Method for producing a micromechanical structure and a micromechanical structure

• US 20020055253A1
• Filed: 11/05/2001
• Published: 05/09/2002
• Est. Priority Date: 11/09/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Rudhard, Joachim
• Granted Patent: US 6,436,821 B1
• Time in Patent Office: Days
• US Class Current: 438/672
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 3/0008 Structures for avoiding electrostatic attraction, e.g. avoiding charge accumulation
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: B81C 2201/112 Depositing an anti-stiction or passivation coating, e.g. on the elastic or moving parts

Abstract

A method for producing a micromechanical structure, and a micromechanical structure having a movable structure and a stationary structure made of silicon. In the method for producing the micromechanical structure, in one process step, a superficial metal-silicide layer is produced in the movable structure and/or the stationary structure.

Claims

1. A method for producing a micromechanical structure, comprising:

introducing trenches into a silicon layer for forming at least one movable structure and at least one stationary structure from the silicon layer, the movable structure being movable relative to the stationary structure;

after introducing the trenches, depositing a metal layer on side walls of the trenches;

after depositing the metal layer, carrying out a thermal treatment by which metal of the metal layer forms a metal silicide with silicon of the silicon layer; and

subsequently carrying out an etching process which removes the metal of the metal layer and does not remove the metal silicide.

2. The method according to claim 1, wherein the metal layer is composed of one of titanium, zirconium, hafnium, vanadium, chromium, niobium, tantalum, molybdenum, tungsten, cobalt, nickel, palladium and platinum.

3. The method according to claim 1, wherein the silicon layer is composed of one of polycrystalline silicon and monocrystalline silicon.

4. The method according to claim 1, wherein the silicon layer is arranged on a sacrificial layer.

5. The method according to claim 4, wherein the sacrificial layer is arranged on a support, the support being composed of one of silicon and glass.

6. The method according to claim 1, wherein the thermal treatment is carried out at a temperature between 400°

and 800°

C.

7. A micromechanical structure comprising:

at least one stationary structure; and

a movable structure movable relative to the stationary structure,

wherein the movable structure and the stationary structure are composed substantially of silicon, and

wherein at least one of the movable structure and the stationary structure has a superficial metal-silicide layer.