KURT J. LESKER LAB 18 SPUTTERING SYSTEM STANDARD OPERATING PROCEDURES

Transcription

1 KURT J. LESKER LAB 18 SPUTTERING SYSTEM STANDARD OPERATING PROCEDURES Version: 1.1 March 2014 UNIVERSITY OF TEXAS AT ARLINGTON Nanofabrication Research and Teaching

2 Facility TABLE OF CONTENTS 1.0 INTRODUCTION SCOPE OF WORK DESCRIPTION SAFETY REQUIREMENTS/RESTRICTIONS SYSTEM REQUIREMENTS/RESTRICTIONS OPERATING PROCEDURES SYSTEM CHECKS SELECTING AND RUNNING A RECIPE MONITORING THE DEPOSITION RECIPES RECIPE RULES AND FUNCTIONALITY RECIPE EDITING INDEX Process Parameters Base Recipe

3 1.0 Introduction 1.1 Scope of Work These procedures apply to the Kurt J Lesker (KJL) Lab 18 sputtering system. All maintenance should follow the procedures set forth in the manufacturer s maintenance and operations manuals. This document is for reference only. Users must be trained by Nanofab staff before operating this system. 1.2 Description The Kurt J Lesker (KJL) Lab 18 Sputtering System uses four shuttered magnetron guns containing 4 X.250 targets to sputter deposit single thin films or multiple stacked film layers on wafers up to 6 diameter, glass slides and small samples. Substrate heating and rotation is also available for enhanced film properties and improved film uniformity. This tool is equipped with one RF power supply for sputtering so only one material can be deposited at a time. Current materials approved for use in the KJL Lab 18 include (Si, SiO 2, Si 3 N 4, HfO 2, TiO 2, and ITO). Due to the fact there are only four magnetron guns all target materials are not readily available at any given time. Contact Nanofab staff for material availability. In addition to the magnetron guns an ion source is also available for the etching of native oxide, deposited materials and for use during deposition to enhance uniformity. Process gases available on this system include Argon, Nitrogen, & Oxygen. 1.3 Safety This machine is connected to HIGH VOLTAGE. Be very careful and aware of electrical hazards. If you encounter any electrical malfunctions contact NanoFab staff immediately This machine uses RF frequency power. DO NOT operate this machine with any RF cables disconnected or any component enclosures/panels open This machine can heat substrates to high temperatures (850C ). Make sure you wait until the substrate temperature is < 50C before transferring your sample to the load lock chamber This machine has water flow interlocks to prevent over heating the substrate heater, turbo pump and magnetron guns. If you encounter any water leaks or water flow alarms notify NanoFab staff immediately This machine has an EMO (Emergency Off) switch/button mounted on the front panel. The EMO shuts off all power to the system when pressed. The EMO switch should be pressed only in an emergency. An emergency would be fire, smoke, electrocution hazards, and an injury to anyone using this particular piece of equipment. If the EMO is pressed notify NanoFab staff immediately. 3

4 1.3.6 This machine uses Ar, N 2, and O 2 gas which in high concentrations can be asphyxiates. The process gases are normally pumped out of the system. If the process pressure is not being maintained or system cannot reach base pressure notify NanoFab staff immediately Read any posted NanoFab Engineering Change Notices (ECN) (Fig. A) for any hardware, process or safety changes before running the tool. 2.0 Requirements/Restrictions (Fig. A) 2.1 System Requirements/Restrictions You must be a qualified user on the KJL Lab 18 Sputtering System The KJL Lab 18 sputter system can be used to deposit Si, SiO 2, Si 3 N 4, HfO 2, TiO 2 & ITO and other approved materials on 1-5 diameter wafers, glass slides, and small samples by using the substrate carrier plate. All 6 diameter wafers can be deposited by installing the wafer directly into the sample carrier without being mounted to the sample plate. Small pieces can be processed by using the wafer holder clips or by bonding to the sample plate with polyimide tape. No substrate heating is allowed if polyimide tape is being used to bond the sample to the plate Personal recipes are created for users by Nanofab staff. Users are only allowed to run and edit their personal recipes The maximum RF power to any RF Gun is 225 Watts The maximum RF power ramp rate is 2 U/S as given in the recipe If you are using the substrate heater be careful not to overheat your wafer/samples to prevent any wafer breakage, metal or any other material to flow The substrate should be < 50C before transferring the sample carrier to the load lock chamber for removal. 4

5 3.0 Operating Procedures 3.1 System Checks Upon approaching the system if the screen is black or if the screen saver is running touch the top center section of the touch screen (Fig. 1) to bring the computer operation screen up. Do not touch any other section of the screen while it is black. Touching another section of the touchscreen could inadvertently actuate a valve or turn a device on/off. (Fig. 1) Check the KJL System Logbook and verify that no other user is running a process before proceeding. If another user is running the system contact the user in question or a staff member to check system availability before proceeding Begin your entry in the System Logbook so other users know you are now using the system Press the LOGIN button in the upper right hand side of the KJL main software screen. Log into the KJL system computer using your assigned Username & Password. If another user is currently logged in then you MUST log that user out and log back in using your own username before proceeding. 5

6 3.1.5 While monitoring the Operation Vacuum screen, verify that the ion gauge filament and emission current are both ON by looking at the upper left hand side of the screen at the subsection titled PC Gauging. In this subsection the FIL ON and Emission Current should both be illuminated green (Fig 2). If either of them is OFF then press the FIL ON button first and wait until the chamber vacuum pressure displays < 1.5 E - 6 before turning ON the Emission Current. (Fig. 2) With the Filament and Emission Current both ON (indicators green) the vacuum pressure as indicated at the bottom of the Operation Vacuum screen (See Fig. 2) should read < 2.0 E -7 within a few minutes. If the pressure is higher than this level and it does not appear to be dropping after minutes of pumping then contact a Nanofab staff member to check the process chamber vacuum level. Note The process recipes will not allow processing to begin if the main process chamber pressure is > 5.0 E -6. Any attempts to begin processing above this pressure will result in a system error. 6

7 3.2 Selecting and Running a Recipe From the main Operation-Vacuum screen select the button labeled Run Recipe (Fig. 3) located on the upper right hand side of the touch screen. (Fig. 3) The recipe selection window (Fig. 4) will open. If the system has been idled by another user, then the first recipe selected will have to be System Startup. If the system was not in an idle state then you may skip to Step The System Start-up recipe is used to turn on the mechanical pump and turbo pump. If you are unsure of the state of the system then run the System Start-up recipe to be certain before proceeding. Highlight this recipe and proceed to the next step. (Fig. 4) 7

8 3.2.3 Once a recipe has been selected the green RUN RECIPE box will illuminate directly beneath the recipe selection window (Fig. 5). The recipe selected will be listed in the Run Recipe box. Verify the recipe listed is correct, if the recipe listed is incorrect then reselect the correct recipe from the listing. To begin processing press on the green box. At any point the Cancel button may be selected at the bottom of the Recipe Selection window to exit and stop the recipe selection process. (Fig. 5) After the System Start-up recipe has completed you may begin running your desired process recipe. Press the Run Recipe button again and select the desired process from the drop down recipe menu. Users are only allowed to run their personal recipes which have their name at the start of the recipe name and the wording Full Auto at the end of the recipe name. If additional personal recipes are needed then the user must contact Nanofab staff to have them created. ***Note The Full Auto recipes have been setup to perform all of the wafer movement and vacuum functions automatically. 8

9 3.2.5 The Load Lock (LL) will now begin venting to atmosphere. Once the LL is fully vented a PAUSED FOR notification box (Fig. 6) will appear on the screen. At this point you will open the LL door and remove the Carrier Ring and Carrier Plate from the load arm (Fig. 7). (Fig. 6) (Fig. 7) While supporting the Carrier Plate with your thumbs, flip the Carrier Plate & Carrier Ring upside down with the sample surface facing upward and sit the pair centered on top of the Loading Platform (Fig. 8). (Fig. 8) 9

10 3.2.7 Mount a sample or 1 5 diameter wafer onto the sample Carrier Plate (Fig. 9) using the clips provided. If you are depositing on a 6 diameter wafer then you will not mount it to anything proceed to the next step. (Fig. 9) To mount a 6 wafer into the Carrier Ring remove the Carrier Plate from the Carrier Ring you will not need the Carrier Plate so place it off to the side. Now position a 6 wafer centered on the Loading Platform with the side to be deposited facing upwards. The positioning of the wafer flat or notch does not matter. Lower the Carrier Ring onto the 6 wafer (Fig. 10). (Fig. 10) 10

11 3.2.9 Now use two fingers on opposite sides to hold the 6 wafer or Carrier Plate from behind while keeping your thumbs on the outer edge of the Carrier Ring (Fig. 11). In this manner the wafer will be held firmly in place inside of the Carrier Ring when it is lifted from the Loading Platform. (Fig. 11) Lift the Carrier Ring and Carrier Plate or 6 wafer off the Loading Platform and flip it upside down so that the sample is now facing downwards. Install the Carrier Ring with your sample facing downward back into the Load Arm pocket (Fig. 12). Ensure that the Carrier Ring is seated properly into the groove in the Load Arm pocket and then close the LL door. (Fig. 12) 11

12 On the main system touchscreen press the Yes button in the PAUSED FOR box (Fig. 13) to proceed. A second PAUSED FOR notification box will now open reminding you to close the LL door. Once you are sure the LL door is closed press the Yes button again to begin Auto processing. (Fig. 13) The system will now automatically pump the LL chamber down and then move your sample into the process chamber. The system will then ramp and run the target selected for the amount of time the user has set in the corresponding Process Parameters recipe (See Recipe Editing) Once the system has completed the deposition the completed sample will be moved back into the LL. The system will then issue a PAUSED FOR notification box once again. The LL will not vent for sample removal until the user presses YES to proceed Once the LL vents up, remove the sample Carrier Ring and Carrier Plate or 6 wafer and sit them centered facing upwards on the Loading Platform (See Fig. 8) Remove the deposited sample and then insert the Carrier Plate back into the Carrier ring and install the pair back into the Load Arm Pocket (See Fig. 12). The Carrier Ring and Carrier Plate should always be put back into the Load Arm Pocket when the user is finished with the system Close the LL door and select YES from the PAUSED FOR box. A second PAUSED FOR box will open asking you to verify that the LL door is closed. Select YES again and the system will pump the LL chamber down again If you have another deposition to perform then once the system has issued the Recipe Complete notification box you may return to step and begin again. You do NOT need to wait for the process chamber pressure to read < 2.0 E - 7 in order to begin processing again. If you have no further depositions to perform then proceed to the next step Once you have completed all of the necessary deposition runs then once again select the Run Recipe button (See Step 3.2.1) 12

13 Select the recipe labeled, System Idle and then press the green Run Recipe button below the drop-down menu. The System Idle recipe shuts down the mechanical pump and turbo pump. ***Note - Once the System Idle recipe has been run if you decide to run another deposition, the System Start-up recipe will have to be run again or system errors will result When you are finished depositing you must Log Out of the system by pressing the LOG OUT button in the upper right hand side of the Operation Vacuum screen (See Fig. 2). 3.3 Monitoring the Deposition Once a Full_Auto recipe has been started the system s operating parameters may be monitored by the users while the recipe is running From the Main KJL software screen there is a row of screen select buttons (Fig. 14) across the upper side of the screen. Each of these buttons opens an additional software page which allows manual control of the system and readbacks for monitoring the system hardware. The pages of primary interest to most users will be the first three pages starting from the left side of the screen. These 3 screens are Vacuum, Deposition and Gas. (Fig. 14) The first screen shown is the Vacuum screen (See Fig. 14). It shows detailed information about the vacuum system and the buttons within that screen allow manual control of the system vacuum valves, gauges and pumps. 13

14 3.3.4 The second button selects the Operation Deposition screen (Fig. 15). The Deposition screen displays RF generator power output, shutter status, manometer pressure, gas flows, etc. It is the best single page to monitor while a process is running due to the fact it gives you the most diverse information about the process. (Fig. 15) The third button selects the Gas screen (Fig. 16). The gas screen displays detailed gas system information, MFC setpoints and flows, gas valve status, and it also shows the pressure control system in more detail (Fig. 16) 14

15 4.0 Recipes Users should take care to not touch the screen or select any of the buttons displayed below the row of screen select buttons that were listed in the previous steps. Doing so could cause a system error and abort the process running on the system. 4.1 Recipe Rules and Functionality The only recipe that may be edited by a user is a recipe which has their Personal Name at the start of it and the wording Proc Parameters at the end of it A second personal recipe will be present that has the wording Full Auto at the end of the recipe name. The Full Auto recipe is NOT to be edited by the users. Editing of the Full Auto recipe could lead to system errors and in certain cases mechanical damage to the KJL sputtering system The two recipes which are named similarly, i.e. Kevin_HfO2_FULL_AUTO & Kevin_HfO2_Proc_Parameters are actually run together in the background. The proc parameters recipes are actually a sub-recipe within the matching full auto recipe The proc parameters recipes only contain the necessary set points and data needed for the user to make time, temp, flow, & pressure adjustments. System pumping and mechanical movements have been designed out of the proc parameters recipes to limit exposure to problems. 4.2 Recipe Editing The process parameters recipes may be edited by selecting the button labeled Recipe Database (Fig. 17) at the top of the right hand column of the main Operation Vacuum screen. (Fig. 17) 15

16 4.2.2 The recipe editing screen will now be opened. Because the process parameters recipes are a sub-recipe the user will have to change the viewing mode to see them in the listing. Select the button labeled Show All at the top of the recipe editing screen (Fig. 18) to change modes. Notice the mode button has changed and is now titled Show Main. (Fig. 18) All recipes and sub-recipes should now be visible when the drop-down menu (Fig. 19) is selected. Select your personal process parameters recipe that you wish to edit from the drop-down menu. Verify that the recipe listed in the box below the drop-down menu is the recipe you desire to edit. If it is not then reselect the recipe from the drop-down menu. (Fig. 19) 16

17 4.2.4 Once you have verified that the correct Process Parameters recipe has been selected you may change the desired parameter in the column titled Equipment/Test Value (Fig. 20) of the recipe window. When the recipe changes have been made you must press the UPDATE VB button at the top of the edit window for the changes to be saved. (Fig. 20) The altered recipe is now ready to be run. To switch back to the main KJL system software select the tab with what looks like the letter K inside of a yellow circle (Fig. 21) at the bottom of the screen. (Fig. 21) Once you have returned to the main KJL operation screen proceed back to Section 3.2 to begin running a recipe. 17

18 5.0 Index 5.1 Process Parameters base recipe ***Note*** The Source Shutter # s in lines 12 & 14 should match the gun # listed in the recipe name, i.e. Gun 1 = Source Shutter 1 18