CMOS-compatible high-performance microscanners, including structures, high-yield simplified fabrication methods and applications

• US 20070026614A1
• Filed: 07/25/2006
• Published: 02/01/2007
• Est. Priority Date: 07/27/2005
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Garmire, David, Choo, Hyuck, Demmel, James, Muller, Richard
• Granted Patent: US 7,573,022 B2
• Time in Patent Office: Days
• US Class Current: 438/275
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

The present invention relates to systems and methods for fabricating microscanners. The fabrication processes employed pursuant to some embodiments are compatible with well known CMOS fabrication techniques, allowing devices for control, monitoring and/or sensing to be integrated onto a single chip. Both one- and two-dimensional microscanners are described. Applications including optical laser surgery, maskless photolithography, portable displays and large scale displays are described.

Claims

1. A method for fabricating a microscanner having interdigitated-comb actuators, comprising:

forming a thermal oxide layer on a semiconductor wafer; and

,

forming a rectangular pattern in said thermal oxide layer with a first photolithography mask, wherein the fixed-comb portion of an interdigitated-comb actuator will be defined; and

,

defining the fixed-comb and moving-comb portions of said actuator with a second photolithography mask and deep reactive ion etching; and

,

performing timed deep reactive ion etching to define the vertical height of said fixed-comb and moving-comb portions of said actuator; and

,

opening the backside of said actuator with a third photolithography mask and etching methods; and

releasing said actuator in an etch solution.

2. A method as in claim 1 further comprising fabricating at least one sensor integrally with said microscanner.

3. A method for projecting a pattern using torsional microscanners having interdigitated-comb actuators, comprising:

assembling a two-dimensional scanning system from two microscanners oriented at right angles to each other;

illuminating said scanning system with a pulsed laser;

driving said two microscanners with two sine waves wherein the phases of said sine waves are 90 degrees out of phase resulting in a circular pattern; and

causing said circular pattern to project onto a target.

4. A method as in claim 3 wherein the method is employed in optical laser surgery and said target is an ocular cornea.

5. A method as in claim 3 wherein the method is employed in maskless photolithography and said target is a photoresist covered substrate.

6. A method as in claim 3 wherein the method is employed in a portable raster-scanning display system and said target is a display surface.

7. A microscanner device comprising:

at least one microscanner; and

,

one or more integrated sensors on said device wherein said one or more integrated sensors measure the frequency and/or amplitude and/or temperature of said at least one microscanner; and

,

at least one controller receiving data from said one or more integrated sensors, wherein said at least one controller controls said at least one microscanner so as improve the performance of said device or to avoid damage thereto.

8. A microscanner device as in claim 7 wherein said one or more sensors comprises at least one temperature sensor integrated on said device and suitable for measuring the temperature of at least one of said one or more microscanners;

and

wherein said controller uses said temperature measurements to prevent damage, failure, and/or performance degradation of said device.