INTRODUCTION TO THE HYBRID PLASMA EQUIPMENT MODEL

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1 INTRODUCTION TO THE HYBRID PLASMA EQUIPMENT MODEL Prof. Mark J. Kushner Department of Electrical and Computer Engineering 1406 W. Green St. Urbana, IL January 1999 ODP04

2 COMPUTATIONAL OPTICAL AND DISCHARGE PHYSICS GROUP at Urbana/Champaign The Computational Optical and Discharge Physics Group (CODPG) at the develops computer simulations and computer aided design tools for low temperature plasma processes and equipment. Plasma materials processing for microelectronics fabrication Plasma remediation of toxic gases Pulsed Power Lighting sources and plasma display panels Lasers and laser-materials interactions These physics based, design capable models are jointly developed and validated with industrial collaborators. The models may be delivered and licensed to our collaborators. ODP01 Optical and Discharge Physics

3 HYBRID PLASMA EQUIPMENT MODEL (HPEM) The Hybrid Plasma Equipment Model (HPEM) is a comprehensive modeling platform developed by the CODPG for low pressure (< 10 s Torr) plasma processing reactors. The HPEM is capable of addressing: ODP02 Inductively Coupled Plasma (ICP) tools. Reactive Ion Etchers (RIE) Electron Cyclotron Resononance (ECR) sources Magnetron sputter and Ionized Metal Physical Vapor Deposition (IMPVD) Remote Plasma Activated Chemical Vapor Deposition (RPACVD) Dust particle transport in plasma tools There are 2-d and 3-d versions of the HPEM. The HPEM is linked to profile simulators developed in the CODPG which predict the evolution of submicron features. The HPEM is now in use at 10 major semiconductor chip and plasma equipment manufactures. Optical and Discharge Physics

4 SCHEMATIC OF THE HYBRID PLASMA EQUIPMENT MODEL Es(r,θ,z,φ) v(r,θ,z) S(r,θ,z) PLASMA CHEMISTRY MONTE CARLO SIMULATION FLUXES ETCH PROFILE = 2-D ONLY = 2-D and 3-D I,V (coils) MAGNETO- STATICS CIRCUIT E ELECTRO- MAGNETICS FDTD MICROWAVE Bs(r,θ,z) E(r,θ,z,φ), B(r,θ,z,φ) ELECTRON MONTE CARLO SIMULATION ELECTRON BEAM ELECTRON ENERGY EQN./ BOLTZMANN NON- COLLISIONAL HEATING Es(r,θ,z,φ) N(r,θ,z) S(r,θ,z), Te(r,θ,z) µ(r,θ,z) FLUID- KINETICS SIMULATION HYDRO- DYNAMICS ENERGY EQUATIONS SHEATH LONG MEAN FREE PATH (SPUTTER) SIMPLE CIRCUIT Φ(r,θ,z,φ) V(rf), V(dc) Φ(r,θ,z) R(r,θ,z) Φ(r,θ,z) R(r,θ,z) EXTERNAL CIRCUIT MESO- SCALE SURFACE CHEMISTRY J(r,θ,z,φ) I(coils), σ(r,θ,z) VPEM: SENSORS, CONTROLLER, ACTUATORS PEUG9904 Optical and Discharge Physics

5 Example: HPEM SIMULATION OF p-si ETCHING The HPEM has been applied to analysis of a large variety of plasma etching systems. Here we show the electron density in an Inductively Coupled Plasma p-si etching tool and the resulting etch profile. Electron Density (1011 cm-3) 40 Coils Photoresist 30 Inlet p-si ODPM01 10 Wafer 0 0 Pump Port Radius (cm) SiO2 Gas Mixture: Cl 2 /Ar = 96/4 Pressure: 4 mtorr Gas flow rate: 30 sccm ICP power: 1000 W Bias voltage: 100 V UNIVERSITY OF ILLINOIS OPTICAL AND DISCHARGE PHYSICS

6 Example: MICROWAVE ECR PLASMA SOURCE A Finite Difference Time Domain (FDTD) module has been developed for the HPEM to address microwave excitation of plasma sources. Here we show the plasma conductiviity and microwave field intensity (2.45 GHz) in an Electron Cyclotron Resonance (ECR) reactor. The injected mode is TE01. Conductivity 30 (1 / Ω-cm) WINDOW 5.0 x 10-2 COILS Azimuthal Electric Field (V / cm) 2.0 x x WAFER 0 SUBSTRATE 20 Radius (cm) 0.0 ODPM02 N2, 750 Watts, 1 mtorr, 10 sccm UNIVERSITY OF ILLINOIS OPTICAL AND DISCHARGE PHYSICS

7 Example: IMPVD OF Al Ionized Metal Physical Vapor Deposition (IMPVD) combines magnetron sputtering with an ICP plasma to produce ionized metal fluxes to the wafer. Ion Flux Al + Density The HPEM addresses both plasma transport and "sputtering physics". Ion and radical energies and angles to all surfaces are produced. Angle of Al + to Target Ar 20 mtorr, -200 V dc, 2 MHz ICP 1.25 kw, 40 V 10 MHz bias Optical and Discharge Physics ODP05

8 Example of HPEM-3D: AZIMUTHALLY ASYMMETRIC POWER DEPOSITION HPEM-3D has been applied to analysis of transmission-line effects in ICP reactors which produce azimuthally asymmetric power deposition. Power deposition: 18.5 Max = 0.92 W-cm-3 (2 decades) FEED SHOWERHEAD NOZZLE QUARTZ COIL FEED PUMP PORT FOCUS RING SUBSTRATE WAFER RADIUS (cm) ODPM MHz, 100 nf termination, Cl2, 10 mtorr, 400 W UNIV. OF ILLINOIS CODP GROUP

9 Example of DTS: NOZZLE GENERATED DUST PARTICLE TRAPS The Dust Transport Simulator (DTS) uses results from the HPEM to follow trajectories of dust particles in plasma tools. HPEM-3D was used to model an ICP reactor having 4 nozzles and a size load lock bay. Top view of particle positions The DTS predicts that dust particle traps are produced by these structures COIL HOUSING WINDOW 8.5 LOAD LOCK BAY FOCUS RING WAFER NOZZLE SUBSTRATE RADIUS (cm) Plasma Tool Geometry ODPM05 Ar, 10 mtorr, 100 W UNIVERSITY OF ILLINOIS OPTICAL AND DISCHARGE PHYSICS

10 COMPUTATIONAL OPTICAL AND DISCHARGE PHYSICS GROUP Contact Information Prof. Mark J. Kushner Department of Electrical and Computer Engineering 1406 W. Green St. Urbana, IL Voice: FAX: ODP03 Optical and Discharge Physics