1. Field of the Invention
The present invention relates to an integrated conductor arrangement, in particular a coaxial conductor arrangement, and a corresponding production method.
2. Description of the Prior Art
Without restricting the generality, the problem area on which the present invention is based is discussed with reference to coaxial conductors.
Radio frequency cables are designed as waveguides for radio frequency signal transmission which are employed at frequencies of typically up to 2 GHz.
A customary coaxial cable is a double line comprising two coaxial cylinders having a circular cross section. It comprises one or more coaxial pairs, in each coaxial pair the inner conductor, the dielectric, the outer conductor and the sheath being arranged coaxially. Advantages of coaxial cables are that no energy is radiated, and there is a relative insensitivity toward incident radiation.
It is an object of the present invention to provide an integrated conductor arrangement, in particular a coaxial conductor arrangement, and a corresponding production method which make it possible to produce integrated, in particular coaxially arranged and shielded, conductors on the chip.
The object is achieved in accordance with the invention by means of an integrated conductor arrangement, comprising:
a substrate;
at least one tubular conductor trench provided in the substrate below the top side of the substrate; and
a conductor, in particular coaxial conductor, integrated in the conductor trench;
the conductor having at least one tubular conductor layer.
The object is also achieved in accordance with the invention by means of a method for producing an integrated arrangement, comprising the steps of:
providing a substrate;
providing a patterned mask layer on the top side of the substrate;
etching a conductor trench and an adjoining contact trench, which has a larger diameter than the conductor trench, in the substrate using the patterned mask layer;
undercutting the patterned mask layer in order to form an expanded conductor trench and an adjoining expanded contact trench;
depositing an insulating outer insulator layer over the patterned mask layer, as result of which the walls of the expanded conductor trench and of the adjoining expanded contact trench are covered with the insulating outer insulator layer and the patterned mask layer is closed off in the region of the expanded conductor trench and remains open in the region of the expanded contact trench; and
depositing an at least one conductor layer, in particular successively depositing a conductive outer conductor layer, an insulating middle insulator layer and a conductive inner conductor layer in order to form a conductor, in particular a coaxial conductor, integrated in the conductor trench.
The idea on which the present invention is based consists in applying a deposition method, e.g. an ALD (Atomic Layer Deposition) deposition method, with the aid of which it is possible to uniformly coat long cavities of the substrate from the inside.
Consequently, conductors, in particular coaxial conductors, can be produced by first forming long tubelike channels in the substrate, which are open only at their ends and in which at least one conductor, preferably an outer conductor, an insulation and an inner conductor are formed progressively by the deposition method.
The arrangement of the tubelike channels in the substrate is arbitrary, that is to say a vertical (in particular through the chip), horizontal or arbitrarily angular course is conceivable. It is also possible, if necessary, for more than two conductors to be interleaved in one another.
The conductive outer conductor layer, the insulating middle insulator layer and the conductive inner conductor layer may be in each case closed annularly.
An insulating outer insulator layer may be provided between the conductive outer conductor layer and the substrate.
A contact trench (or hole) having a larger diameter than the conductor trench may be provided at at least one end of the conductor trench, the coaxial conductor being led through the contact trench to the top side of the substrate.
A contact trench having a larger diameter than the conductor trench may be provided at at least one end of the conductor trench, the conductive inner conductor layer being led through the contact trench to the top side of the substrate, and the conductive outer conductor layer being led from the conductor trench to the top side of the substrate.
FIGS. 2A-H are schematic sectional illustrations of successive method stages of a method for producing an integrated conductor arrangement, in particular coaxial conductor arrangement, in accordance with the first embodiment of the present invention, to be precise in each case along the line A-A′ and B-B′ in
FIGS. 3A-F are schematic sectional illustrations of successive method stages of a method for producing an integrated conductor arrangement, in particular coaxial conductor arrangement, in accordance with a second embodiment of the present invention, to be precise in each case along the line A-A′ and B-B′ in
In the figures, identical reference symbols designate identical or functionally identical component parts.
In
As a scale for this, the upper region of
Consequently, the contact trenches KB1 to KB4 in
In
FIGS. 2A-H show schematic sectional illustrations of successive method stages of a method for producing an integrated conductor arrangement, in particular coaxial conductor arrangement, in accordance with the first embodiment of the present invention, to be precise in each case along the line A-A′ and B-B′ in
The process state illustrated in
Referring further to
In a subsequent method step illustrated in
Afterward, in accordance with
Referring further to
Referring to
In the process step illustrated in
Referring further to
Although the conductor tracks LI, LA are depicted as non-shielded in the present example, it is possible, of course, also to shield these conductor tracks on the surface of the substrate.
FIGS. 3A-F show schematic sectional illustrations of successive method stages of a method for producing an integrated conductor arrangement, in particular coaxial conductor arrangement, in accordance with a second embodiment of the present invention, to be precise in each case along the line A-A′ and B-B′ in
In the second embodiment of the production method according to the invention, the starting point in accordance with
In this second exemplary embodiment, however, the conductive outer conductor layer 15 is removed in the region of the contact trench KB1′ prior to deposition of the insulating middle insulator layer 20 and the conductive inner conductor layer 25, as can be gathered from
The conductive outer conductor layer 15, by contrast, is contact-connected by a conductor track LA′ in the region of the conductor trench GB1′, to be precise after the outer insulator layer 10 has been removed in the through-plating region.
Since the opening that remains in the contact trench KB1′ at the top side is greater than in the case of the first exemplary embodiment, the deposition of the conductive inner conductor layer 25 is firstly carried out with high conformity, after which the conformity is lowered at the end in order to deposit the material with poorer edge coverage, so that it is possible to close the contact trench KB1′ with the conductive inner conductor layer 25.
Although the present invention has been described above on the basis of a preferred exemplary embodiment, it is not restricted thereto, but rather can be modified in diverse ways.
In particular, the invention can be applied in principle to arbitrary trench structures and material combinations.
The geometry of the contact holes can be chosen as desired, in particular also round or oval. Moreover, relative sizes other than those illustrated are possible.
Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted heron all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
Number | Date | Country | Kind |
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102005010513.0 | Mar 2005 | DE | national |