Method of producing semiconductor device and semiconductor device

• US 20070224706A1
• Filed: 12/14/2006
• Published: 09/27/2007
• Est. Priority Date: 03/27/2006
• Status: Abandoned Application

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited
• Inventors: Izumi, Kazutoshi
• Application Number:
  US11/638,422
• Publication Number:
  US 20070224706A1
• Time in Patent Office: Days
• US Class Current: 438/3
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer
• CPC Class Codes: H10B 53/00 Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors
• CPC Class Codes: H10B 53/30 characterised by the memory core region

Abstract

In the production of a semiconductor device in which a ferroelectric capacitor is used as a memory, a method of producing the semiconductor device in which the oxidation of a tungsten film embedded in an alignment mark prepared in the form of a groove is prevented includes forming an oxidation-preventing film composed of P—SiN (SiON) to cover the tungsten film prior to the formation of the ferroelectric capacitor, and heat-treating the oxidation-preventing film so as to thermally contract the film in advance.

Claims

1. A method of producing a semiconductor device having a ferroelectric capacitor used as a memory and an alignment mark prepared in a form of a groove, comprising the steps of:

embedding a tungsten(W) film in the groove of the alignment mark;

forming an oxidation-preventing film composed of P—

SiN (SiON) to cover the tungsten film; and

performing heat-treatment on the oxidation-preventing film so as to thermally contract the oxidation-preventing film prior to the formation of the ferroelectric capacitor.

2. A method of producing a semiconductor device as claimed in claim 1, further comprising the steps of:

performing etch back so as to remove a part of the tungsten(W) film at the groove peripheral part of the alignment mark.

5. A method of producing a semiconductor device as claimed in claim 1, wherein the oxidation-preventing film is a high-density plasma film.

6. A method of producing a semiconductor device as claimed in claim 1, further comprising a step of:

performing a plasma treatment using N₂ or N₂O in the range of 200°

C. to 450°

C. on the oxidation-preventing film.

7. A method of producing a semiconductor device as claimed in claim 1, wherein the oxidation-preventing film is formed by using SiH₄ or N₂O gas.

8. A method of producing a semiconductor device as claimed in claim 1, further comprising a step of:

forming a oxide film composed of P—

SiO after forming an oxidation-preventing film composed of P—

SiN (SiON),

wherein a range of refraction index of the oxide film is from 1.45 to 1.65.

9. A method of producing a semiconductor device as claimed in claim 1, further comprising a step of:

forming a hydrogen-diffusion-preventing film composed of Al₂O₃.

3. A method of producing a semiconductor device having a ferroelectric capacitor used as a memory and an alignment mark prepared in a form of a groove, comprising the steps of:

depositing the tungsten(W) film in the groove of the alignment mark;

polishing the tungsten(W) film by CMP to remove the tungsten(W) film outside of the alignment mark;

forming an oxidation-preventing film composed of P—

SiN (SiON) to cover the tungsten film;

polishing the oxidation-preventing film by CMP to remove oxidation-preventing film outside of the alignment mark; and

forming an oxidation-preventing film composed of P—

SiN (SiON) to cover the tungsten film prior to the formation of the ferroelectric capacitor.

4. A method of producing a semiconductor device having a ferroelectric capacitor used as a memory and an alignment mark prepared in a form of a groove, comprising the steps of:

depositing the tungsten (W) film in the groove of the alignment mark;

polishing the tungsten (W) film by CMP to remove the tungsten (W) film outside of the alignment mark; and

embedding an SOG film in the groove of the alignment mark.