plasma原理[共82页]

1、等离子技术讲座: 等离子原理及其应用 PLASMA TRAINING PROGRAM,目录 Agenda,等离子技术在高级封装工业的应用 Application of Plasma Technology in Advanced Packaging Industries. 等离子技术简介 Introduction to Plasma Technology March公司产品介绍 Products of March Plasma Systems,等离子技术在高级封装工业的应用 Plasma Application in Advanced Packaging Industries,综述 Overvi

2、ew,微电子工业 Microelectronic Industry Flash, EEPROM DRAM, SRAM Analog/Linear Microcontrollers, Microprocessors, Microperipherals ASIC 光电子工业 Optoelectronic Industry Laser Diodes Fiber Assembly Hermetic Packaging MEMS 印刷电路工业 Printed Circuit Industry Printed Circuit Board,集成电路封装面临的挑战IC Assembly and Packagi

3、ng: Specific Challenges,不良的芯片粘结 Poor Die Attach Insufficient Heat Dissipation Due to Poor Die Attach 不良的导线连接强度 Poor Wire Bond Strength Contamination on Bond Pad 覆晶填料 Flip Chip Underfill Fillet Height of Underfill Void in Flip Chip Underfill 剥离 Delamination Laminate Materials Releasing Moisture Metal

4、 Leadframe Oxidation 印刷电路板孔中的残余物 Smearing in Printed Circuit Boards 打印记号 Marking,等离子体应用Plasma Applications,表面污染物去除 Contamination Removal Wire Bonding Encapsulation Ball Attach (Contamination Sources: Fluorine, Nickel Hydroxide, Photoresist, Epoxy Paste, Organic Solvent Residue, smear in PCB, and scu

5、m) 表面活化 Surface Activation Die Attach Encapsulation Flip Chip Underfill Marking 表面改性和刻蚀 Surface Modification and Etch Fluxless Soldering Cladding layer removal on fiber,表面活化: 芯片粘结Surface Activation: Die Attach,Proper Die Attach Critical Heat Dissipation Delamination Plasma Treatment of Substrate Pri

6、or to Die Attach Promotes Adhesion of Epoxy Removes Oxidation For Good Solder Reflow Better Bond Between Die and Substrate Better Heat Dissipation Minimizes Delamination,污染物去除: 导线连接Contamination Removal: Wire Bonding,Poor Wire Bond Strength Contamination Oxidation Smaller Bond Pad Pitches 80 mm to 2

7、5 mm Higher Ratio of Contamination to Pad and Wire Deformation Welding Inhibited By Physical Process: Contaminants Act As Physical Barrier Chemical Process: Contaminants Form Bonds With Surfaces and Minimize Adhesion Epoxy Resin Bleedout,污染物去除: 导线连接Contamination Removal: Wire Bonding,Plasma Processi

8、ng Removes Trace Contamination and Oxidation From Substrates Metal Ceramic Plastic Wire Bond Strength Significantly Increased Throughput Increased: Lower Pressure Required,污染物去除和表面活化: 封装Contamination Removal and Surface Activation: Encapsulation,Molding Compound Must Adhere To Different Compounds Su

9、bstrate Material Solder Mask Die Metal Bond Pads Several Materials Bonding to One Another Delamination Can Result From Poor Surface Activity and Contamination,Delamination Biggest Challenge For Organic Based Substrates Laminate Materials Absorb Water From Air and the Flux Residue Removal Process Tra

10、pped Moisture Released From High Temperatures: Use or Soldering Oxidation on Metal Leadframes Can Inhibit Adhesion of Frame to Mold Plasma Treatment of BGA Packages, Other Polymer Substrates, and Metal Leadframes Improves Surface Activity Achieves Good Adhesion Minimizes Delamination,污染物去除和表面活化: 封装C

11、ontamination Removal and Surface Activation: Encapsulation,表面活化: 填料Surface Activation: Underfill,Underfill Required in Flip Chip Minimize Thermal Coefficient of Expansion (CTE) Mismatch Between Die and Substrate Challenge Void Free Wicking Speed Difficult with Large Dies and High Density Ball Placem

12、ent Plasma Treatment Increases Surface Energy Promotes Adhesion Increasing Wicking Speeds Decreased Voiding,Presence of Oxides Inhibits Wire Bonding Limits Good Die Attachment Inhibits Solder Reflow Plasma Treatment Reduces Metal Oxides Improves Wire Bond Strength Improves Die Attachment Improves So

13、lder Reflow,氧化物去除Oxides Removal,印刷线路板上的残余物清除Desmearing in PCB,Smearing in Printed Circuit Boards (PCB) Vias Mechanically or Laser Drilled Laminate Material (Epoxy Resin) Is Smeared Over Edges Of Inner Metal Conductor Lines Subsequent Plating Of The Vias Must Electrically Connect All The Conductor Li

14、nes Smeared Resin Must Be Removed To Ensure Good Electrical Contact Plasma Treatment Removes the Epoxy Resins Producing Carbon Dioxide and Water,集成电路封装中等离子工艺的应用IC Assembly and Packaging: Plasma Solutions,Improves Die Attach Improved Wire Bond Strength With Minimal Process Requirements Effective Enca

15、psulation of Metal and Organic Based Packages Minimizes Voids in Flip Chip Underfill Desmearing in Printed Circuit Boards,等离子工艺的其它应用Other Plasma Applications,Surface Activation of Numerous Materials: Polymers, and Metals 材料表面的活化 Thin Film Etch: Al, Si, SiO2, Si3N4, W, WSix Organic Removal去除有机污染物 Oxi

16、de Removal去除氧化物 Residual Fluorine Removal去除氟的残物 Hydrophilation Hydrophobation Plasma polymerization PECVD,关键参数Critical Product Parameters,Product Type 处理方式 Metal vs. Laminate Chemical Sensitivity Temperature Sensitivity Product Handling 产品放置 Magazine Single Strip Process Required 工艺的要求 Contamination

17、 Removal Surface Activation Throughput 产量的要求 Uniformity 均匀性要求,等离子工艺参数Parameters For Plasma Processing,Power Supply Frequency and Power 电源的功率和频率 Chamber and Electrode Configuration 腔体的结构 Pressure气压 Gas and Concentration工艺气体的选择 Time处理的时间 Pumping Speed 真空泵的速度 Product Positioning产品的位置 Parameters Functio

18、n of Product Type,单一工艺不适合所有的应用 Single Process Will Not Work For All Applications 等离子技术及集成电路封装工艺的知识是成功应用的关键 Knowledge Of IC Package and Plasma Technology Critical For Successful Application MARCH拥有等离子应用的专家解决你的问题 March Maintains Experts Trained In Plasma Technology To Solve Your Problem,March,等离子技术 Pl

19、asma Technology,等离子体简述 Plasma: What, Why, How,什么是等离子体 What? Gas Phase Mixture Consists of: Neutral, Physically Active and Chemically Reactive Species 如何工作 How? By Physical Bombardment and Chemical Reaction to Remove Contamination Activate Surface Etch 为什么要用等离子体技术 Why? Improves Yields and Enhances Re

20、liability of IC Packages Improves Adhesion of Wire Bonds, Die Attach, and Molding Ease of Use, Environmentally Benign, Low CoO,什么是等离子体What is a Plasma,Fourth State of Matter,固态 液态 气态 等离子态 Solid Liquid Gas Plasma Energy Energy Energy,什么是等离子体What is a Plasma,等离子体的组成Components of a Plasma,电子 Electrons

21、离子 Ions Positive Ar + e- Ar+ + 2e- Negative Cl2 + 2e- 2Cl- 自由基 Free Radicals: CH4 + e- .CH3 + .H + e- 光子 Photons Ar + e- Ar* + e- Ar + e- + hn 中性粒子 Neutrals,等离子体特性Plasma Properties,高能量态 High Energy State Physical Work Chemical Work 电中性的 Electrically Neutral Equal Numbers Of Positive and Negative Spe

22、cies Degree of Dissociation = 0.1 - 0.01% Electrically Conductive,表面反应机理: 物理反应Surface Reaction Mechanisms: Physical,Physical Sputtering - Argon Plasma Substrate Placed on (-) Electrode Ar+ Ion Attracted to (-) Electrode Impact Force Removes Contamination Advantages Non-Chemical Reaction: No Oxidatio

23、n Pure Substrate Remaining Disadvantages - Easy to Minimize Substrate Damage: Impact, and Overheating Poor Selectivity Low Etch Rate Contaminant Redeposition,表面反应机理: 化学反应Surface Reaction Mechanisms: Chemical,Plasma Generated Reactive Chemical Species Source Chemicals Include: H2, O2 and CF4 Ionized

24、Source Chemical Produces Reactive Species Gas Phase Products Produced From Reactions with Substrate Surface Advantages High Cleaning Speed High Selectivity Effective for Organic Contaminants Disadvantages - Oxides Can Be Produced,表面反应总结Summary of Surface Reaction Mechanisms,等离子技术的优点Advantages of Pla

25、sma Treatment,Very Effective for Surface Cleaning, Activation, and Etching Environmentally Friendly - Low Gas Flow Non-Hazardous 非危险 No Aqueous Chemicals Used No Personnel Exposure to Chemicals Three Dimensional Treatment Capability(3D处理) Controllable Low Cost Of Ownership Minimal Maintenance Ease o

26、f Use - Automated High Uniformity and Reproducibility,等离子工艺Plasma Process,气相-固相表面相互作用 Gas Phase - Solid Phase Interaction Physical and Chemical 分子级污染物去除 Molecular Level Removal of Contaminants 30 to 300 Angstroms 可去除污染物包括 Contaminants Removed 难去除污染物包括 Difficult Contaminants Finger Prints Flux Gross

27、Contaminants,Oxides Epoxy Solder Mask,Organic Residue Photoresist Metal Salts (Nickel Hydroxide,等离子体的产生Generating a Plasma,等离子体的产生Generating a Plasma,Gas To Be Ionized Chamber With Electrodes Materials Aluminum Stainless Steel Glass: Quartz, Pyrex Configuration Barrel Cylindrical Usually Glass Exter

28、nal Electrodes Parallel Plate Box Internal Electrodes: Powered, Grounded, or Floating Custom,等离子体的产生Generating a Plasma,Vacuum Pump MilliTorr Process Requirements (50mTorr - 500 mTorr) Rapidly Remove Byproducts Rotary Vane Pump Roots Blower Power Supply Energy Source Various Frequencies 2.45 GHz 13.

29、56 MHz 40 kHz DC Various Powers,等离子体的重要特性Important Properties of a Plasma,等离子工艺优化 Effective Plasma Processing Requires Optimum: Physical Processes Chemical Processes 等离子工艺参数 Plasma Properties That Dictate Process Performance: Ion Density Ion Energy DC Bias,等离子体的电子和离子特性Plasma Electron and Ion Propert

30、ies,离子密度 Ion Density Number of Ions per Unit Volume Typically 1 Ion per 10,000 Neutrals 100 Radicals per 10,000 Neutrals Higher Ion Density = Higher Number of Reactive Species High Number of Active Species = Increased Speed, and Uniformity Requires Efficient Coupling of Power,等离子体的电子和离子特性Plasma Elec

31、tron and Ion Properties,离子能量 Ion Energy Energy of Ion To Do Work = Sputtering Sputtering Charged Species Collides With Surface Energy Sufficient To Break Bonds Surface Material Released Narrow Range Excess Ion Energy = Unwanted Sputtering Too Low Ion Energy = No Sputtering or Slow Process,等离子体的电子和离子

32、特性Plasma Electron and Ion Properties,直流偏压 Self DC Bias Negative DC Bias At Power Electrode Capacitively Coupled Electrons Respond to Alternating Electrical Field Capacitor Prevents Electron Flow At Power Electrode Electrons At Ground Electrode Flow To Ground Potential Electron Build Up At Electrode

33、Causes Potential Difference Between Powered and Ground Electrodes = Self DC Bias DC Bias Increases Ion Energy Directionality of Ions Important Parameters: Pressure, Power, Process Gas,等离子处理模型Plasma Modes,Direct Sample Placed Directly In Discharge Samples Placed On Ground or Powered Electrodes: Appli

34、cation Dependent Aggressive Downstream (Shielded) Plasma Generated Downstream Of Samples Gas Phase Active Species Directed To Sample Ions Removed Radicals and Photons Perform Work Reactive Ion Etch (RIE) Direct and Anisotropic Samples Placed On Powered Electrode: Self Bias,Direct Plasma: Argon (Ar,D

35、irect Plasma: Oxygen (O2,Downstream: Ion-Free Plasma,Downstream: Ion-Free Plasma,等离子处理模型Plasma Modes,Reactive Ion Etch (RIE) Direct and Anisotropic Samples Placed On Powered Electrode: Self Bias,成功应用的关键参数Critical Parameters For Successful Application,Power Supply Frequency and Power Chamber and Elec

36、trode Configuration Pressure Gas and Concentration Time Pumping Speed Product Positioning Parameters Function of Product Type,电源功率及频率Power Supply Frequency and Power,General Trend: Higher Frequency = Lower Ion Energy Higher Frequency = Higher Ion Density Higher Power Increases Etch Rate Increases Te

37、mperature Power Supplies DC Low Frequency (40 kHz - 100 kHz) Medium Frequency (13.56 MHz) High Frequency (2.45 GHz,为什么选择频率13.56MHz? Frequency: Why 13.56 MHz ,Ion Energy,Ion Density,Power Frequency,DC40-100 kHz13.56 MHz2.45 GHz,真空腔及电极组合Chamber and Electrode Configuration,Barrel External Electrodes No

38、n-Uniform Plasma Parallel Plate Internal Electrodes Polarity Powered Higher Etch Rate, Higher Temperature, Lower Uniformity Ground Lower Etch Rate, Lower Temperature, Higher Uniformity Floating,气体及浓度Gas and Concentration,Argon (Ar) Inert Physical Process: Surface Bombardment Ar + e- Ar+ + 2e- Ar+ +

39、Contaminant Volatile Contaminant Two to Five Nanometers Removed Applications: Oxide Removal, Epoxy Bleedout Oxygen (O2) Chemical Process: Oxidation of Non-Volatile Organics O2 + e- 2O. + e- O. + Organic CO2 + H2O Rate Function of Gas Concentration = High Pressure Can Oxidize Surfaces and Damage Lami

40、nates Minimize With Ar or Ar/O2,气体及浓度Gas and Concentration,Hydrogen (H2) Chemical Process Applications Remove Oxidation On Metals Clean Metals Without Oxidation Carbon Tetrafluoride (CF4) Normally Mixed With Oxygen Chemical Process Free Radicals React = CO2, H2O, and HF Higher Etch Rate = Higher Pre

41、ssure Other Gases: Helium, Nitrogen, Forming Gas, Sulfur Hexafluoride,气体及浓度Gas and Concentration,化学清洗工艺,化学清洗工艺,物理清洗工艺,气体压力Pressure,Average Force Of Gas Molecules On Chamber Wall Chamber Pressure Gas Flow Outgassing Rate Pumping Speed In General Higher Pressures (200 - 800 mTorr) = Chemical Processes

42、 Higher Pressure = Larger Concentration of Reactive Species High Concentration = Faster Etch Rates Lower Pressures (50 - 200 mTorr) = Physical Processes Lower Pressure = Longer Mean Free Path Long Mean Free Path = Higher Energy Of Ions,处理时间Processing Time,Longer Process Time = More Material Removed

43、Balance Process Time With Power: Higher Power = Faster Etch Rate Pressure: Higher Pressure = Faster Etch Rate Gas Type and Concentration Chamber Electrode Configuration Minimize Time = Maximize Throughput,样品位置Product Positioning,Direct Open Placement On Shelves Carrier or Magazine Require Lower Pres

44、sures For Longer Mean Free Paths Easy To Get Reactive Species Into Carrier Chemical Or Physical Process Pitch Is Critical Uniformity Challenges,在清洗盒中处理 Treatment In Magazine,Typical Plasma Condition: Low system pressure (about 100 mTorr) is required. Increase the mean free path Decrease the hot spot

45、s in chamber Pitch should be larger than 6 mm. The open slot on the side wall of magazine is required,真空泵速度Pumping Speed,Pump Required To Maintain Vacuum Sweep Away Plasma Byproducts Minimize Re-contamination,等离子工艺中可能的问题: 温度Plasma Problems: Temperature,Plastic Parts are Susceptible to High Temperatu

46、re Factors That Effect Temperature Substrate Material of Construction Conductive - Metal Leadframes Nonconductive - BGA Placement of Parts on Electrode Ground: Cooler Temperature, Longer Process Times Powered: Hotter Temperature, Shorter Process Times Process Power and Frequency Higher Power = Highe

47、r Temperature Lower Frequency = Higher Temperature 40 kHz 13.56 MHz Process Gas and Gas Flow Higher Gas Flow = Lower Temperature,等离子工艺中可能的问题: 温度 Possible Problems In Plasma: Temperature,Factors That Effect Temperature Process Time Longer Process Time = Higher Temperature Chamber Temperature Typicall

48、y 1250C PX Product Line Has Optional Liquid Cooled Shelves,等离子工艺中可能的问题Possible Problem in Plasma,均匀度 Uniformity Gas Supply and Removal Should Be Uniform Chemical Processes Typically Have Higher Uniformity Longer Mean Free Path - Lower Pressures For Physical Processes Can Help 表面变色 Discoloration Heat

49、 Build Up Complex Parts Can Create Plasma Hot Spots 处理寿命 Treatment Longevity Function Of Substrate Material Humidity Outgassing of Plasticizers and Mold Release Compounds,等离子工艺中可能的问题Possible Problems In Plasma,荷载影响 Loading Effect Materials Outgas Under Vacuum Effects Pump Down Time Base Pressure Dis

50、place Process Gases Amount of Substrate Material in Chamber Effects Process Material Quantity Can Affect Plasma Density Gas Supply Could Be Insufficient 副产品 Byproducts Overtime, CF4 Will Polymerize On Chamber Walls and Can Deposit on The Substrate Surfaces,表面接触角检测Contact Angle Measurements (CAM,Cont

51、act Angle Indicates Surface Energy Characterizes Interfacial Tension Solid - Liquid Drop Low Surface Energy Solid (Hydrophobic) Liquid Surface Tension Solid Surface Energy Liquid Forms Spherical Shape High Surface Energy Solid (Hydrophilic) Liquid Surface Tension Solid Surface Energy Liquid Forms Lo

52、w Profile Flatter Droplet View Droplets Of Liquid On Surface Line Tangent To Curve Of Droplet Angle Between Tangent Line and Solid Surface,March,等离子技术 Plasma Technology (Not All Plasma Systems Are The Same) + 集成电路封装技术 IC Packaging Technology (Not All Packages Are The Same,成功应用 Successful Application

53、 of Plasma Technology for Integrated Circuit Packaging,March 产品 March Products,Batch vs. Automated,Equipment Solutions,AP-1000e8,AP-1000,Batch System Solutions,AP-1000,Flexible Shelf Configuration Complete System Enclosure PLC Controller Vertical Door Option e8 Option CE and SEMI S2-93 Compliant App

54、lications Magazine Treatment Auer Boat Processing Wafer Cleaning MCM Carriers Boards,AP 1000 Vertical Door,Higher throughputs Improved uniformity Matrix/Array Pkgs Metal Leadframes,AP-1000e8,MultiTRAK,ITRAK,Automated System Solutions,XTRAK,Automated System Solutions,Unparalleled Uniformity Compact C

55、hamber Design Balanced Gas Flow Unique Vacuum Exhaust Guaranteed Repeatability Strip by Strip Processing Closed or Open Magazines No Pitch Restrictions Speed Total Overhead Time: Seconds Infeed Vacuum and Plasma Outfeed,Strip Sized Chamber ITRAK Width 38-78 mm Length 178 mm - 235 mm XTRAK Width 16-154 mm Length 76-305 mm PLC Controlled wi