Apparatus for flash vaporization delivery of reagents

• US 5,536,323 A
• Filed: 07/25/1994
• Issued: 07/16/1996
• Est. Priority Date: 07/06/1990
• Status: Expired due to Term

• Current Assignee: Entegris Incorporated
• Original Assignee: Advanced Technology Materials, Inc. (Entegris Incorporated)
• Inventors: Zhang, Jiming, Buskirk, Peter V., Gardiner, Robin A., Kirlin, Peter S., Binder, Robin L., Stauf, Gregory
• Primary Examiner(s): BUEKER, RICHARD R
• Application Number:
  US08/280,143
• Time in Patent Office: 722 Days
• Field of Search: 118/726, 261/154, 261/100, 261/106, 261/107, 261/104, 261/DIG. 65, 392/399
• US Class Current: 118/726
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/40 Oxides
• CPC Class Codes: C23C 16/408 of copper or solid solutions thereof
• CPC Class Codes: C23C 16/409 of the type ABO3 with A representing alkali, alkaline earth metal or lead and B representing a refractory metal, nickel, scandium or a lanthanide
• CPC Class Codes: C23C 16/4481 by evaporation using carrier gas in contact with the source material C23C16/4486 takes precedence
• CPC Class Codes: C23C 16/4483 using a porous body
• CPC Class Codes: C23C 16/45561 Gas plumbing upstream of the reaction chamber
• CPC Class Codes: H10N 60/0464 by metalloorganic chemical vapour deposition [MOCVD]
• CPC Class Codes: Y10S 261/65 Vaporizers
• CPC Class Codes: Y10S 261/88 Aroma dispensers

Abstract

A process and apparatus for delivering an involatile reagent in gaseous form, wherein an involatile reagent source liquid is flash vaporized on a vaporization matrix structure at elevated temperature. A carrier gas may be flowed past the flash vaporzation matrix structure to yield a carrier gas mixture containing the flash vaporized source reagent. The matrix structure preferably has a high surface-to-volume ratio, and may sutiably comprise a foraminous matrix element such as screen mesh onto which the reagent source liquid is distributed for flash vaporization. The invention is particularly useful for delivery of Group II reagents and compounds and complexes of early transition metals such as zirconium and hafnium, and may be usefully employed with Group II beta-diketonate source layers, e.g., of YBaCuO, BiSrCaCuO, and TlBaCaCuO types, as well as for forming interlayers of Group II metal fluorides between superconductor or gallium arsenide overlayers, and for depositing thin films of photonic and ferroelectric materials, e.g., BaTiO₃, Ba_x Sr_1-x Nb₂ O₆, and PbZr_1-x Ti_x O₃.

Claims

1. A liquid delivery system for delivery of an initially liquid reagent in vaporized form to a chemical vapor deposition reactor arranged in vapor-receiving relationship to the liquid delivery system, said liquid delivery system comprising:

(a) an elongate fluid flow passage defining a longitudinal axis and bounded by an enclosing wall to define a cross-section of the fluid flow passage transverse to the longitudinal axis;

(b) a thin flat porous vaporization element,

(i) having pores in the range of 2 to 200 micrometers,

(ii) having a surface to volume ratio of at least 4, and

(iii) positioned in the fluid flow passage transverse to the longitudinal axis and extending over the cross-section of the fluid flow passage to an outer periphery at the enclosing wall;

(c) means for heating the thin flat porous vaporization element to elevated temperature for vaporization of said liquid reagent;

(d) passage means for delivering a stream of said liquid reagent onto the surface of said porous vaporization element so that the reagent liquid wets the surface of the porous vaporization element in a thin layer of the liquid reagent and is vaporized on said surface when heated by said heating means (c); and

(e) means for discharging vapor formed by vaporization of reagent liquid on the porous vaporization element, from the fluid flow passage for passage to the chemical vapor deposition reactor.

2. A liquid delivery system according to claim 1, wherein the passage means for delivering a stream of said liquid reagent onto the surface of said porous vaporization element comprise a liquid reagent delivery conduit longitudinally extending along the elongate fluid flow passage and terminating at the surface of the porous vaporization element.

3. A liquid delivery system according to claim 1, wherein the porous vaporization element comprises a sintered disk formed of a material selected from the group consisting of metal, glass and ceramics.

4. Apparatus for forming films or layers on a substrate from a source reagent vapor derived from an initially liquid reagent, comprising:

a chemical vapor deposition reactor; and

a liquid deliver system arranged in vapor feeding relationship to the chemical vapor deposition reactor, for delivery of the initially liquid reagent in vaporized form to the chemical vapor deposition reactor.

said liquid delivery system comprising;

(a) an elongate fluid flow passage defining a longitudinal axis and bounded by an enclosing wall to define a cross-section of the fluid flow passage transverse to the longitudinal axis;

(b) a thin flat porous vaporization element,

(i) having pores in the range of 2 to 200 micrometers,

(ii) having a surface to volume ratio of at least 4, and

(iii) positioned in the fluid flow passage transverse to the longitudinal axis and extending over the cross-section of the fluid flow passage to an outer periphery at the enclosing wall;

(c) means for heating the thin flat porous vaporization element to elevated temperature for vaporization of said liquid reagent;

(d) passage means for delivering a stream of said liquid reagent onto the surface of said porous vaporization element so that the reagent liquid wets the surface of the porous vaporization element in a thin layer of the liquid reagent and is vaporized on said surface when heated by said heating means (c); and

(e) means for discharging vapor formed by vaporization of reagent liquid on the porous vaporization element, from the fluid flow passage for passage to the chemical vapor deposition reactor.