Method for manufacturing thin film actuated mirror array in an optical projection system

• US 6,204,080 B1
• Filed: 03/31/1998
• Issued: 03/20/2001
• Est. Priority Date: 10/31/1997
• Status: Expired due to Term

• Current Assignee: Wi-LAN Inc.
• Original Assignee: Daewoo Electronics (Government of South Korea)
• Inventors: Hwang, Kyu-Ho
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Rocchegiani, Renzo
• Application Number:
  US09/050,910
• Time in Patent Office: 1,085 Days
• Field of Search: 438/29, 359/224, 359/291, 359/850
• US Class Current: 438/29
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means

Abstract

A method for manufacturing a thin film AMA is disclosed. The second sacrificial layer is formed by using amorphous silicon, poly silicon or a material having fluidity and the first sacrificial layer is formed by using amorphous silicon or poly silicon. The light efficiency is enhanced by the reflecting member having an even surface after the first and the second sacrificial layers are formed in order to have even surfaces. In addition, the active matrix, the active layer and the reflecting member have no damages because the second sacrificial layer is removed by using the oxygen plasma or the vapor of bromine fluoride or xenon fluoride and the first sacrificial layer is removed by using the vapor of bromine fluoride or xenon fluoride.

Claims

1. A method for manufacturing a thin film actuated mirror array in an optical projection system, said method comprising the steps of:

providing an active matrix having i) a substrate including a metal oxide semiconductor transistor therein for a switching operation and ii) a first metal layer including a drain pad prolonged from a drain of the metal oxide semiconductor transistor, the active matrix being formed by a) forming a first passivation layer on said substrate and on said first metal layer, b) forming a second metal layer on said first passivation layer, c) forming a second passivation layer on said second metal layer and d) forming an etching stop layer on said second passivation layer;

forming a first sacrificial layer on said active matrix by a low pressure chemical vapor deposition method, the first sacrificial layer being comprised of at least one of an amorphous silicon and a poly silicon;

forming a supporting means having an anchor and a supporting layer after patterning said first sacrificial layer to expose a portion of said active matrix having the drain pad;

forming an actuator on said supporting means, said actuator having a bottom electrode, an active layer and a top electrode;

forming a second sacrificial layer on said actuator, the second sacrificial layer being comprised of at least one of an amorphous silicon and a poly silicon;

patterning said second sacrificial layer to expose a portion of said top electrode;

forming a post and a reflecting means on the exposed portion of said top electrode and on said second sacrificial layer;

removing said second sacrificial layer; and

removing said first sacrificial layer.

2. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 1, wherein the steps of removing said second sacrificial layer and removing said first sacrificial layer are performed by using at least one of a bromine fluoride vapor and a xenon fluoride vapor.

3. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 1, the step of forming said first sacrificial layer further comprising planarizing said first sacrificial layer by a chemical mechanical polishing method and the step of forming said second sacrificial layer further comprising planarizing said second sacrificial layer by a chemical mechanical polishing method.

4. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 1, wherein the steps of removing said second sacrificial layer and removing said first sacrificial layer are performed by using at least one of a bromine fluoride vapor and a xenon fluoride vapor.

5. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 1, wherein the step of forming said second sacrificial layer is performed by using a material having fluidity and by a spin coating method.

6. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 5, wherein the step of forming said second sacrificial layer is performed by using a material selected from the group consisting of a photo resist, a spin on glass (SOG) and a spin on polymer (SOP).

7. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 5, wherein the step of removing said second sacrificial layer is performed by using an oxygen plasma and the step of removing said first sacrificial layer is performed by using at least one of a bromine fluoride vapor and a xenon fluoride vapor.

8. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 1, wherein the steps of removing said second sacrificial layer and removing said first sacrificial layer are simultaneously performed.

9. A method for manufacturing a thin film actuated mirror array in an optical projection system, said method comprising the steps of:

providing an active matrix having i) a substrate including a metal oxide semiconductor transistor therein for a switching operation and ii) a first metal layer including a drain pad prolonged from a drain of the metal oxide semiconductor transistor;

forming a first sacrificial layer on said active matrix by using an amorphous silicon and by a low pressure chemical vapor deposition method;

forming a supporting means having an anchor and a supporting layer after patterning said first sacrificial layer to expose a portion of said active matrix having the drain pad;

forming an actuator on said supporting means, said actuator having a bottom electrode, an active layer and a top electrode;

forming a second sacrificial layer on said actuator by using a material selected from the group consisting of a photo resist, a spin on glass (SOG) and a spin on polymer (SOP), the second sacrificial layer being comprised of amorphous silicon;

patterning said second sacrificial layer to expose a portion of said top electrode;

forming a post and a reflecting means on the exposed portion of said top electrode and on said second sacrificial layer;

removing said second sacrificial layer by using an oxygen plasma, the second sacrificial layer being removed by using at least one of a bromine fluoride and a xenon fluoride; and

removing said first sacrificial layer, the first sacrificial layer being removed by using at least one of a bromine fluoride vapor and a xenon fluoride vapor.

10. A method for manufacturing a thin film actuated mirror array in an optical projection system, said method comprising the steps of:

providing an active matrix having i) a substrate including a metal oxide semiconductor transistor therein for a switching operation and ii) a first metal layer including a drain pad prolonged from a drain of the metal oxide semiconductor transistor;

forming a first sacrificial layer on said active matrix by using a poly silicon and by a low pressure chemical vapor deposition method;

forming a supporting means having an anchor and a supporting layer after patterning said first sacrificial layer to expose a portion of said active matrix having the drain pad;

forming an actuator on said supporting means, said actuator having a bottom electrode, an active layer and a top electrode;

forming a second sacrificial layer on said actuator by using a material selected from the group consisting of a photo resist, a spin on glass (SOG) and a spin on polymer (SOP), the second sacrificial layer being comprised of poly silicon;

patterning said second sacrificial layer to expose a portion of said top electrode;

forming a post and a reflecting means on the exposed portion of said top electrode and on said second sacrificial layer;

removing said second sacrificial layer by using an oxygen plasma, the second sacrificial layer being removed by using at least one of a bromine fluoride and a xenon fluoride; and

removing said first sacrificial layer, the first sacrificial layer being removed by using at least one of a bromine fluoride vapor and a xenon fluoride vapor.

11. The method for manufacturing the thin film actuated mirror array in an optical projection system as claimed in claim 10, the step of forming said first sacrificial layer further comprising planarizing said first sacrificial layer by a chemical mechanical polishing method and the step of forming said second sacrificial layer further comprising planarizing said second sacrificial layer by a chemical mechanical polishing method.