EP1580837A1 - Semiconductor device with antenna and collecting screen - Google Patents

Abstract

The device has layers deposited on a silicon substrate (2) in which an antenna (5) is formed. A collector screen is formed within the layers, and collects currents induced between the antenna and the substrate. The screen has a main branch that is connected to a fixed potential, and secondary branches that are connected to the main branch so that the screen presents a tree-like structure. An independent claim is also included for an integrated circuit structure comprising a substrate layer.

Description

The present invention relates to the field of semiconductor devices.

It is known to realize signal transmitting / receiving antennas radioelectric devices on glass plates so as to constitute small sized components that are then associated on plates of connectivity to integrated circuit components or directly attached to such circuits. Such structures make it necessary to manufacture on the one hand integrated circuits and secondly antenna components and then to the associate.

The purpose of the present invention is to propose components for integrated circuits that also integrate transmitting / receiving antennas of radio signals and which are such that these antennas are of good quality even when radio signals are high frequencies.

The semiconductor device according to the invention comprises a substrate in particular silicon and layers made on this substrate in at least one of which an antenna is made transmitter / receiver of radio signals.

According to the invention, the semiconductor device comprises in in addition, between said antenna and said substrate, a collector screen of currents induced between this antenna and this substrate, this collector screen being made in at least one layer and comprising at least one main branch connected to a fixed potential, in particular a mass, and secondary branches only connected to said main branch by one of their ends so that this collector screen has a tree structure.

According to the present invention, said collector screen is preferably symmetrical with respect to an axis corresponding to the axis of the antenna.

According to the present invention, the main branch of said screen manifold preferably extends at least in part according to the strip input / output of the antenna.

According to the present invention, the main branch of said screen collector is shifted with respect to the zone or zones in which the antenna field is the strongest or the sensitivity of the latter is the strongest.

• la figure 1 représente une coupe longitudinale d'un dispositif semi-conducteur selon l'invention, selon I-I de la figure 2 ;
• la figure 2 représente une vue de dessus d'un écran collecteur selon l'invention ;
• la figure 3 représente une vue de dessus d'une antenne ;
• la figure 4 représente une vue de dessus d'un autre écran collecteur selon l'invention ;
• la figure 5 représente une vue de dessus d'un autre écran collecteur selon l'invention ;
• la figure 6 représente une vue de dessus d'un autre écran collecteur selon l'invention ;
• la figure 7 représente une vue de dessus d'une autre antenne ;
• et la figure 8 représente une vue .de dessus d'une autre antenne.

The present invention will be better understood in the study of semiconductor devices integrating radio signal transmitting / receiving antennas, described by way of nonlimiting examples and illustrated by the drawing in which:

• Figure 1 shows a longitudinal section of a semiconductor device according to the invention, according to II of Figure 2;
• FIG. 2 represents a view from above of a collector screen according to the invention;
• FIG. 3 represents a view from above of an antenna;
• FIG. 4 represents a view from above of another collector screen according to the invention;
• FIG. 5 represents a view from above of another collector screen according to the invention;
• FIG. 6 represents a view from above of another collector screen according to the invention;
• Figure 7 shows a top view of another antenna;
• and Figure 8 shows a view from above of another antenna.

Referring to Figures 1 to 3, it can be seen that there is shown a semiconductor device 1 which comprises a silicon substrate 2 on which are made different superimposed layers 3.

In layers near the substrate 2 is made a screen collector 4 and in a layer close to the final layer is achieved an antenna 5 transmitting / receiving radio signals.

The collector screen 4 is made in the following manner.

On the substrate 2 is formed a layer 3a.

In a fourth 3d layer, a branch is made main 6 which includes a longitudinal band 6a and two bands 6b and 6c inclined at 45 ° and symmetrically with respect to the direction of the longitudinal band 6a, so that the longitudinal band 6a and the two inclined strips 6b and 6c form a Y.

In a second layer 3b, a multiplicity of secondary branches 7 which are connected by vias 8 to the branch 6 and which determine with the latter a structure tree.

For this, this multiplicity of secondary branches 7 comprises a multiplicity of transverse bands 7a and 7b which extend from and other of the longitudinal band 6a of the main branch 6 and join in this band 6a, vias 8a connecting these junctions to the longitudinal band 6a.

The multiplicity of secondary branches 7 also includes a multiplicity of transverse bands 7c that extend externally to the area between the two inclined strips 6b and 6c of the main branch 6 and a multiplicity of longitudinal bands 7th which extend in this zone, such as the transverse bands 7c and the longitudinal strips 7e form L and join under the band 6b, vias 8b connecting these junctions to the inclined band 6b.

The multiplicity of secondary branches 7 further comprises a multiplicity of transverse bands 7d which extend externally to the area between the two inclined strips 6b and 6c of the branch principal 6 and a multiplicity of longitudinal bands 7f which extend into this zone, such as the transverse bands 7d and the longitudinal strips 7f form L and join under the strip 6c, vias 8c connecting these junctions to the inclined band 6b.

The transverse strips 7a and 7c on the one hand and the strips transversals 7b and 7d on the other hand are regularly distributed and the longitudinal bands are regularly spaced and are only connected to the main branch 6. The lengths of these bands are such they extend over a rectangular area.

Above the 3d layer is a 3rd layer in which is made a via 9 connected to the end portion of the strip 6a of the main branch 6 opposite its bands 6b and 6c and, above of this layer 3e is provided a layer 3f in which is performed a longitudinal band 10 connected to via 9.

Above the layer 3f is provided at least one layer 3g.

In a penultimate layer 3h is carried out the antenna 5 and above of this layer 3h is provided a last layer 3i of passivation.

In this example, the dipole antenna 5 comprises two strands 11 and 12 which comprise two longitudinal strips 11a and 12a which are close to each other and which extend parallel, above the longitudinal strip 6a of the collector screen 4, and two strips 11b and 12b which extend opposite each other.

The ends of the branches 11a and 12a of the antenna 5, opposite branches are connected to an integrated component not represented by means not shown, this component being a signal transmitter electrical when it is a signal-transmitting antenna radio or an electrical signal receiver when it comes an antenna receiving radio signals.

The antenna 5 and the collector screen 4 are arranged relative to each other to the other so that the junction area A strips 11a, 11b and 12a, 12b of the antenna 5 is above the junction zone E of the strips 6a, 6b and 6c of the collector screen 4.

The length of the transverse strips 11b and 12b of the antenna 5 is smaller than the length of the transverse strips 7a and 7b of the collector screen 4, so that the antenna 5 is completely covered by the collector screen 4.

The field of antenna 5 being the strongest or the sensitivity of the latter being the strongest in the zone of the aligned bands 11b and 11c, the strips 6a, 6b and 6c constituting the main branch 6 of the screen collector 4 are angularly offset with respect to the strips 11b and 12b of the antenna 5, the band 6a of 90 ° and the bands 6b and 6c of 45 °.

In a variant, the longitudinal strip 10 of the collector screen 4 extends to the opposite of the area covered by the latter so as to be connected to another part of the semiconductor device 1 to a fixed potential such as a mass.

In another variant, this longitudinal branch 10 could to be connected to the ground of the antenna 5 or the via 9 could be extended to be connected to the ground of the antenna 5.

The collector screen 4 has the function of collecting the currents induced by electrostatic coupling between the antenna 5 and the substrate in silicon 2. Its tree structure, which also has the same plan of symmetry that the antenna 5 in which the collector screen 4 and the antenna 5 have corresponding longitudinal axes of symmetry, avoids that the induced currents circulate in a loop.

Referring to Figures 4 to 6, we will now describe different variants of collector screens.

The collector screen 13 shown in FIG. 4 is made, unlike the previous example, in a single layer of the device semiconductor 1, for example in layer 3b.

This collector screen 13 comprises, like the collector screen 6, a main branch 14 which has a longitudinal band 14a and two inclined strips 14b and 14c.

This main branch 14 further comprises two strips 14d and 14th, inclined at 45 ° and opposite to the bands 14b and 14c, so that the strips 14a, 14b, 14c and 14d form a cross.

The collector screen 13 furthermore comprises a multiplicity of secondary branches 15 associated with the inclined bands 14a, 14b, 14c and 14d and which comprise longitudinal strips 15a and strips transversals 15b which, as in the previous example, constitute L spaced.

Thus, as in the previous example, the collector screen 13 has a tree structure whose bands 15a and 15b of its secondary branches 15 are only connected to the strips 14a, 14b, 14c and 14d of its main branch 14 by one of their ends, this collector screen 13 also extending over a rectangular area.

In this example, the area E of the collector screen 13, such as previously defined, is located at the center where at the junction point of the cross formed by the bands 14a, 14b, 14c and 14d of its branch main 14.

Referring to Figure 5, it can be seen that there has been shown a collector screen 16 which is also made in a single layer of semiconductor device 1.

This collector screen 16 comprises a main branch 17 which this time comprises only a longitudinal band 17a.

This collector screen 16 also includes a multiplicity of secondary branches 18 which include transverse bands opposed and spaced 18a and 18b connected by one of their ends to the longitudinal band 17a, so that this collector screen also has a tree structure that also extends over a rectangular area.

In this example, the area E of the collector screen 13, such as previously defined, is located at half the length of the band 17a constituting its main branch 17.

Referring to Figure 6, it can be seen that there is shown a collector screen 19 which is also made in a single layer of semiconductor device 1.

This collector screen 19 comprises a main branch 20 which this time includes a short longitudinal strip 20a and strips opposite transversals 20b and 20c which meet at the end of the longitudinal band 20a.

This collector screen 19 also includes a multiplicity of secondary branches 21 which comprise longitudinal strips spaced 21a connected by one of their ends to the transverse strip 20b, so that this collector screen also has a structure tree that also extends over a rectangular area.

In this example, the area E of the collector screen 13, such as previously defined, is located in the center of this rectangular area.

Referring to Figures 7 and 8, we will now describe different variants of transmitting / receiving antennas.

The antenna 22 shown in FIG. 7 comprises a first part 23 constituted by a central square zone 24 and a strip longitudinal longitudinal 25 of connection to a circuit of the semiconductor component 1, and a second portion 26 constituted by a zone broad surrounding at a short distance the periphery of the central zone 24 and extending to near the longitudinal band 25.

The field of the antenna 22 is the strongest or the sensitivity of this last is the strongest in the area of the space separating his area central 24 and its peripheral zone 26.

In this example, the area A of the antenna 22, as defined previously, is located in the center of the square zone 23.

The antenna 27 shown in FIG. 8 comprises a ring circular opening 28, the ends of which are connected to strips medial longitudinal axes 29 and 30 close to each other and connection to a circuit of the semiconductor component 1.

The field of the antenna 27 is the strongest or the sensitivity of this last is the strongest in the ring 28 area.

In this example, the area A of the antenna 27, as defined previously, is located in the center of the circular ring 28.

It follows from the foregoing that one can realize devices semiconductors by associating any of the collector screens 4, 13, 16 or 19 to any of the antennas 5, 22 or 27, in so that their area E is located below their zone A. Thus, the main branches of the collector screens are offset angularly or longitudinally with respect to the zones of stronger fields or stronger antenna sensitivities.

In addition, the surfaces covered by collector screens cover the surfaces of the antennas.

Moreover, the materials used to make the strips constituting the collector screens described above have a conductivity preferably between 0.1E7 and 6E7 S / m. We can advantageously realize them in aluminum, in tungsten or in polysilicon. In a preferred variant, the main branches of collector screens are metallic and their secondary branches are in polysilicon.

The materials used to make the antennas described previously can be selected from aluminum, copper, tungsten or gold.

These antennas can be calculated to present a range of a few centimeters to a few tens of meters and to emit or receive radio signals on particular frequencies greater than 2 gigahertz

The present invention is not limited to the above examples described. Many alternative embodiments are possible, in particular in concerning the tree structure of the collector screens or the antenna structure and their achievements in one or more layers, without departing from the scope defined by the appended claims.

Claims (4)

Semiconductor device comprising a substrate, in particular made of silicon, and layers formed on this substrate in at least one of which is formed an antenna transmitting / receiving radioelectric signals, characterized in that it furthermore comprises, between said antenna (5) and said substrate (2), a screen (4) collector induced currents between this antenna and this substrate, this collector screen being made in at least one layer and comprising at least one main branch (6) connected to a potential fixed, in particular a mass, and secondary branches (7) only connected to said main branch by one of their ends so that this collector screen has a tree structure. Device according to claim 1, the antenna being symmetrical about an axis, characterized in that said collector screen (4) is symmetrical with respect to an axis corresponding to the axis of the antenna (4). Device according to one of claims 1 and 2, characterized in that the main branch (6) of said collector screen (4) extends at least partly along the input / output band of the antenna (5) . Device according to any one of the preceding claims, characterized in that the main branch (6) of said collector screen (4) is offset relative to the zone or zones in which the field of the antenna (5) is the most where the sensitivity of the latter is the strongest.

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