycide or silicide as diffusion source and as the terminal for the emitter. The size of the bipolar transistor is not limited by the metallization grid, since the silicide terminals can be contacted via the field oxide. The integrated semiconductor circuit is employed in VLSI circuits having high switching speeds.

Integrated circuit containing bi-polar and complementary MOS transistors

A circuit which contains integrated bipolar and complementary MOS transistors, including wells in the substrate for forming the MOS transistors, the wells also containing isolated bipolar transistors, the wells forming the collector of the bipolar transistor and being surrounded by trenches which are filled with doped polycrystalline silicon. The doped trench reduces the lateral out diffusion from the wells and thus serves to increase the packing density while serving as a collector contact region. The invention is employed in the manufacture of integrated semiconductor circuits having high switching speeds.

Circuit containing integrated bipolar and complementary MOS transistors

In an integrated circuit containing MOS transistors and/or bipolar transistors, the load resistors, which are arranged as thin-film elements on the field oxide zones which separate the active transistor zones, consist of polycrystalline silicon which is formed simultaneously with gate electrodes and/or the emitter and base terminal zones of the bipolar transistors on a substrate which contains the integrated circuit. The structuring of the load resistors is carried by way of an oxide mask which serves as an etch stop during the structuring of the gate electrode composed of a double layer of polysilicon and a silicide of a refractory metal. As only the polysilicon of the gate layer without overlying silicide is used for the load resistors, the sheet resistance of the load resistors can be set independently of that of the gates.

Method of making an integrated circuit comprising load resistors

For self-aligned manufacture of contacts referred to as vias between interconnects that are contained in wiring levels arranged above one another in an integrated circuit, a pillar technique is employed where the contacts are produced before the deposition of an inter-metal dielectric to produce the pillar, a layer structure is produced that contains at least one metal layer for the lower wiring level and at least one conductive layer for the contacts. The longitudinal expanse of the contact is defined by a mask that reliably overlaps the desired width of the lower interconnect. The transversal expanse of the contact is defined by the mask needed for producing the lower interconnect. The contacts and the lower interconnects are produced by step-by-step etching.

Method for self-aligned manufacture of contacts between interconnects

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

A double well CMOS process wherein the wells are separated by insulating trenches introduced into a semiconductor substrate, the position of the insulating trench along the isotropic under-etching in a silicon oxide layer employed together with a silicon nitride layer used as a masking layer in the implantation of the well which is first implanted. The trench itself is produced by anisotropic etching with silicon oxide masks used in the well implantations as etching masks. The trench width is defined with the isotropic etching and the trench depth is defined by the anisotropic etching. In this method, both well implantations and the trench etching are carried out with only one photo-technique. The implantation of the second well and the trench etching are self-adjusting. As a result, minimum spacings between the active zones are provided, and a space saving design is possible. The method is used in LSI CMOS processes.

Method for manufacturing wells for CMOS transistor circuits separated by

A metal-oxide-semiconductor (MOS) field effect transistor comprises monocrystalline, doped silicon zones which are formed between gate electrodes and the field oxide zones by selective epitaxy and which simultaneously serve as diffusion sources for the formation of source and drain zones in the substrate and as terminal zones for silicide source and drain terminals. This terminal technology serves to form particularly planar structures, with a high integration density, which structures are characterized by reduced drain field strength, low series resistances and a small danger of substrate short circuits. Processes for the formation of this structure in CMOS circuits are simple to perform. The present invention can be applied to all NMOS, PMOS and CMOS circuits.

Metal-oxide semiconductor (MOS) field effect transistor having extremely

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

An integrated circuit containing bipolar and complementary MOS transistors wherein the emitter terminals of the bipolar transistors as well as the gate electrodes of the MOS transistors are composed of the same material, consisting of a metal silicide or of a double layer containing a metal silicide and a polysilicon layer. The emitter base terminals are arranged in self-adjusting fashion relative to one another and the collector is formed as a buried zone. The collector terminal is annularly disposed about the transistor. As a result of the alignment in dependent spacing between the emitter and the base contact, the base series resistance is kept low and a reduction of the space requirement is achieved. The doping of the bipolar emitter and of the n-channel source/drain occurs independently. The method for the manufacture of the integrated circuit employs an n-doped gate material of the MOS transistors as a diffusion source and as a terminal for the emitters of the bipolar transistors and does not require an additional photolithography step. Because of the annular, deep collector region, a reduction of the collector series resistance and an increased latch-up hardness are achieved. The integrated semiconductor circuit is employed in VLSI circuits having high switching speeds.

Method of manufacturing integrated circuit containing bipolar and

A method for the manufacture of neighboring wells 9, implanted with dopant ions of differing conductivity type in silicon substrates provided with an epitaxial layer. A lateral under-etching having high selectivity to specified layers is designationally introduced into a silicon nitride layer provided for masking the n-well regions in the implantation of the p-wells. Thus, the edge of a silicon oxide layer serving as a masking in the following oxidation shifts in the direction of the n-wells. As a result of this type of self-adjusted well production, the influence of the counter-doping in the region of the well boundaries is noticeably reduced. In addition, a polysilicon layer can also be employed under the silicon nitride layer as a masking layer, this layer eing co-oxidized after the under-etching of the silicon nitride layer. Thus a box-shaped course is produced in the masking oxide instead of the prior art bird's bill course, whereby a steeper diffusion front is achieved in the n-well. The method serves for the manufacture of VLS1 complementary MOS field effect transistor circuits.

Methods for making neighboring wells for VLS1 CMOS components

A process for the production of highly integrated circuits contaiining p- and n-channel MOS transistors including gate electrodes which consist of a doped double layer of polysilicon and metal silicide. The gates are doped with boron and are produced by diffusion from the metal silicide layer which has previously been doped with boron by ion implantation into the undoped polysilicon layer. The metal silicide layer preferably consisting of tantalum silicide is provided with a masking layer consisting of SiO.sub.2, and the structuring of the boron-doped silicide gate and the masking layer is carried out after the boron atoms have been diffused in. The process serves to safely avoid undesired boron penetration effects which considerably influence the short channel properties of the transistors. The process is used for the production of CMOS-circuits having a high packing density.

Process for producing CMOS having doped polysilicon gate by outdiffusion

A method for the manufacture of LSI complementary MOS field effect transistor circuits to increase the latch-up hardness of the n-channel and p-channel field effect transistors while retaining good transistor properties by incorporating a further epitaxial layer and highly doped implantation regions into a lower epitaxial layer from which the wells are generated by out-diffusion into the upper epitaxial layer. In addition to achieving optimum transistor properties, the reduced lateral diffusion provided enables a lower n.sup.+ /p.sup.+ spacing, and thus achieves a higher packing density with improved latch-up hardness.

Forming retrograde twin wells by outdiffusion of impurity ions in

Cross-couplings between n-channel and p-channel CMOS field effect transistors of static write-read memories (SRAMs) with buried contacts to the n.sup.+ and p.sup.+ regions in the substrate are obtained in accordance with known method steps and with a high packing density. A gate level thereof formed of a polycide double layer is used as an additional wiring level for the cross-coupling. The formation of the gate level occurs after the opening of regions for the buried contacts. A doping occurs simultaneously with the generation of source/drain regions of the n-channel and p-channel transistors by masked ion implantation and a subsequent high-temperature treatment. Accordingly, simple, mask-non-intensive method steps result which are especially useful in the manufacture of 6-transistor SRAMs.

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Munich, Germany

Franz Neppl