CN201071403Y

CN201071403Y - Upward-in and upward-out vertically spraying type MOCVD reactor

Info

Publication number: CN201071403Y
Application number: CNU2007200400989U
Authority: CN
Inventors: 左然; 徐谦
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2007-06-27
Filing date: 2007-06-27
Publication date: 2008-06-11
Anticipated expiration: 2017-06-27

Abstract

The utility model discloses a vertically-sprinkling MOCVD reactor structure with a top intake and a top exhaust. The reactor structure comprises a reaction chamber, a heating system, a sprinkling head and an inlet and outlet for cooling water. The utility is characterized in that reaction gases are blown into the reaction chamber through a plurality of small nozzle tubes that are arranged compactly; furthermore, tail gases after reaction are exhausted out of a plurality of small exhausts on the top; the intakes and the exhausts are arranged in a crossing manner at the top. Therefore, the utility model enables thel concentration of reaction gases above substrates to alter periodically within a small area near each nozzle tube, therefore greatly reducing the radial non-uniformity of the thickness of film sediment and of the concentration of impurities; moreover, the utility model can also eliminate complicated rotation of the substrates.

Description

A kind of vertical shower type MOCVD reactor that goes out on enterprising

Technical field

The utility model relates to a kind of semiconductor film film deposition apparatus, promptly a kind of vertical shower type MOCVD reactor that goes out on enterprising.Purpose is by the flowing-path of pilot-gas in reactor, and gas flow rate, temperature and the reactant concn that makes substrate top be uniform distribution all, thereby obtains that crystalline network is complete, thickness and the uniform thin film deposition of component.

Background technology

Metal organic chemical vapor deposition, promptly MOCVD (Metalorganic Chemical Vapor Deposition) is a gordian technique of preparation compound semiconductor film.It utilizes than volatile organic matter such as Ga (CH ₃) ₃Source reactant Deng as more difficult evaporable atoms metal is carried in the reactor by carrier gas, with NH ₃, AsH ₃React in hydride, on the substrate of heating, generate films such as GaN, GaAs, be used for microelectronics or photoelectric device.The MOCVD system generally comprises: (1) source supply system; (2) gas transport system; (3) reaction chamber; (4) heating system; (5) exhaust treatment system; (6) Controlling System; (7) wafer clamping and placing system.Usually said MOCVD reactor generally comprises reaction chamber, heating system and inlet mouth and air outlet.According to the relative direction of main air stream and substrate, the MOCVD reactor mainly is divided into two big classes: (1) main air stream along continuous straight runs flows and is parallel to the horizontal reactor that is called of substrate; (2) main air stream vertically flow and the vertical impact substrate be called rectilinear reactor.Two kinds of modern commercial MOCVD reactor-planetary and vertical shower types can be considered as respectively developing from horizontal and rectilinear reactor.

One of important indicator of film preparation is exactly the homogeneity of its thickness and component.In the MOCVD technology, grow the uniform large area film material of thickness and component, the substrate speed of growth and the reactant concn that the arrives substrate uniformity of should trying one's best everywhere.This just requires to have uniform flow field, temperature field and distribution of concentration near the substrate surface, and the substrate top should be in the laminar region, does not have any type of eddy current, and the substrate top has big thermograde, fresh reactant should be able to arrive substrate top each point simultaneously.

In horizontal reactor, to opposite side, this structure of reactor is simple from an effluent of substrate for reactant gases, but has problems such as serious reactant depletion and thermal convection vortex, cause the front and back ununiformity of film thickness easily, need to be overcome with the method for complexity.General adopt two kinds of methods: (1) makes substrate tilt to place with certain angle, or be to back lower place inclination with the top design of reactor, thereby reactant gases is rearward quickened, the consumption of compensatory reaction substrate concentration; (2) make the substrate rotation, purpose is to make the substrate each point can both accept same reacting gas concentration to supply with.The shortcoming of horizontal reactor maximum is to be difficult to deposit the multi-disc wafer simultaneously, so only be used for usually being not suitable for industrial large-scale production in the testing laboratory.

In rectilinear reactor, gas enters from the top of substrate and rolls over to turn 90 degrees and cross substrate, then from the reactor side or the bottom discharge.When the substrate high speed rotating, the fluidic viscous force produces a kind of pump efficiency and answers (Von Karman Pump): because the effect of viscosity, one deck gas near substrate surface rotates together in company with rotating disk, and under action of centrifugal force, gas is constantly radially thrown to the outer rim of substrate.Meanwhile, the gas of substrate top flows into substrate surface vertically to replenish the gas that loses.This pump efficiency should be able to be offset the vortex of thermal convection generation, obtains substrate top boundary layer thickness uniformly, supplies with thereby make substrate top each point obtain uniform particle concentration.The rectilinear reactor of high speed rotating (RDR formula) can depositing high-quality semiconductor film, but this reactor once can only deposit a wafer usually, production efficiency is low.

The vertical shower type reactor is the improved form of rectilinear reactor, and reactant gases directly sprays to substrate by the little jet pipe of the many solid matters in pallet top, thereby makes the reacting gas concentration that arrives substrate top (outside the frictional belt) each point basic identical.Reactant gases passes the frictional belt and arrives substrate surface again by the concentration diffusion.Utilize energy of rotation to access substrate top boundary layer thickness uniformly, thereby obtain the film growth of better quality.This reactor once can deposit a plurality of wafers.But, owing to the reactant gases that sprays into directly over substrate all must flow to tray edge, discharge (going out under enterprising) by the outlet that is arranged in reactor side or bottom again, the reactant gases that sprays in the pallet center is obviously different with the distance that the reactant gases that sprays at the tray edge place is flowed through.The resultant tail gas of center can not in time be discharged, and causes substrate thickness and impurity concentration radially still to have ununiformity.Above-mentioned ununiformity mainly relies on the pallet rotation to solve, but this has increased technology difficulty, control difficulty and the unstable of device.

The relevant patent of the vertical spray header of existing MOCVD reactor, as " in order to the shower nozzle of the chemical vapor depsotition equipment of making semiconductor device " (application number 03120956.4, publication number CN1450598A), " the double-deck gas tip that is used for metal organic chemical vapor deposition equipment " (application number 200410017471.X, publication number CN1563483A), " a kind of horizontal reactor structure that is used for vapour deposition " (application number 200310108793.0, publication number CN1544687) etc., all belong to " going out under enterprising " type.

Summary of the invention

The utility model proposes a kind of novel vertical shower type MOCVD reactor that goes out on enterprising.The outlet of the gas feed of this reactor and reaction back tail gas all above pallet, i.e. the top of reactor.

The MOCVD reactor that the utility model proposes comprises reaction chamber, heating system, spray header and water coolant import and export.Reaction chamber wall adopting quartz glass or stainless steel, heating system adopt induction type or resistance-type heating graphite substrate, and graphite substrate is placed on the pallet.Pallet can not rotate, and can connect ceramic rotating shaft yet, slowly rotates (not needing high speed rotating) by motor drives.It is characterized in that outlet of reacting gas inlet, tail gas and cooling water channel, all on the spray header of reactor head, realize by the aperture and the pipeline of many solid matters of arranging on the spray header.Reactant gases is ejection downwards from substrate top, discharges from the aperture of substrate top again, goes out on promptly enterprising.The inlet mouth and the air outlet of reactor top periodically are staggered, the lattice two-dimensional arrangements of negative ions in the similar ionic crystal.

Be furnished with uniform tubule and aperture on the reactor spray header, tubule is a reacting gas inlet, and aperture is the tail gas outlet, is evenly equipped with four pneumatic outlets around each tubule, outlet area and should more than or equal to intake area and, the gap of air flue also is furnished with cooling water channel.

Reactant gases enters reaction zone from the many parallel little jet pipe ejection of substrate top spray header in the work, and reacted tail gas is discharged from the outlet that is positioned at the substrate top again, i.e. import jet pipe and tail gas outlet is all above substrate.She Ji benefit is like this, by the reactant gases of each little jet pipe ejection, through discharging from the outlet of the top around it again after the reaction, so, the concentration distribution of substrate top each point, is only done periodically to repeat near single jet pipe with the change in location at distance pallet center with no longer.Be that the on a large scale radial undulation of original reactant concn along the pallet center to the edge become along the cyclic fluctuation among a small circle on every side of single jet pipe, the component of substrate growth and thickness evenness will depend on the fluctuation of concentration among a small circle around the single jet pipe.Distance by regulating jet pipe end and substrate, jet pipe spacing, flow velocity, pressure etc. can reach and control film growth component and the uniform purpose of thickness.

The MOCVD reactor that the utility model proposes comprises two types: the reactor that (1) reactant gases pre-mixing enters; (2) two kinds of reactant gasess are separated the reactor that enters.Difference between them is that premixed reactor upper end only needs to separate two kinds of gas flows, i.e. inlet channel and tail gas outlet; And two kinds of reactant gasess are separated the reactor upper end that enters, and need be separated out two kinds of gas feed runners and a kind of tail gas outlet flow.Uniform tubule belongs to two kinds of different reacting gas inlets on this moment top spray head, they with outlet aperture space, be staggered.

The utility model has the advantages that: the thickness of substrate and component ununiformity are radially reduced greatly, grown high-quality film.Also can exempt the high speed rotating of pallet, simplify the structure of reactor.

Description of drawings

The reactor front schematic view that Fig. 1 enters for the reactant gases pre-mixing

Fig. 2 is the spray header upward view of this reactor

Fig. 3 is that two kinds of reactant gasess are separated the reactor front schematic view that enters

Fig. 4 is the spray header upward view of this reactor

The graphite plate of side wall surface 7 heating of 1 import, 2 outlets, 3 jet pipes, 4 reaction chambers, 5 substrates, 6 reactors and stainless steel support 8 ceramic rotating shaft 9 entrance of cooling water 10 cooling water outlets 11 reaction back tail gas general exports.

Embodiment

Further specify apparatus structure of the present utility model and principle of work below in conjunction with accompanying drawing.

As shown in Figure 1 and Figure 2, the reactant gases that is pre-mixed feeds from import 1, sprays into reaction chamber 4 from jet pipe 3, after reactant gases is heated chemical reaction takes place, deposition on substrate 5.Tail gas is discharged from the outlet 2 that is positioned at the substrate top.Because outlet 2 and jet pipe 3 cross arrangements.Uniform four outlets around each jet pipe, therefore for each jet pipe, the influence of sidewall is very little.The flow state of each point above substrate all is the periodicity repetition around single jet pipe.Thereby eliminated the wide variation of reactant concn from the center to the radius.

Shown in Fig. 3,4, gas feed 1A, 1B and tail gas outlet 2 are apart from one another by arrangement, A reactant gases and carrier gas enter from import 1A, B reactant gases and carrier gas enter from import 1B, spray into reaction chamber 4 by jet pipe 3A and the 3B that links to each other in inside respectively, mix and heating back generation chemical reaction, on substrate 5, deposit.Reacted tail gas is discharged from the outlet 2 that is positioned at the substrate top.9 are reaction back tail gas general export.All the other each parts marks and the gas pre-mixed reactor (Fig. 1 and Fig. 2) identical (cooling water channel is not expressed) that enters that closes.

Claims

1. vertical shower type MOCVD reactor that goes out on enterprising, it comprises reaction chamber, heating system, spray header and water coolant import and export; Reaction chamber wall adopting quartz glass or stainless steel, heating system adopt induction type or resistance-type heating graphite substrate, and graphite substrate is placed on the pallet; It is characterized in that: inlet mouth, air outlet and cooling water channel all on the spray header of reactor head, are periodically staggered aperture and pipeline on the spray header.

2. a kind of vertical shower type MOCVD reactor that goes out on enterprising according to claim 1, it is characterized in that: the tubule of arranging on the reactor spray header is the reactant gases inlet mouth, aperture is the tail gas air outlet, be evenly equipped with four pneumatic outlets around each tubule, outlet area and should more than or equal to intake area and, the gap of air flue is furnished with cooling water channel.

3. a kind of vertical shower type MOCVD reactor that goes out on enterprising according to claim 2 is characterized in that: to belong to be two kinds of different reacting gas inlets to uniform tubule on the reactor spray header, they with outlet aperture space, be staggered.