CVD_Process_Introduction.ppt

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1、CVD Process Introduction,Outline,1.CVD Process Introduction2.CVD Type Classification3.Dielectric Film Characteristic4.CVD film Application-DARC and LowK5.Q&A,2,Outline,1.CVD Process Introduction2.CVD Type Classification3.Dielectric Film Characteristic4.CVD film Application-DARC and LowK5.Q&A,3,1.CVD

2、 Process Introduction,4,CVD(Chemical Vapor Deposition):The process of depositing solid films using gases or vapors via chemical reaction on the substrate surface.,Advantages of CVD:Good step coverage can be achieved Wide range of materials availableGood composition controlGood process control,1.CVD

3、Process Introduction,5,The sequence of reaction steps in a CVD reaction,Diffusion of reaction to surface,Diffusion of products from surface,Film-forming reaction,Subsequent surface reaction,Desorption,Absorption,1.Transport of reacting gaseous species to the substrate surface2.The reactants are adso

4、rbed on the substrate.3.The adatoms undergo migration and film-forming chemical reactions.4.Desorption of gaseous reaction by-products5.Transport of reaction by-products away from the substrate surface,CVD Process Sequence,1.CVD Process Introduction,(I):MASS TRANSPORT LIMITED at higher temperature D

5、eposition rate is sensitive to flux concentration insensitive to temperature(II):SURFACE REACTION RATE LIMITED at lower temperature Deposition rate is sensitive to temperature insensitive to flux concentration,(I),(II),1.CVD Process Introduction,Dep rate vs Temp,Schematic diagrams of transport of re

6、acting gaseous species from source to the substrate surface for(a)surface reaction rate limited reaction,and(b)mass transport limited reaction.,1.CVD Process Introduction,Surface reaction&Mass transport limited,Components of DCVD Systems,1.Gas sources2.Gas feed lines3.Mass flow controller4.Reaction

7、chamber5.Heating and temperature control system6.Pumping and pressure control system7.RF system 8.Exhaust,1.CVD Process Introduction,1.CVD Process Introduction,10,IMD(Inter Metal Dielectric)SiN/SiCN/SiCSiO2/FSG/SiOCH,Passivation:SiO2 SINSiON,BEOL,FEOL,STI(Shallow Trench Isolation)Poly HM(Hard Mask)S

8、pacerSAB(Salicide Block)SMT(Stress Memory Technology)CESL(Contact Etch Stop Layer)PMD(Pre-Metal Dielectric),1.CVD Process Introduction,11,DCVD Process Precursors:Silicon source:TEOS,SiH4,TMSOxygen source:O3,TEOS,N2O,O2Phosphorus source:TEPO,PH3Boron source:TEB,B2H6Fluorine:SiF4,NF3Nitric source:N2,N

9、H3Carbon source:C2H2,C3H6,TMS:(CH3)4Si,四甲基硅烷,TetramethylsilaneTEOS:Si(OC2H5)4,四乙氧基硅烷,Tetraethoxysilane TEPO:PO(OC2H5)3,三乙氧基磷烷,Triethyl PhosphateTEB:B(OC2H5)3,三乙氧基硼烷,Triethyl Borate,SiO2(USG),SiN,SiON,PSG,BPSG,SiCN,SiOC,FSG,Outline,1.CVD Process Introduction2.CVD Type Classification3.Dielectric Film

10、Characteristic4.CVD film Application-DARC and LowK5.Q&A,12,2.CVD Types Classification,13,Temperature basedHTO<O(High&Low Temperature Oxide)RTCVD(Rapid Thermal CVD),Pressure basedLPCVD(Low Pressure)APCVD(Atmospheric Pressure)SACVD(Sub Atmospheric Pressure),Reagent basedSilaneTEOS MOCVD(Metal Organi

11、c),Energy basedThermal CVDPECVD(Plasma Enhanced)HDP(High Density Plasma),2.CVD Types Classification,14,Pro&Con for Some Typical CVD Process,Three popular methods are widely adopted to produce SiO2.1.LPCVD TEOS oxide(Typical spacer oxide)Si(OC2H5)4-SiO2+by-products D.R.:55 A/min.700C2.PECVD TEOS oxid

12、e(Typical IMD oxide)Si(OC2H5)4+O2-SiO2+by-products D.R.:7000 A/min.Plasma(400C)3.SACVD O3/TEOS oxide(Typical IMD oxide)Si(OC2H5)4+O3-SiO2+by-products D.R.:1800 A/min.400C,2.CVD Types Classification,Heating vs Plasma,1.LPCVD Si3N4 depositionNH3+SiH2Cl2-Si3N4+By products D.R.:18 A/min.740C 780C2.PECVD

13、 Si3N4 deposition.(2)SiH4+NH3+N2-SixNyHz+By products D.R.:9000 A/min.400C,2.CVD Types Classification,PECVD NIT,2.CVD Types Classification,17,Plasma,S,Heater Plate,RF Power,Process Gases,Byproduct to The pump,Wafer,Process Chamber,Shower head,SACVD:No RF system,No Plasma,Simple Sketch Map For PECVD&S

14、ACVD Process,2.CVD Types Classification,18,Basic Principle of HDP CVD,2.CVD Types Classification,19,Over Sputtering Sputtering of Metal and ARC Layer at the cornerToo Little SputteringCusping of Deposition Oxide-Poor gap-Filling Results in VoidEquilibrium Between Deposition and Sputtering at the Cor

15、nerDeposition Rate(Dc)=Sputtering Rate(Sc)MAXIMIZED GAPFILL CAPABILITY,2.CVD Types Classification,20,PECVD,HDP CVD,Gapfill Capability Compare,Outline,1.CVD Process Introduction2.CVD Type Classification3.Dielectric Film Characteristic4.CVD film Application-DARC and LowK5.Q&A,21,3.Dielectric Film Char

16、acteristic,22,1.Particle2.Thickness&Uniformity3.Refractive Index-Impurity,composition-Density4.Reflectivity5.Stress6.FTIR-Composition bonding ratio:Si-F,Si-H,Si-N,Si-CH3-Impurity(-H,-OH,H2O)7,XRF-Dopant concentration:B,P,8.Etching Rate-Composition(Dopant level)-Density9.SEM&TEM-Step coverage/Gap fil

17、l-Degree of planarization10.Electrical Properties-Dielectric constant-Dielectric breakdown,3.Dielectric Film Characteristic,23,Non-Uniformity,Range-Uniformity,Uniformity,3.Dielectric Film Characteristic,24,Dep Rate,Shrinkage,After a thermal cycle,film thickness shrinks.The smaller the shrinkage,the

18、better the film quality.,Deposition rate is a very important specification of a CVD process,as it is directly related to throughput.,3.Dielectric Film Characteristic,25,RI can deliver the information for films chemical composition and physical condition.,RI(Refractive Index),3.Dielectric Film Charac

19、teristic,26,Stress,3.Dielectric Film Characteristic,27,R is the calculated radius of curvaturets is the substrate thicknesstf is the film thicknessE is the substrate Yongs modulusv is the substrate Poisson ratio,G.Gerald Stoney.Proc.R.Soc.Lond.A80.172-175(1909),Stress,3.Dielectric Film Characteristi

20、c,28,Step coverage,TEOS,Silane,Outline,1.CVD Process Introduction2.CVD Type Classification3.Dielectric Film Characteristic4.CVD film Application-DARC and LowK5.Q&A,29,4.CVD film Application-DARC,30,DARC(Dielectric Anti Reflective Coating),31,4.CVD film Application-DARC,32,4.CVD film Application-DARC

21、,Why Need Low K?RC Delay,4.CVD film Application-Low K,33,How to do Low K?Porosity,Air is considered the perfect insulator.It has a dielectric constant of 1.One method of creating low-k dielectric materials is to introduce nanometer scale pores into a solid film to lower its effective dielectric constant.,4.CVD film Application-Low K,34,35,Current CVD tools list table in HuaLi,36,Q&A,