Method and device for introducing precursors into chamber for chemical vapor deposition

• US 5,945,162 A
• Filed: 06/17/1996
• Issued: 08/31/1999
• Est. Priority Date: 07/12/1993
• Status: Expired due to Term

• Current Assignee: Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique
• Inventors: Thomas, Olivier, Senateur, Jean-Pierre, Abrutis, Adulfas, Weiss, Francois, Madar, Roland
• Primary Examiner(s): Lusignan, Michael
• Assistant Examiner(s): CHEN, BRET P
• Application Number:
  US08/583,090
• Time in Patent Office: 1,170 Days
• Field of Search: 427/248.1, 427/255.1, 118/726, 118/728, 118/725
• US Class Current: 427/248.1
• CPC Class Codes: B01D 1/18 to obtain dry solids B01D1/24 takes precedence
• CPC Class Codes: C23C 16/4486 by producing an aerosol and subsequent evaporation of the droplets or particles

Abstract

A method is disclosed for introducing into a chemical vapor deposition chamber precursors of elements to be deposited over a heated substrate. The method comprises the steps of maintaining one or more precursors in liquid form or in solution at a pressure higher than the pressure of the chamber; injecting periodically and under control in the deposition chamber precursor droplets each of the droplets having a controllable volume; volatizing the injected precursor droplets to produce evaporated precursors, and conveying toward the substrate the evaporated precursors at a temperature and pressure of the chamber, whereby the evaporated precursors react to produce the elements deposited onto the substrate. A device for performing the same is also disclosed and includes at least one tank containing precursors in liquid form or in solution; means for maintaining each tank at a pressure higher than the pressure of the chamber; at least one controlled injector associated with each tank and provided with control means for periodically injecting controlled amounts of precursor droplets into the deposition chamber; means for volatizing said injected precursor droplets to produce evaporated precursors, and means for conveying the evaporated precursors to the substrate disposed in the deposition chamber.

Claims

1. A method for introducing into a chemical vapor deposition chamber precursors of elements to be deposited over a heated substrate by means of chemical vapor deposition, said method comprising the following steps:

maintaining one or more of said precursors in liquid form or in solution in a solvent at a pressure higher than the pressure of the chamber, periodically injecting a constant amount of said precursors in the form of droplets into the deposition chamber to control the growth rate of elements deposited on said heated substrate, wherein each of said droplets has a duplicable volume,

introducing a counter-path gas flow into said chamber for evacuating evaporated solvent portions of said droplets to reduce the amount of vapor solvent;

volatizing said periodically injected precursor droplets to produce evaporated precursors, and

conveying toward said heated substrate said evaporated precursors at a temperature and pressure of the chamber, whereby said evaporated precursors react to produce said elements deposited onto said heated substrate.

2. The method of claim 1, wherein said step of volatizing further includes:

projecting the injected precursor droplets against a heated plate.

3. The method of claim 1, wherein the size of said droplets is controlled and duplicated by an injector.

4. A device for introducing into a chemical vapor deposition chamber precursors of one or more elements to be deposited on a heated substrate disposed in the chamber, including:

at least one tank containing one or more said precursors in liquid form or in solution in a solvent, said solvent having a higher volatility than said precursors,

means for maintaining each said tank at a pressure higher than the pressure of the chamber,

at least one injector associated with each said tank, each said injector provided with control means for controlling the amount of said precursors to be introduced into said deposition chamber by periodically injecting a constant amount of said precursors in the form of droplets into the deposition chamber, each of said droplets having a duplicable volume, wherein the growth rate of said elements on said heated substrate are controlled,

counter-flow means for introducing a counter-path gas flow into said chamber for evacuating evaporated solvent portions of said droplets to reduce the amount of vapor solvent;

means for volatizing said injected precursor droplets to produce evaporated precursors, and

means for conveying the evaporated precursors to the heated substrate disposed in the deposition chamber.

5. The device of claim 4, further including a heated substrate holder.

6. The device of claim 4, wherein the deposition chamber includes a heated plate on which the injected precursor droplets are projected.

7. The device of claim 4, wherein the deposition chamber is partitioned into two portions by a porous material.

8. The device of claim 4, wherein the deposition chamber is partitioned into a first portion comprising an evaporator and a second portion comprising a reactor maintained at a higher temperature than the first portion.

9. The device of claim 7, including mechanical means for receiving the injected droplets and for conveying them toward the deposition chamber, wherein the mechanical means comprise a conveyor band.

10. The device of claim 4, wherein the size of said droplets is controlled and duplicated by said injector.

11. A device for introducing into a chemical vapor deposition chamber partitioned into a first portion comprising an evaporator and a second portion comprising a reactor maintained at a higher temperature than the first portion, precursors of one or more elements to be deposited on a heated substrate disposed in the chamber, comprising:

a tank containing one or more said precursors in liquid form or in solution in a solvent, said solvent having a higher volatility than said precursors,

means for maintaining said tank at a pressure higher than the pressure of the chamber,

an injector associated with said tank, said injector provided with control means for controlling the amount of precursors to be introduced into the deposition chamber by periodically injecting a constant amount of said precursors in the form of droplets into the deposition chamber in a direction toward said heated substrate, each of said droplets having a duplicable volume, whereby the growth rate of said elements on said heated substrate are controlled,

a second injector for injecting a counter-flow carrier gas having a flow counter to the flow of said droplets toward said heated substrate, and a second carrier gas having a flow toward said substrate, said counter-flow carrier gas and said second carrier gas injected at an intermediate location between said injector associated with said tank and said substrate, wherein said counter-flow carrier gas evacuates evaporated solvent portions of said droplets away from said substrate through a gas vent, and

means for volatizing said injected precursor droplets to produce evaporated precursors, wherein said second carrier gas conveys said evaporated precursors toward said substrate.