DE102014205536A1 - Micromechanical device with non-stick layer and corresponding manufacturing method - Google Patents

Abstract

The invention provides a micromechanical component with non-stick layer (A) and a corresponding production method. According to the invention, the non-stick layer (A) consists of molybdenum disulfide.

Description

The invention relates to a micromechanical device with non-stick layer and a corresponding manufacturing method.

State of the art

Although applicable to any micromechanical components, the present invention and its underlying problem will be explained with reference to silicon-based devices.

In the manufacture or use of micromechanical devices, such as sensor devices, there is often the risk of so-called sticking problem of the moveable structure on fixed structures of the device. Such sticking occurs when the Oberflächenadhäsivkräfte are greater than the mechanical restoring forces of a deflectable micromechanical structure.

The sticking problem can be solved by using a non-adhesive layer with low adhesion force, for example in the form of an organic passivation layer on an inorganic surface such as silicon, such as EP 2 057 093 A1 or the WO2006 / 015901 A1 known.

Currently common anti-stiction coatings are self-assembling organic compounds based on a combination of carbon (C), fluorine (F) and hydrogen (H). Although the non-stick properties of the known non-stick layers are more than adequate, their thermal stability at temperatures above 500 ° C is not guaranteed. This reduces the thermal budget, which is still present after the application of such anti-adhesive layers for the further processing of the respective micromechanical components.

MoS ₂ (molybdenum disulfide) has long been known and widely used as a solid lubricant, such as in the EP 0 205 762 B1 described.

DE 60 027 401 T2 describes a radical-assisted sequential vapor deposition using the molybdenum pentachloride as a precursor.

Disclosure of the invention

The invention provides a micromechanical component with an anti-adhesion layer according to claim 1 and a corresponding production method according to claim 6.

Preferred developments are the subject of the respective subclaims.

Advantages of the invention

The idea underlying the present invention is to provide a monolayer or a few layers of MoS ₂ as an anti-adhesion layer in micromechanical devices susceptible to sticking in order to increase the thermal budget of post-processing after coating. MoS ₂ has a thermal decomposition temperature of 1185 ° C and therefore allows a substantial increase in the thermal budget for post-processing. It has been found that MoS ₂ has excellent non-stick properties with such micromechanical components even at very low layer thicknesses.

According to a preferred development, the non-stick layer has a thickness of one monolayer or several layers. Already with such low layer thicknesses, excellent non-stick properties can be achieved.

MoS ₂ can be deposited by a purely thermal process in self-assembling monolayers or a few layers, such. As described in Controlled Scalable Synthesis of Uniform, High-Quality Monolayer and Few-layer MoS ₂ Films, Scientific Reports 3, Article Number: 1866 doi: 10.1038 / srep01866.

According to a further preferred development, a first component and a second component are provided, which are mutually elastically deflectable.

According to a further preferred development, the first component is a semiconductor substrate and the second component is a micromechanical sensor structure.

According to a further preferred development, the first component and the second component consist of silicon.

Brief description of the drawings

Further features and advantages of the present invention will be explained below with reference to embodiments with reference to the figures.

Show it:

1a ), b) schematic cross-sectional views for explaining a micromechanical device with non-stick layer and a corresponding manufacturing method according to an embodiment of the present invention.

Embodiments of the invention

In the figures, like reference numerals designate the same or functionally identical elements.

1a ), b) are schematic cross sectional views for explaining a micromechanical device having an anti-adhesion layer and a corresponding manufacturing method according to an embodiment of the present invention.

In 1a ) denotes reference numeral 1 a semiconductor substrate made of silicon, above which a movable micromechanical functional component 1a , For example, an acceleration sensor is provided. The movable, elastically deflectable component 1a is via a connection, not shown, with the semiconductor substrate 1 connected.

For the deposition of an anti-adhesion layer A is according to 1a ) in a container B, a mixture L of the molybdenum pentachloride and sulfur as precursors by means of a heater H to about 850 ° C heated.

Through this thermal process, the precursors are vaporized and self-assemble on the surface of the semiconductor substrate 1 and the movable component 1a as a monolayer or multiple layers MoS ₂ , which has excellent non-stick properties.

By the non-stick layer A from MoS ₂ can be sticking of the movable component 1a on the semiconductor substrate 1 avoid even when touching both components.

Although the present invention has been described in terms of preferred embodiments, it is not limited thereto. In particular, the materials and topologies mentioned are only examples and not limited to the illustrated examples.

Although a micromechanical structure based on silicon has been described in the above embodiment, the invention is not limited thereto, but applicable to any micromechanical materials.

Also, the deposition process of MoS ₂ is not limited to the described thermal process, but is replaceable by any other efficient deposition method of MoS ₂ , such as MoS ₂ . B. Sulfurization of MoO ₃ layers, thermolysis of Mo compounds, etc.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2057093 A1 [0004]
• WO 2006/015901 A1 [0004]
• EP 0205762 B1 [0006]
• DE 60027401 T2 [0007]

Claims (10)

 Micromechanical component with non-stick layer (A), wherein the non-stick layer (A) consists of molybdenum disulfide. Micromechanical component according to claim 1, wherein the non-stick layer (A) has a thickness of one monolayer or more layers. Micromechanical component according to Claim 1 or 2, which comprises a first component ( 1 ) and a second component ( 1a ), which are mutually elastically deflectable. Micromechanical component according to claim 2, wherein the first component ( 1 ) a semiconductor substrate and the second component ( 1a ) is a micromechanical sensor structure. Micromechanical component according to claim 3 or 4, wherein the first component ( 1 ) and the second component ( 1a ) consist of silicon.  Manufacturing method for a micromechanical component with non-stick layer (A) with the steps: Providing the uncoated micromechanical device; and Depositing the non-stick layer (A) of molybdenum disulfide on the surface of the micromechanical device.  The manufacturing method according to claim 6, wherein for deposition, a mixture of molybdenum pentachloride and sulfur is heated to a temperature between 800 and 900 ° C, preferably about 850 ° C. The manufacturing method according to claim 6, wherein said depositing is sulfurization of molybdenum trioxide layers. A manufacturing method according to claim 6, wherein a thermolysis of a molybdenum compound is carried out for deposition. The manufacturing method according to any one of claims 6 to 9, wherein the non-stick layer (A) has a thickness of one monolayer or more layers.

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