Method for filling trench with metal layer and semiconductor structure formed by using the same

• US 9,558,996 B2
• Filed: 09/09/2014
• Issued: 01/31/2017
• Est. Priority Date: 02/21/2012
• Status: Active Grant

• Current Assignee: United Microelectronics Corporation
• Original Assignee: United Microelectronics Corporation
• Inventors: Hsu, Chi-Mao, Huang, Hsin-Fu, Tsai, Min-Chuan, Chen, Chien-Hao, Chen, Wei-Yu, Lin, Chin-Fu, Li, Jing-Gang, Chen, Min-Hsien, Su, Jian-Hong
• Primary Examiner(s): Luu, Chuong A
• Application Number:
  US14/480,648
• Publication Number:
  US 20140374909A1
• Time in Patent Office: 875 Days
• Field of Search: 438/216, 438/653, 438/675, 438/678, 438/679, 438/680, 438/643
• US Class Current: 1/1
• CPC Class Codes: H01L 21/28079 the final conductor layer next to the insulator being a single metal, e.g. Ta, W, Mo, Al
• CPC Class Codes: H01L 21/28088 the final conductor layer next to the insulator being a composite, e.g. TiN
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate
• 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 filling a trench with a metal layer is disclosed. A deposition apparatus having a plurality of supporting pins is provided. A substrate and a dielectric layer disposed thereon are provided. The dielectric layer has a trench. A first deposition process is performed immediately after the substrate is placed on the supporting pins to form a metal layer in the trench, wherein during the first deposition process a temperature of the substrate is gradually increased to reach a predetermined temperature. When the temperature of the substrate reaches the predetermined temperature, a second deposition process is performed to completely fill the trench with the metal layer. The present invention further provides a semiconductor device having an aluminum layer with a reflectivity greater than 1, wherein the semiconductor device is formed by using the method.

Claims

1. A method for filling a trench with a metal layer, comprising:

providing a deposition apparatus, wherein the deposition apparatus comprises a heater;

providing a substrate and a dielectric layer disposed thereon, wherein the dielectric layer includes a trench;

performing a first deposition process to fill the trench with a metal layer, wherein a temperature of the substrate is ramped up from 15 degrees Celsius to 30 degrees Celsius to a predetermined temperature in the first deposition process, the predetermined temperature is between 380 degrees Celsius and 420 degrees Celsius and during the first deposition process, no heat transferring gas is supplied by the heater; and

performing a second deposition process when the temperature of the substrate reaches the predetermined temperature, so as to completely fill the trench with the metal layer, wherein the heater has the predetermined temperature and a heat transferring gas is supplied by the heater.

2. The method for filling the trench with the metal layer according to claim 1, wherein the second deposition is performed under the predetermined temperature.

3. The method for filling the trench with the metal layer according to claim 1, wherein during the first deposition process, the heater has the predetermined temperature and a gap is disposed between the heater and the substrate.

4. The method for filling the trench with the metal layer according to claim 1, wherein a deposition power of the first deposition process is substantially greater than that of the second deposition process.

5. The method for filling the trench with the metal layer according to claim 1, wherein a deposition power of the first deposition process is substantially equal to that of the second deposition process.

6. The method for filling the trench with the metal layer according to claim 1, further comprising:

after the second deposition process, a third deposition process is performed to increase a thickness of the metal layer, wherein a deposition power of the third deposition process is substantially greater than that of the second deposition process.

7. The method for filling the trench with the metal layer according to claim 6, wherein the deposition apparatus further comprises a heater and during the third deposition process, the heater has the predetermined temperature and a heat transferring gas is supplied by the heater.

8. The method for filling the trench with the metal layer according to claim 1, wherein the predetermined temperature is 400 degrees Celsius.

9. The method for filling the trench with the metal layer according to claim 1, wherein before the first deposition process is performed, at least a barrier layer is formed on the surface of the trench, wherein the barrier layer comprises Ti/TiN or Ta/TaN.