Bond structures on MEMS element and ASIC element
A MEMS element is provided. The MEMS element includes: a substrate; a first passivation layer arranged on the substrate; a metal layer arranged on the first passivation layer; a second passivation layer arranged on the metal layer and on the first passivation layer; and a punch element, an electrically conductive diffusion-blocking layer being arranged on the punch element and on the second passivation layer, a first bonding element being arranged on the punch element.
1. A device comprising:
an ASIC element, the ASIC element comprising:
a first substrate;
an ASIC functional layer arranged on the first substrate;
a first metal layer arranged on the ASIC functional layer;
an oxide layer having vias;
a first bonding element; and
a first passivation layer that is arranged on the oxide layer and that includes a spacer element that forms a trough (a) in which the first bonding element is arranged, (b) into which a second bonding element is able to be plunged during a eutectic bonding process, and (c) that prevents an outflow of eutectic material of the eutectic bonding process from the trough.
2. The device as recited in claim 1 , wherein a metal structure, which is separated from the first bonding element, is formed in the passivation layer.
3. The device as recited in claim 1 , further comprising:
a micromechanical sensor, the micromechanical sensor comprising a MEMS element that includes:
a second substrate;
a second passivation layer arranged on the second substrate;
a second metal layer arranged on the second passivation layer;
a third passivation layer partially arranged on the second metal layer and partially arranged on the second passivation layer; and
a punch element;
an electrically conductive diffusion-blocking layer partially arranged on the punch element and partially arranged on the third passivation layer; and
the second bonding element, the second bonding element being arranged on the punch element;
wherein the eutectic bonding process eutectically bonds the ASIC element to the MEMS element.
4. The device as recited in claim 1 , wherein the first bonding layer that is arranged in the trough is arranged on the oxide layer.
5. The device as recited in claim 3 , wherein a material of the punch element is aluminum or a dielectric material.
6. The device as recited in claim 3 , wherein the diffusion-blocking layer is diffusionally stable relative to the second bonding element.
7. The device as recited in claim 3 , wherein the diffusion-blocking layer includes notches in a planar area.
8. The device as recited in claim 3 , wherein the diffusion-blocking layer includes two partial blocking layers.
9. The device as recited in claim 8 , wherein a first one of the two partial blocking layers is structured.
10. The device as recited in claim 5 , wherein the punch element is arranged on the second passivation layer.
11. The device as recited in claim 3 , wherein the punch element is arranged on an opening of the third passivation layer.
12. The device as recited in claim 3 , wherein the punch element is arranged on the second passivation layer, mutually delimited openings of the first second passivation layer being arranged around the punch element, the diffusion-blocking layer being arranged on the third passivation layer and on the openings of the second passivation layer.
13. The device as recited in claim 3 , wherein a material of the punch element is a dielectric material, and the diffusion-blocking layer is structured.
14. A method for manufacturing a micromechanical sensor, comprising the following steps:
providing a sensor element;
producing a device by:
providing a MEMS element;
providing an ASIC element that includes (I) a first substrate, (II) an ASIC functional layer arranged on the first substrate, (III) a first metal layer arranged on the ASIC functional layer, (IV) an oxide layer having vias, (V) a first bonding element, (VI) a first passivation layer that is arranged on the oxide layer and that includes a spacer element that forms a trough in which the first bonding element is arranged; and
performing a eutectic bonding process that bonds the MEMS element to the ASIC element and during which a second bonding element, which is part of the MEMS element, is plunged into the trough;
wherein:
the trough prevents an outflow of eutectic material of the eutectic bonding process from the trough; and
the device includes an electrical feed to the sensor element.
15. The method as recited in claim 14 , wherein:
the MEMS element includes a dimensionally stable punch element on which the second bonding element is arranged; and
during the eutectic bonding process, the punch element is plunged into the trough and the spacer element establishes a separation between the MEMS element and the ASIC element.