Method of silicon oxide and silicon glass films deposition

• US 6,197,705 B1
• Filed: 03/18/1999
• Issued: 03/06/2001
• Est. Priority Date: 03/18/1999
• Status: Expired due to Term

• Current Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Original Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Inventors: Vassiliev, Vladislav
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): KILDAY, LISA A
• Application Number:
  US09/270,598
• Time in Patent Office: 719 Days
• Field of Search: 438/788, 438/789, 438/790, 438/778
• US Class Current: 438/789
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: H01L 21/02131 the material being halogen doped silicon oxides, e.g. FSG
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/31612 on a silicon body

Abstract

A method for fabricating a silicon oxide and silicon glass layers at low temperature using soft power-optimized Plasma-Activated CVD with a TEOS-ozone-oxygen reaction gas mixture (TEOS O₃/O₂ PACVD) is described. It combines advantages of both low temperature Plasma-Enhanced Chemical Vapor Deposition (PECVD) and TEOS-ozone Sub-Atmospheric Chemical Vapor Deposition (SACVD) and yields a coating of silicon oxide with stable and high deposition rate, no surface sensitivity, good film properties, conformal step coverage and good gap-fill. Key features of the invention'"'"'s O₃/O₂ PACVD process are: a plasma is maintain throughout the entire deposition step in a parallel plate type reactor chamber, the precise RF plasma density, ozone concentration in oxygen and the deposition temperature. These features provide the reaction conditions for the proper O₃/O₂ reaction mechanism that deposits a conformal silicon oxide layer. The process has significant implication for semiconductor device manufacturing involving the deposition of a dielectric over a conducting non-planar surface.

Claims

1. A method of forming a silicon oxide film over a heated substrate by a Plasma Activated chemical vapor deposition (PACVD) using TEOS and an ozone source as reactants in the constant presence of a plasma;

the method comprising the steps of;

a) placing a substrate in a parallel plate type reactor chamber;

said substrate has an upper surface with a plurality of steps;

b) in a deposition step, inducing a reaction in a gaseous mixture composition to produce deposition of a silicon oxide film over said substrate, said silicon oxide film is deposited by subjecting said substrate to a plasma during all of said deposition step and wherein said composition comprises tetraethoxysilane (TEOS) a source of ozone, and fluorotriethoxysilane; and

wherein after said deposition of said silicon oxide film, a corner in said silicon oxide film between said steps is avoided.

2. The method of claim 1 wherein said reaction occurs under the following conditions:

a frequency of energy of reaction chamber to produce said plasma is between about 400 KHz and 1356 Khz; and

said plasma has a plasma density in the range of between about 0.05 and 0.5 W/cm²; and

said source of ozone is a O₃/O₂ mixture with an Ozone concentration in oxygen between 10 and 13 wt % and said O₃/O₂ mixture has a flow rate between 3000 and 6000 SCCM; and

at a temperature of said substrate between about 300 and 500°

C.

3. The method of claim 1 wherein said reaction occurs under the following conditions:

a Wafer temperature between 300 and 500°

C., a Pressure between 0.2 and 20 torr, a Plasma density between 0.05 and 0.5 W/cm², a Plasma frequency between 400 and 1356 KHz,

said source of ozone is a O₃/O₂ mixture with an Ozone concentration in oxygen between 10 and 13 wt % and said O₃/O₂ mixture has a flow rate between 3000 and 6000 SCCM; and

He Carrier gas flow between 1000 and 6000 sccm; and

a Wafer spacing between 200 and 600 mils.

4. The method of claim 1 wherein said reaction occurs at the following conditions:

a Wafer temperature between 380 and 440°

C., a pressure between 6 and 14 torr;

a Plasma density between 0.1 and 0.3 W/cm²;

a Plasma frequency between 1350 and 1360 KHz;

a TEOS flow between 300 and 600 mgm;

said source of ozone is a O₃/O₂ mixture with an Ozone concentration in oxygen between 10 and 13 wt % and said O₃/O₂ mixture has a flow rate between 3000 and 6000 SCCM;

a He Carrier gas flow between 1500 and 3000 sccm;

a Wafer spacing between 230 and 300 mils.

5. The method of claim 1 wherein said prior to said deposition step;

performing insitu an oxide liner step to form on oxide liner over said substrate and then performing said deposition step to deposit said silicon oxide film over said oxide liner.