Cambridge NanoTech: Savannah S100. Table of Contents

Transcription

1 Table of Contents 1.0 Purpose/Scope Reference Documents Equipment/Supplies/Material Safety Logbook Login and Launch Software Session Setup Load/Edit/Save Recipe Load Sample: Run Recipe Abort Recipe: Unload Sample: Purge Manifold: Terminate Software and Log Off Recipe Command Defintion Tables:: Figures Miscellaneous REV B Page 1 of 15

2 Purpose/Scope 1.1 This document covers the procedure that should be followed for normal operation of the (Atomic Layer Deposition ALD). This tool is design to be used with whole 4 inch wafers. Smaller pieces can be secured to a bare silicon wafer with Kapton tape to prevent their loss to the pump port. This tool must only be used for deposition less than 50nm. Contact NanoFab Staff if thicker depositions are desired. (Remember ALD) At present there are three precursors connected to the tool to deposit Al2O3, HfO2 and TiO2. Submit proposal for other precursors you may want to use. Deviation from this procedure can result loss of access up to a submittal of a strike. IMPORTANT: Substrates coated with gold are allowed in the S100. If your product is sensitive to gold contamination then it is highly recommended that you coat the empty chamber prior to processing live material. In addition, any sample that has gold on the backside must use a silicon carrier wafer to prevent the gold contacting any chamber surface. Reference Documents 2.1 Stanford Nanofabrication Facility: This information is very useful for the understanding of ASU/ NanoFab s Savannah S100 tool. Website: Equipment/Supplies/Material 3.1 Wafer Tweezers 3.2 Kapton Tape (for small substrate that would be prone to loss in the vacuum port) Safety CHAMBER IS LIKELY TO BE HOT! ASSUME THIS TO BE ALWAYS TRUE! ALWAYS PLACE THE PROTECTIVE BARRIER OVER THE CHAMBER LID TO PREVENT ACIDENTAL CONTACT BURN HAZARD. IMPORTANT: At this elevate temperature, take care that your sample will not offgas material that could contaminate the chamber and other deposition efforts. CAUTION: Do not attempt to open chamber lid until target chamber temperature is achieved (~180degrees C). Read and understand this entire document. Consult NanoFab Staff if you have questions. Please report any problems directly to NanoFab and document all issues in the log book. Additionally, if necessary, place the STATUS of the tool to DOWN and generate an Online SR. Check the fluid level in the Vacuum Pump (inside the tool cabinet). If fluid LEVEL IS LOW, contact NanoFab to replenish. REV B Page 2 of 15

3 Log book 5.1 Prior to usage, fill the Log Book with the Date, Full Name, Deposition Film, Recipe Name, Number of Cycles, Measured Thickness, Start Time, Stop Time and Substrate: Composition/Comments. Include any odd occurrences. The maximum allowed target thickness is 50nm. Written approval must be received prior to running films thicker than 50nm. A process variance can be requested by sending an to the NanoFab tool owner. Login and Launch Software 6.1 This computer is a stand-alone PC. All user will login with these credentials: USER: CSSER_ALD PWD: NANOFAB_ALD 6.2 Dbl-Clk: Cambridge Icon (Shortcut on the desktop), Savannah, V (See: 17.1) 6.3 If software launches successful, GOTO 7.0, otherwise GOTO Note: Occasionally there will be an USB Error, that is encountered. (See: 17.2) If you encounter this error: Lt-Clk: OK. This will terminate the software Lt-Clk: File/Exit to close the software (returning to the desktop) Turn OFF the circuit breaker (CB) at the front of the tool cabinet Wait five seconds and turn ON the CB Wait 15 seconds, for the PC to recognize the EBOX (USB device) Dbl-Clk: Cambridge Icon (Shortcut on the desktop), Savannah, V (See: 17.1) Session Setup 7.1 Lt-Clk: PUMP button, the button will change to read VENT. 7.2 Enter the base pressure in the logbook (0 sccmn2). 7.3 Lt-Clk: HEATER (ON), the button will change to read (OFF). From room temperature, it will take about 30minutes to get the precursor manifold to the set point temperature of 150 o C. DO NOT ATTEMPT TO OPEN CHAMBER until temperature is achieved. Damage to the Chamber Lid O-ring seal will occur 7.4 OPEN Precursor Valve. Manifold Order: Front to the Rear. Water (no valve) Valve/Position: 0, TDAHf 1Turn Valve/Position: 1, TMA 1Turn Valve/Position: 2, TDMAT 1/4Turn Valve/Position: 3 REV B Page 3 of 15

4 Load/Edit/Save Recipe 8.1 Rt-Clk: Anywhere in the program area (See:17.3) 8.2 Lt-Clk: LOAD RECIPE. The popup menu will allow you to import an existing recipe Note: Use recipe as a starting template. PATH: Recipe/Sample Recipes (See: 17.4) 8.3 Calculate the number of cycles needed to hit the target film thickness. (For Al2O3 1A/Cycle) 8.4 Edit the GOTO command line with this value. 8.5 Rt-Clk: SAVE RECIPE. Create a new folder with your NAME. (Place it within the same directory as Maintenance.) 8.6 See: 15.0 for definition of the Recipe Commands Load Sample ONLY WHEN THE CHAMBER TARGET TEMPERATURE IS ACHIEVED. (180 o C) CAUTION: If loss of sample is a possibility, secure your sample with Kapton tape onto a bare 4 inch silicon carrier wafer. 9.1 Remove the chamber barrier and hang it on the hook on the right side of the cabinet. 9.2 Lt-Clk: VENT Button, the button changes to read PUMP. The chamber pressure is reflected on the pressure window. 9.3 Use the protected lid handle and open the chamber lid. 9.4 USE TWEEZER and place substrate to be coated into the wafer recess at the bottom of the chamber. Note: Side to be coated should be faced up 9.5 Use the protected lid handle and close the chamber lid 9.6 Replace the chamber barrier over the chamber. 9.7 Lt-Clk: PUMP Button, Button changes to read VENT. 9.8 The chamber pressure is reflected on the pressure window. 9.9 Type 5 sccm for N2 CARRIER and ENTER. (See:17.5) The chamber pressure is reflected on the pressure window Enter the stabilized chamber pressure in the logbook (5 sccm N2) 9.11 Allow your wafer to warm up to chamber temperatures (5-10min) 9.12 Do not proceed until ALL the temperature set points have been achieved. REV B Page 4 of 15

5 Run Recipe IMPORTANT: It is the researcher's responsibility to safeguard their sample from possible cross-contamination while using this tool. Coating an empty chamber is recommended prior to processing your sample Lt-Clk: RUN (START). Button changes to read ABORT. (See: 17.6) 10.2 Lt-Clk: YES, to acknowledge this action in the prompt that appears. Recipe will automatically run to completion, unless ABORTED by the user Recipe progress can be tracked by following the Blue Highlight (Instruction) in the programming area or at the top of the screen Green Text. (See: 17.7) 10.4 There are three timers that can be selected. 1) Done At, 2) Time Left, 3) Total Run Time 10.5 Alternating pulse signals can be tracked for the selected precursor and the water. Note: At the START, if the precursor pulse is missing, it is likely that the valve is not open. If the water pulse is missing, ABORT THE SESSION. And, notify staff. Water source cylinder is likely empty. It is filled using DI water. It is recommended that users monitor the progress of their deposition. It is understood that deposition can be lengthy, however assuring that the pulse magnitude is consistent and present insures your deposition is predictable. Precursors will eventually run out and water source requires periodic refills RECIPE COMPLETION: The Progress line (at the top of the screen) will display, RUN HAS COMPLETED, when the recipe terminates normally. Hint: TIMER is a useful feature in determining when the program will complete. Abort Recipe (follow below - If needed, otherwise goto 12.0) 11.1 Lt-Clk: RUN (ABORT). Button changes to read START. (See: 17.8) 11.2 Lt-Clk: YES, to acknowledge this action in the prompt that appears (See: 17.9) Unload Sample 12.1 Remove the chamber barrier and hang it on the hook on the right side of the cabinet Lt-Clk: VENT Button, the button changes to read PUMP Use the protected lid handle and open the chamber lid USE TWEEZER and remove substrate from the wafer recess in the chamber 12.5 At this point, a second wafer can be inserted Use the protected lid handle and close the chamber lid 12.7 Replace the chamber barrier over the chamber EDIT/SAVE new recipe with different parameters or initiate another session 12.9 Lt-Clk: RUN (START). Starts next deposition session REV B Page 5 of 15

6 Purge Manifold (At the end of your session or when changing Film Deposition) Purge Manifold is intended to maintain system cleanliness. NOTIFY NanoFab when multiple films on a single substrate are to be deposited CLOSE Precursor Valve. ALL the precursors valves should be closed Rt-Clk: In the programing area (anywhere) 13.3 Lt-Clk: LOAD RECIPE. The popup menu will allow you to import an existing recipe 13.4 Note: Use as a starting template. PATH: Recipe/Maintenance Recipe 13.5 Dbl-Clk: Purge x, the number (x) corresponds to the precursor position (See: 17.10) 13.6 Lt-Clk: PUMP Button, Button changes to read VENT Lt-Clk: RUN (START). Button changes to read ABORT. Allow this recipe to terminate normally 2minutes. Typically a single pulse will be generated. Precursor valve may be open, if multiple pulses are generated and if the size of the pulses do not decrease. (See: 17.11) 13.8 REPEAT from 13.2, if multiple precursor valves were opened Lt-Clk: HEATER (OFF), the button will change to read (ON). Terminate Software and Log Off 14.1 Lt-Clk: PROGRAM (STOP) Button 14.2 Lt-Clk: YES to acknowledge this action in the prompt that appears. The screen image will change slightly Lt-Clk: File/Exit (See:17.12) 14.4 Log Off normally from the Windows Desktop Measure the film thickness on a metrology tool (Woollam Ellipsometer) 14.6 Enter the thickness measurement in the log book. IMPORTANT: This is the primary datum used for the timely ordering precursor cylinders. REV B Page 6 of 15

7 Recipe Command Definition (Source: Stanford NanoFab) The parameters you can control in a recipe are listed below with comments about each: Parameter Heater Flow Pulse goto stabilize wait stopvalve line ac out Notes Each heater has an unique item number and a value given in degrees Celsius. Do not overheat precursors (all precursors should be below 85C and some should not be heated at all). The reaction chamber should only be operated in the range of C. The manifold and exhaust lines should be maintained at 150C to avoid any condensation. This controls the flow of nitrogen carrier gas flowing through the system. It is defined in sccm. Typical recipes use a flow of 20sccm, and when in standby the system is lowered to 5sccm flow to reduce N2 usage. The source is the house nitrogen line. This command is for pulsing a precursor line. It requires an ALD valve number and the amount of time you want the valve open in seconds. The fastest these valves can fire is roughly.015 seconds, so note that even if you define a shorter time that is likely the valve open time you will get. (NOTE: when writing a recipe the time in seconds needs a digit to the left of the decimal place; thus you should use "0.015" instead of ".015" for the minimum duration pulse.) Used to define loops in the recipes. This command takes as an input the step to which the recipe should return. The value for this command defines how many times the loop will run. This command is used to hold a recipe until a heater has reached the desired value. It takes as input a heater ID number and will wait until that heater demonstrates the set temperature with a degree C over a few seconds. This command takes as input a value in seconds that you would like the system to wait before proceeding to the next command. (NOTE: when writing a recipe the time in seconds needs a digit to the left of the decimal place, as noted earlier in Pulse) This command will close or open the output valve for the reaction chamber depending on a Boolean input. This command is currently not used in any of the standard recipes, but development for recipe use of this feature may be conducted, time permitting. Users should not use this command. It changes the heater voltage on precursor heater wraps. REV B Page 7 of 15

8 Growth Rate Plots Dose = 15 ms Al2O3 Growth Rate Thickness ( Å) y = 0.88 x Number of Cycles REV B Page 8 of 15

9 Figures REV B Page 9 of 15

10 Program area Pressure: Auto-scales REV B Page 10 of 15

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12 Progress 17.7 Timers Pulse Signal 17.8 REV B Page 12 of 15

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14 Miscellaneous: Cylinder Capacity (water): 50ml. Refill with 25ml. REV B Page 14 of 15

15 Effective Date Originator DESCRIPTION OF REVISION Issue 2/19/13 Art Handugan Original Release O 5/30/13 Art Handugan Gas configuration change A 5/16/18 Art Handugan Accommodate gold in tool Sec.15 thru 17 unchanged B REV B Page 15 of 15