CVD method and apparatus for making silicon oxide films

• US 5,545,436 A
• Filed: 11/04/1994
• Issued: 08/13/1996
• Est. Priority Date: 11/12/1993
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Saito, Masaki
• Primary Examiner(s): King, Roy V.
• Application Number:
  US08/336,054
• Time in Patent Office: 648 Days
• Field of Search: 427/255.3, 427/255.2, 427/255.1, 427/255.5, 427/579, 427/574, 427/248.1, 118/715, 118/729
• US Class Current: 427/255.37
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/45514 Mixing in close vicinity to the substrate
• CPC Class Codes: C23C 16/45519 Inert gas curtains
• CPC Class Codes: C23C 16/45561 Gas plumbing upstream of the reaction chamber
• CPC Class Codes: C23C 16/45595 Atmospheric CVD gas inlets with no enclosed reaction chamber
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/31608 Deposition of SiO2 H01L21/31625, H01L21/31629 and H01L21/31633 take precedence

Abstract

A CVD system for accomplishing deposition of a silicon oxide film on a wafer which is moved in a predetermined direction, under a reaction between an organic Si source and O₃. The CVD system comprises a gas injector having a first slit for ejecting a gas containing O₃, a second slit for ejecting a gas which is inert to a reaction between the organic Si source and O₃, a third slit for ejecting a gas containing the organic Si source, a fourth slit for ejecting a gas which is inert to the reaction, a fifth slit for ejecting a gas containing the organic Si source, a sixth slit for ejecting a gas which is inert to the reaction, and a seventh slit for ejecting a gas containing O₃. Additionally, the first to seventh slits are arranged in the order named in the predetermined wafer moving direction. This CVD system improves the characteristics and quality of silicon oxide film deposited on the wafer while lowering a so-called substrate dependency of the deposited film.

Claims

1. A thermal CVD method for depositing a silicon oxide film on a substrate comprising the steps of:

providing a gas injector for injecting gases toward a surface of a substrate;

moving a substrate in a predetermined direction adjacent the gas injector; and

ejecting the following gases in the order named to a surface of the substrate;

a first gas containing O₃ ;

a second gas which is inert to a reaction between an organic Si source and O₃ ;

a third gas containing the organic Si source;

a fourth gas which is inert to the reaction;

a fifth gas containing the organic Si source;

a sixth gas which is inert to the reaction; and

a seventh gas containing O₃, the flow rate of the second gas being higher than the flow rate of the sixth gas such that deposition of the silicon oxide film proceeds by a postmixing method and thereafter by a pre-mixing method as the substrate is moved in said predetermined direction past said gas injector.

2. A thermal CVD apparatus comprising:

a gas injector for ejecting gases containing an organic Si source and O₃ toward a surface of a substrate, said gas injector having a plurality of linearly adjacent nozzles including;

a first nozzle for ejecting a gas containing O₃ ;

a second nozzle for ejecting a gas which is inert to a reaction between the organic Si source and O₃ ;

a third nozzle for ejecting a gas containing the organic Si source;

a fourth nozzle for ejecting a gas which is inert to the reaction;

a fifth nozzle for ejecting a gas containing the organic Si source;

a sixth nozzle for ejecting a gas which is inert to the reaction; and

a seventh nozzle for ejecting a gas containing O₃ ; and

means for moving a substrate in a predetermined direction with respect to the gas injector from the first nozzle to the seventh nozzle, whereby a silicon oxide film is deposited on the substrate as it moves past the gas injector.

3. A CVD apparatus as claimed in claim 2, wherein said gas injector has an ejection surface which is locatable immediately above and parallel with the surface of said moved substrate, said first to seventh nozzles being opened at said ejection surface to eject gas.

4. A CVD apparatus as claimed in claim 2, wherein said gas containing organic Si source is one selected from the group consisting of TEOS (tetra ethoxy silane), OMCTS (octa methyl cyclotetra siloxane), TPOS (tetra propoxy silane), and TMCTS (tetra methyl cyclo tetra siloxane).

5. A CVD apparatus as claimed in claim 2, wherein said inert gas is N₂ gas.

6. A thermal CVD apparatus as defined in claim 2, further comprising means for setting a flow rate of gas through each nozzle and wherein the flow rate of gas through the second nozzle is higher than the flow rate of gas through the sixth nozzle, such that deposition of the silicon oxide film proceeds by a postmixing method and thereafter by a premixing method as the substrate is moved past the gas injector from the first nozzle to the seventh nozzle.