Sensor elements with cantilevered bar structures made of semiconductors based on group III-nitride

Semiconductor sensor element according to the preceding claim,

• characterised in that
• at least one of the contacts (5) is disposed in the region of the region (2a) (spaced region) of the homogeneous semiconductor layer (2, 2f), which region does not abut directly on the substrate base (1) or has a spacing from the surface of the substrate base (1) and in that at least one of the contacts (5) is disposed in the region of a region (2b) (non-spaced region) of the homogeneous semiconductor layer (2, 2f), which region does abut directly on the substrate base (1) or has no spacing from the surface of the substrate base (1).

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the homogeneous semiconductor layer (2, 2f) has a raised region or mesa region (9) which, in the direction perpendicular to the surface of the substrate base (1) orientated towards the homogeneous semiconductor layer (2, 2f), has a greater thickness than a region (non-mesa region) of the homogeneous semiconductor layer (2, 2f), which region abuts on this region (9) in a direction parallel to the surface of the substrate base (1) orientated towards the homogeneous semiconductor layer (2, 2f).

Semiconductor sensor element according to the preceding claim,

• characterised in that
• the raised region or mesa region (9) is disposed such that it extends in a direction parallel to the surface of the substrate base (1) orientated towards the homogeneous semiconductor layer (2, 2f) partially over the spaced region (2a) of the homogeneous semiconductor layer (2, 2f) and such that it extends partially over the non-spaced region (2b) of the homogeneous semiconductor layer (2, 2f.

Semiconductor sensor element according to the preceding claim,

• characterised in that
• the transition from the spaced region (2a) to the non-spaced region (2b) is effected in the direction parallel to the surface of the substrate base (1) orientated towards the homogeneous semiconductor layer (2, 2f) in the region of the centre of the raised region or mesa region (9).

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the substrate base (1) contains silicon Si or is formed therefrom.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the homogeneous semiconductor layer (2, 2f) contains semiconductor structures based on a main group III-nitride in the form of AlxGa1-xN or InxGa1-xN or InxA1-xN with a relative element content of 0<=x<=1.0 or is formed therefrom.

Semiconductor sensor element according to the preceding claim,

• characterised in that
• the homogeneous semiconductor layer (2, 2f) contains GaN or is formed therefrom.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• a spatial region present due to the spacing between the homogeneous semiconductor layer (2, 2f) and the substrate base (1) or between their surfaces orientated towards each other is not filled so that the semiconductor layer (2, 2f) relative to the substrate base is at least partially cantilevered.

Semiconductor sensor element according to the preceding claim,

• characterised in that,
• by means of the material, the heat transfer properties and/or the mechanical properties and/or the high frequency properties of the sensor element can be improved.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the homogeneous semiconductor layer (2, 2f) is undoped or p-doped or n-doped.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the extension of the homogeneous semiconductor layer (2, 2f) in a direction essentially perpendicular to its surface orientated towards the substrate base (1) is above 0.2 μm and/or below 50 μm, in particular above 0.5 μm and/or below 5 μm.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• there is disposed on or at the homogeneous semiconductor layer (2, 2f) on the side thereof orientated away from the substrate base, a cover layer (2e) of AlyGa1-yN or InyGa1-yN or InyAl1-yN with a relative element content of 0<=y<=1.0, in order to form a heterostructure of semiconductor compounds based on nitrides of the main Group III elements.

Semiconductor sensor element according to the preceding claim,

• characterised in that
• the further semiconductor layer is undoped or p-doped or n-doped.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the electrical conducting contacts (5) are p- and/or n-contacts.

Semiconductor sensor element according to the preceding claim,

• characterised in that
• an n-contact contains Al and/or Ti or is formed therefrom, the thickness of the contact being up to 1000 mm, particularly preferred up to 200 nm.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the electrical conducting contacts (5) have a metallisation.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the physical variable to be determined is the pressure, the temperature, a force, a deflection and/or an acceleration.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the change in the physical variable to be determined by the homogeneous semiconductor layer (2, 2f) via a change in the spatial state, shape, volume, structure of a surface and/or a deflection or bulge relative to the substrate base (1) of the semiconductor layer (2, 2f) can be converted directly into the electrical output signal.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the output signal can be generated by means of piezoelectric properties or mechanical changes in the lattice of the homogeneous semiconductor layer (2, 2f) or represents a change in charge carrier density on a surface of the homogeneous semiconductor layer (2, 2f or another electrical variable, in particular a current, a voltage or an electrical resistance.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the homogeneous semiconductor layer (2, 2f) is connected to the substrate base (1) at least one anchor point (3) or abuts on the substrate base (1) via at least one interface to the substrate base (1) such that at least one part (2a) of the part of the homogeneous semiconductor layer (2, 2f), which part is not connected at the anchor point or does not abut on the substrate base (1), can be deflected directly relative to the substrate base (1), by means of a change in the physical variable to be determined relative to the substrate base (1).

Semiconductor sensor element according to the preceding claim,

• characterised in that
• at least two anchor points (3) of the homogeneous semiconductor layer (2, 2f) have a connection in the form of a part (2b) of the homogeneous semiconductor layer (2, 2f), which part cannot be deflected relative to the substrate base (1) or has an interface to the substrate base (1).

Semiconductor sensor element according to the preceding claim,

• characterised in that
• the membrane (2c) is essentially circular or semicircular.

Semiconductor sensor element according to one of the preceding claims,

• characterised by
• at least two electrically connected homogeneous semiconductor layer elements.

Semiconductor sensor element according to one of the preceding claims,

• characterised in that
• the sensor element and/or the homogeneous semiconductor layer (2, 2f) is configured as a functional unit with integrated electrical or electronic circuits which have semiconductor structures based on a main Group III-nitride.

Semiconductor sensor element according to the preceding claim,

• characterised in that
• the circuits have diode structures and/or transistor elements and/or temperature sensor elements and/or in that the circuits are compensation circuits or amplifier circuits, in particular for signal amplification.

Measurement method for determining the change in a physical variable,

• a homogeneous semiconductor layer (2, 2f) which contains semiconductor compounds based on main Group III-nitride elements or is formed therefrom being disposed on or at a substrate base (1) such that the surface of the homogeneous semiconductor layer (2, 2f) orientated towards the substrate base (1) at least partially does not abut directly on the substrate base (1) or has a spacing from the surface of the substrate base (1) orientated towards the homogeneous semiconductor layer (2, 2f),
• characterised in that,
• on the basis of the change in the physical variable which is to be determined, an electrical output signal is generated by means of the homogeneous semiconductor layer (2, 2f), and in that this output signal is conducted via at least two electrical conducting contacts (5) which are disposed on, at and/or under the homogeneous semiconductor layer (2, 2f) or are integrated in this semiconductor layer (2, 2f).

Semiconductor structuring method according to the preceding claim,

• characterised in that
• the surface of the Si substrate base layer (1) at the boundary to the semiconductor layer sequence is a [111]-surface.

Semiconductor structuring method according to the preceding claim,

• characterised in that
• the halogens have chlorine and/or fluorine, in particular in the form of a CF4 plasma.

Use according to the preceding claim in the field of micromechanics or in the field of high-temperature applications or in the automotive field.