Semiconductor device

• US 7,795,619 B2
• Filed: 05/27/2005
• Issued: 09/14/2010
• Est. Priority Date: 01/31/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Inventors: Hara, Akito
• Primary Examiner(s): Lee; Eugene
• Assistant Examiner(s): Ho; Anthony
• Application Number:
  US11/138,431
• Publication Number:
  US 20060170046A1
• Time in Patent Office: 1,936 Days
• Field of Search: 257/67, 257/347, 438/149, 438/152, 438/155, 438/479, 438/517
• US Class Current: 257/67
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/84 the substrate being other than a semiconductor body, e.g. being an insulating body
• CPC Class Codes: H01L 23/53228 the principal metal being copper
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method for manufacturing a semiconductor device, including the steps of: forming a shielding film 38 on a first insulating film 37; sequentially forming a second insulating film 39 and an amorphous semiconductor film 40 on the shielding film 38; melting the amorphous semiconductor film 40 at least in portions to be channels of thin-film transistors by irradiating an energy beam onto the amorphous semiconductor film 40, and converting the amorphous semiconductor film 40 into a polycrystalline semiconductor film 41; sequentially forming a gate insulating film 43a and a gate electrode 44a on the polycrystalline semiconductor film 41 on the channels; and forming source and drain regions 41a in the polycrystalline semiconductor film 41 on sides of the gate electrode 44a, and forming a TFT 60 by use of the source and drain regions 41a, the gate insulating film 43a, and the gate electrode 44a.

Claims

1. A semiconductor device comprising:

a semiconductor substrate;

an interlayer insulating film formed over the semiconductor substrate;

wirings formed on the interlayer insulating film;

a first insulating film formed on the wirings and the interlayer insulating film;

a shielding film formed on the first insulating film, the shielding film is not electrically connected to the wirings and to the semiconductor substrate, and the shielding film made of an element or alloy of Al, Au, Ag, Pt, Cu, Mo, Ta, Ti, or W and does not contain silicon;

a second insulating film formed on the shielding film; and

a thin-film transistor which is formed on the second insulating film and has a polycrystalline semiconductor film as a channel.

2. The semiconductor device according to claim 1, wherein the shielding film has a function to do any of reflection and attenuation of an energy beam.

3. The semiconductor device according to claim 1, wherein the shielding film is in an electrically floating state.

4. The semiconductor device according to claim 1, wherein a MOS transistor is formed on the semiconductor substrate and the interlayer insulating film is formed on the MOS transistor.

5. A semiconductor device comprising:

a semiconductor substrate;

an interlayer insulating film formed over the semiconductor substrate;

wirings formed on the interlayer insulating film;

a first insulating film formed on the wirings and the interlayer insulating film;

a shielding film formed on the entire surface of the first insulating film, the shielding film is not electrically connected to the wirings and to the semiconductor substrate, and the shielding film made of an element or alloy of Al, Au, Ag, Pt, Cu, Mo, Ta, Ti, or W and does not contain silicon;

a second insulating film formed on the shielding film; and

a thin-film transistor which is formed on the second insulating film and has a polycrystalline semiconductor film as a channel.