Method for depositing polycrystalline sige suitable for micromachining and devices obtained thereof

• US 20030124761A1
• Filed: 10/03/2002
• Published: 07/03/2003
• Est. Priority Date: 03/28/1997
• Status: Active Grant

• Current Assignee: IMEC International
• Original Assignee: Interuniversitair Micro-Electronica Centrum VZW (IMEC International)
• Inventors: Sedky, Sherif, Caymax, Matty, Witvrouw, Ann, Baert, Kris, Rusu, Cristina
• Granted Patent: US 7,176,111 B2
• Time in Patent Office: Days
• US Class Current: 438/50
• CPC Class Codes: B81C 1/00666 Treatments for controlling internal stress or strain in MEMS structures
• CPC Class Codes: B81C 2201/0164 by doping the layer
• CPC Class Codes: B81C 2201/017 Methods for controlling internal stress of deposited layers not provided for in B81C2201/0164 - B81C2201/0169
• CPC Class Codes: C23C 16/22 characterised by the deposition of inorganic material, other than metallic material
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01L 31/09 Devices sensitive to infrared, visible or ultraviolet radiation H01L31/101 takes precedence
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Method and apparatus to obtain as-deposited polycrystalline and low-stress SiGe layers. These layers may be used in Micro Electro-Mechanical Systems (MEMS) devices or micromachined structures. Different parameters are analysed which effect the stress in a polycrystalline layer. The parameters include, without limitation: deposition temperature; concentration of semiconductors (e.g., the concentration of Silicon and Germanium in a Si_xGe_1−x layer, with x being the concentration parameter); concentration of dopants (e.g., the concentration of Boron or Phosphorous); amount of pressure; and use of plasma. Depending on the particular environment in which the polycrystalline SiGe is grown, different values of parameters may be used.

Claims

12. Method according to claim 12, wherein the step of doping further comprises the step of annealing the semiconductor layer, the step of annealing being performed at a temperature to activate the dopants in the semiconductor layer.

13. Method according to claim 12, wherein the temperature to perform the step of annealing is greater than or equal to 450°

C.

14. Method according to claim 13, wherein the temperature to perform the step of annealing is less than or equal to 520°

C.

31. Method according to claim 12, wherein the Ge concentration (x) iii the semiconductor layer is within a range of 0.34 to 0.61.

32. Method according to claim 31, wherein the Ge concentration (x) in the semiconductor layer is within a range of 0.34 to 0.46.

15-1. Method according to claim 15, wherein the pressure is within a range of 0.3 to 2 Torr.