SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20110294291A1
• Filed: 02/25/2011
• Published: 12/01/2011
• Est. Priority Date: 05/28/2010
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sato, Motoyuki, Eda, Hajime, Suguro, Kyoichi, Iwayama, Masayoshi, Kodera, Masako, Amano, Minoru, Matsui, Yukiteru, Yoshikawa, Masatoshi, Minamihaba, Gaku
• Application Number:
  US13/035,546
• Publication Number:
  US 20110294291A1
• Time in Patent Office: Days
• US Class Current: 438/672
• CPC Class Codes: H01L 21/02697 Forming conducting materials on a substrate
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/7684 Smoothing; Planarisation
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type

Abstract

According to one embodiment, a semiconductor device includes a switch element provided in a surface area of a semiconductor substrate, a contact plug with an upper surface and a lower surface, and a function element provided on the upper surface of the contact plug. The lower surface of the contact plug is connected to the switch element. The upper surface of the contact plug has a maximum roughness of 0.2 nm or less.

Claims

1. A semiconductor device comprising:

a switch in a surface area of a semiconductor substrate;

a contact plug with an upper surface and a lower surface, the lower surface connected to the switch, the upper surface having a roughness of 0.2 nm or less; and

a functional element on the upper surface of the contact plug.

2. The device of claim 1,

wherein the functional element is a magnetoresistive element which comprises:

a storage layer comprising a variable magnetization;

a reference layer comprising an invariable magnetization; and

a tunnel barrier layer between the storage layer and the reference layer,

wherein a roughness of a foundation of the tunnel barrier layer is 0.2 nm or less.

3. The device of claim 1,

wherein the reference layer comprises first and second ferromagnetic layers and a nonmagnetic layer therebetween, and

wherein magnetization directions of the first and second ferromagnetic layers are opposite to each other.

4. The device of claim 1,

wherein a foundation of the functional element comprises a material with a compressive stress.

5. A method of manufacturing a semiconductor device, the method comprising:

forming a contact plug by

forming a first metal material; and

polishing the first metal material by a CMP-process until a roughness of an upper surface of the contact plug becomes 0.2 nm or less, and

wherein the CMP-process is executed by using an acid-slurry comprising a colloidal silica.

6. The method of claim 5,

wherein the forming the contact plug is repeated twice or more.

7. The method of claim 5, further comprising:

forming the functional element on a lower electrode after forming the lower electrode on the contact plug,

wherein the forming the lower electrode comprises polishing a second metal material by the CMP-process after forming the second metal material on the contact plug.

8. The method of claim 5, further comprising:

forming the functional element on a lower electrode after forming the lower electrode on the contact plug,

wherein the forming the lower electrode comprises smoothing a second metal material by a gas cluster ion beam method after forming the second metal material on the contact plug.

9. A method of manufacturing a semiconductor device, the method comprising:

forming a contact plug by

polishing a first metal material using a CMP-process after forming the first metal material, and

smoothing the first metal material using a gas cluster ion beam method after the forming the contact plug,

wherein the polishing and the smoothing are executed until a roughness of an upper surface of the contact plug becomes 0.2 nm or less.

10. The method of claim 9,

wherein the polishing is repeated twice or more.

11. The method of claim 9, further comprising:

forming the functional element on a lower electrode after forming the lower electrode on the contact plug,

wherein the forming the lower electrode comprises smoothing a second metal material by a gas cluster ion beam method after forming the second metal material on the contact plug.