Method for producing microelectromechanical structures

A method for producing microelectromechanical structures, comprising the following steps:

• a) providing a first carrier substrate having one or more central layers and a surface, wherein the first carrier substrate is provided with a first insulation layer which is disposed on a first side of the one or more central layers and is formed on the surface;
• b) applying a first silicon layer to the first insulation layer;
• c) structuring the first silicon layer to form trenches in the first silicon layer, wherein the trenches extend at least in places through the first silicon layer;
• d) passivating the first silicon layer, wherein the trenches are filled and a first passivation layer forms on a side of the first silicon layer facing away from the first insulation layer;
• e) structuring the first passivation layer, wherein first sacrificial regions and first functional regions form in the first silicon layer and the first sacrificial regions on the side of the first silicon layer facing away from the first insulation layer are free of the first passivation layer at least in places;
• f) removing a part of the first carrier substrate in such a way that a new surface of the first carrier substrate is formed on a second side of the one or more central layers and none of the one or more central layers are removed;
• g) forming a second insulation layer on the new surface;
• h) repeating steps b to e for applying, structuring, and passivating a second silicon layer on the second insulation layer, structuring a second passivation layer to form second sacrificial regions and second functional regions in the second silicon layer;
• and
• i) removing all of the first and second sacrificial regions.

A microelectromechanical device, comprising:

• microelectromechanical structures including two alternating sequences of structured silicon layers and structured passivation layers;
• and
• a central layer which is disposed between the two alternating sequences of structured silicon layers and structured passivation layers;
• wherein the micromechanical structures are produced by performing the following steps:
• a) providing a first carrier substrate having the central layer and a surface, wherein the first carrier substrate is provided with a first insulation layer which is disposed on a first side of the one or more central layers and is formed on the surface,
• b) applying a first silicon layer to the first insulation layer,
• c) structuring the first silicon layer to form trenches in the first silicon layer, wherein the trenches extend at least in places through the first silicon layer,
• d) passivating the first silicon layer, wherein the trenches are filled and a first passivation layer forms on a side of the first silicon layer facing away from the first insulation layer,
• e) structuring the first passivation layer, wherein first sacrificial regions and first functional regions form in the first silicon layer and the first sacrificial regions on the side of the first silicon layer facing away from the first insulation layer are free of the first passivation layer at least in places,
• f) removing a part of the first carrier substrate in such a way that a new surface of the first carrier substrate is formed on a second side of the one or more central layers and none of the one or more central layers are removed,
• g) forming a second insulation layer on the new surface,
• h) repeating steps b to e for applying, structuring, and passivating a second silicon layer on the second insulation layer, structuring a second passivation layer to form second sacrificial regions and second functional regions in the second silicon layer, and
• i) removing all of the first and second sacrificial regions.