Chapter 1.13

How To Write a Lab Manual Chapter

 

This document provides general guidelines for writing/updating lab manuals.

There should be 12 sections available on the equipment lab manual. Each section may have several subsections to it. All figures, including the equipment front view, parts, and panels need to be displayed in Section 11 (Figures & Schematics). New recipe generation/modification procedures, and details of recipes should be outlined in Section 12 (Appendices). Use N/A (not applicable) under a section that does not apply to your particular lab manual, however the section still needs to be included in the chapter.

Ex.:   Simply place N/A under Statistical/Process Data (Section 7.0, listed below), if there are no process data available on a particular tool.

Proper information needs to be submitted along with your new or revised manual, to include; your name, manual revision number, and a short note about the additional information/changes introduced by your new/revised manual. The hard copy of the chapter (in binders, in the lobby) has a list of revisions numbers, dates, authors and a brief description of the changes or additions placed at the end of the chapter.  The web version has a Revision History link placed in the Section 4.0 Applicable Document.. Always start with revision 00 with new manual chapter (new write ups).

Make sure to use proper numbering system in the manuals. This means all section/subsections in the lab manual should have appropriate numbers in front of them (section X, subsection X.Y and subsection to that will be defined as X.Y.Z, and so on).

Ex.:   Tystar17 operating procedure (example), listed in Section 9.0, below.

The equipment manual title should be exactly the same in three places; equipment index list, at the beginning of the manual (just below the chapter number, listed above), and in the title Section 1.0 of the lab manual, next.

1.0         Title

This section provides equipment title/name, which should be identical to what is shown at the beginning of the chapter, right below the chapter number. If it applies, specify MOS or Non-MOS clean nature of the equipment (old lab tools excluded). The equipment computer login name should be listed under the title

Ex.:   Tystar17– Non-MOS Low Stress Nitride LPCVD Furnace (tystar17)

2.0         Purpose

This section emphasizes the tool itself, and explains about the tool type, its function/capability (PURPOSE), as well as available processes (list). A short paragraph, nothing more than 4-5 lines in this section. A reminder note on the tool or processes involved may also be included here.

Ex.:   Tystar17 is a Non-MOS LPCVD furnace specially designed for depositing of Low Stress Nitride Film, and by special staff permission for deposition of High Temperature Oxide (HTO) at temperatures below 850°C, Stoichiometric nitride (stress > 1000MPa), and Oxynitride films.

Note: Non-MOS wafers are not allowed in a MOS-clean nitride tube, Tystar9.

3.0         Scope

This section focuses on the SCOPE of the lab manual itself, briefly outlines what is covered in this particular manual chapter, including recipe downloading, tool operation.

Ex.:   This document provides operational procedures for Tystar17, recipe downloading from FCS10 furnace computer, and user-level troubleshooting.

4.0         Applicable Documents

A Revision Historyl linksto a table (mpiled by M. Leullier), which lists the revision numbers, dates, authors, and a brief description of the changes or additions to the chapter.

This section should also list related/applicable documents, and vendor’s manual, if available.

Ex.:

4.1     Chapter 5.0 of the lab manual (Tystar/Tylan Furnaces Overview)

4.2         TYTAN Furnace System Manual, includes FCS10, TCU, MFS460 (Copy in Office)

4.3         The “hazardous gas booklet” at the station, which explains the safety concerns for the specific gases used in Tystar17 (includes MSDS).

5.0         Definitions & Process Terminology

Include terminology, definition of words specific to this manual.

Ex.:

5.1         MOS Furnace: This kind of furnaces is used to fabricate of MOS devices (IC), whose performance can be greatly impacted by trace contaminants. Wafers processed in MOS clean furnaces should be MOS compatible (IC device). Absolutely no metal film in any MOS Furnace, except the MOS sintering furnace, which allows only Al film.

5.2         Non-MOS Furnace: This kind of furnaces is used for Non-MOS clean process (Non IC) such as MEMS or similar application (Tystar 17 is a Non-MOS furnace).

5.3         LPCVD: Low Pressure Chemical Vapor Deposition.

6.0         Safety

This section includes safety issues specific to the tool and its operator.

Ex.:

6.1         Tystar17 utilizes high electric power (high amperage) heating elements. Do not touch high power electrical part inside panels of the furnace.

6.2         Special care must be taken when the process aborts. In some special circumstances, the tube may go into SPECIAL HOLD. In either case, inform process staff immediately. The process staff will decide whether the process can be continued, and/or take proper actions to remedy the situation. Do not try to open the tube, since there may be toxic hazardous gases in it.

6.3         All new recipes have to be approved by the process staff, before they can be used on any Tylan or Tystar furnaces.

6.4        Burn Hazard. Furnace cantilevers, boats, and wafers come out of the furnace are very hot. Wear face shield when loading/unloading wafers. Proceed with caution.

7.0         Statistical/Process Data

Refer to available data that can aid this process to include Process Monitoring section of the Microlab homepage.

Ex.:

7.1     Microlab web page.

7.2         Problem and comment section under equipment section of the wand.

7.3        Enable message for Tystar17.

8.0         Available Process, Gases, Process Notes

List processes, gases on the system, and any useful process notes specific to the tool. Available processes may also be listed in a table with specific parameters included.

Ex.:

Available Processes

8.1         Low Stress Nitride (LSN) Deposition

8.2         Stoichiometric Nitride Deposition

8.3         HTO and Oxynitride processes are being developed.

8.4         Please contact process staff for any customized processes you may need.

Available Gases

8.5         Dichlorosilane/DCS (SiH2Cl2): Used as a source of silicon in all Tystar 17 processes. Decomposition of DCS supplies silicon for LSN, HTO, Nitride and Oxynitride films.

8.6         Ammonia (NH3): Used as a source of nitrogen in the nitride process. NH3 is also used post deposition step to neutralize HCl, which is a byproduct of DCS decomposition.

8.7         Nitrous Oxide (N2O): Used as a source of oxygen for Oxynitride film deposition.

8.8         Nitrogen (N2): Used for process pressure control, tube purging, and venting the tube back to atmospheric pressure.

Process Notes

8.9         The maximum temperature for Tystar17 is 850°C. Any attempt to go above this temperature will result in damaging the O-rings used for the vacuum sealing.

8.10    The standby temperature for Tystar17 is 650°C. Avoid opening the tube for more than 30 minutes, which may cause the tube temperature to drop significantly. In such case, the stress accumulated in the films, deposited on the tube’s inner wall over the time, may crack the tube.

9.0         Operating Procedure

List step by step operation in the order steps are carried out, and in a clear/concise form. A short description may precede the steps. Please make sure all sections have a number attached to them, which will make them easier to identify, when the manual revision is in order.

Ex.:

9.1         Processing a Run (Loading recipe and wafers in Tystar17)

9.1.1          Venting the Tube

Tystar17, as well as all other LPCVD furnaces, runs STANDBY recipe when in idle. The tube is under low pressure and needs to be properly vented before you can open the door to load/unload wafers. If the tube is not vented, the tube door is under atmosphere pressure force, which could be over a few hundred pounds. Do not run any process recipes or try to open the tube door manually, which will severely damage the furnace.

9.1.1.1          Enable TYSTAR17 on the WAND.

9.1.1.2          Make sure the STANDBYA.017 is running, and the process is at WAIT step. If the VNTLK is ON, do not run any process, since there is a problem with the vacuum pump system. Report on WAND.

9.1.1.3          Press “EVENT”, and the process should advance to BKF1 (Back Fill #1). It takes 12 minutes for the venting process to finish. Afterwards, the process ends and the furnace status changes to IDLE mode.

9.1.1.4          Check the SHUNK pressure on the lower display panel. If the pressure is below 4 psi, report on the WAND. In this case, the SHUNT flow may not be sufficient to prevent the particulates back-stream from the pumping system to the process tube. Currently, we are monitoring the system to determine the cut off pressure. Once the cut off pressure is determined, this step will be included in the recipe for automatic operation.

9.1.2          Load and Run a Process Recipe

9.1.2.1          Make sure the process tube is properly vented.

9.1.2.2          Etc…

Note:    Do not leave the door open for more than 30 minutes, since it will create a large temperature gradient in the tube and causes the thick film deposited on the tube wall crack and create particulate problems. This may also crack the process tube.

In case that a wafer is broken when loading, and you need to obtain another clean one, press HOLD then BOATIN.

9.1.2.3     Etc…

9.1         General Information and Menu Key Pad Explanation

The Tystar17 is a five-zone LPCVD furnace. It operates as a stand-alone unit that comprises of three modules: wafers load/unload module, furnace/process tube module, and gas control module. It has it’s own computer, FCS10, whose display panel and keypad are located on the left side of the wafer load/unload module. The furnace operation is controlled by using the special function buttons and a series of menu commands. The furnace temperature is controlled by the TCU computer board that runs a proprietary PID algorithm. The temperatures of all 5-furnace zones, i.e. Load, Load/Center, Center, Source/Center, and Source, can be independently set. The process gases are controlled by the MFS460 controller that has five hardware interlocks to insure the safety of the operation.

9.2.1          Front Panel Special Function Buttons and Keypad Description (see Section 11.1 for the schematics of the front panel):

ABORT                   ***USE  ONLY IN EMERGENGY***, e.g. fire, toxic gas leak. DO NOT use this key to abort a recipe in progress. If you must stop a recipe, please contact a super-user or process staff. They know the proper procedure for stopping process/evacuating toxic gases from the furnace. This action requires password, as well.

MENU                     Displays the main menu (See Section 12.0 for the description of all menu commands)

Etc…

9.2.2          Commonly Used MENU Commands (press MENU button, then enter the two letter commands)

DS        Displays the current status of the furnace. An example is shown in Section 11.2.

DH        Displays the process history from the last time the RUN button was pressed to present time.

DR        Displays the contents of the selected recipe.

GS       Changes the Display to graphic mode. It shows large characters with only selected process information. Use CMD button to select process parameters to be displayed.

RL        Loads process recipes. You will be prompted to use the Arrow Keys to select a recipe. Afterward, press ENTER button twice. The computer will prompt you to enter process parameters, if/when needed.

9.2.3          Process Gas Flow Interlocks

When any of the following five interlocks turns ON, no process gas, except nitrogen, will flow. If the ANTLK is on, the nitrogen cannot flow either.

DNTLK    Door Interlock. When ON, it indicates that the tube door is not closed properly.

ANTLK    Above Atmosphere Pressure Interlock. When ON, the tube pressure is above 760 Torr.

BNTLK    Below Process Pressure Interlock. When ON, the process pressure is above 2 Torr.

VNTLK    Vacuum Interlock. When ON, it indicates that the vacuum system is not working.

GNTLK    Gate Interlock. When ON, the gate valve between the vacuum pump and process tube is closed.

9.3         Available Recipes

There are four process recipes available on this furnace. A staff or super users should be consulted whenever a new recipe is needed. The John Goldman computer is used for setting up new recipes. No one should ever upload a recipe from the menu driven terminal to the John Goldman computer.

9.3.1          STANDBYA.017: Standby recipe. It purges with a small amount of nitrogen through the process tube at low pressure to keep it clean.

9.3.2          LSNSTDA.017: Standard Low Stress Nitride LPCVD. The deposition condition is fixed (100 DCS / 25 NH3 / 140 mTorr / 835°C). Enter only the deposition time, based on your target film thickness, when loading recipe.

9.3.3          LSNVARA.017: Variable Low Stress Nitride LPCVD. The process gas flows and pressure are specified by the user, while the temperature is fixed at 835°C. The recommended DCS flow is 100 sccm, and you can reduce the NH3 flow to obtain lower stress in the film.

9.3.4          STDNITA.017: Stoichiometric Nitride LPCVD. The process condition is fixed (25DCS/75NH3/300mTorr/800°C). The stress can reach above 1000 MPa.

Note: Due to the current setup, the actual pressure during deposition is around 200 mTorr.

10.0      Troubleshooting Guidelines

Include useful information that an operator can carry out to resolve issues, and before filing a problem report.

Ex.:

10.1      The tube is at atmospheric pressure hold (step HLD2). In this case, there is no film deposition on your wafers.

10.1.1      Cause         The tube door has not closed properly (DNTLK is ON).

            Solution      Make sure there is nothing on the track blocking the movement of the boats.

                              Press EVENT three times (The boats will move out, then in, and the process end).

                              Run the process again. Press EVENT twice and the door will start moving in.

                              If the DNTLK is still ON when recipe reaches BPP1, the system needs to be checked. Report the problem on WAND.

10.1.2      Cause         The tube failed leak check. (No interlock is ON)

            Solution      Press EVENT three times (The boats will move out, then in, and the process end).

                              Run the process again. When the tube door is completely open, check the door flange and tube’s open-end area for any debris that may result in leakage. Wipe the flange with Technicloth. To prevent burn injury, pay extra attention on the hot spots of the boat loader when doing so.

10.2      The tube is at abort hold (step APRG). In this case, the process was aborted when the process gases were flowing. There is some film deposition on your wafers.

10.2.1      Cause         One of the process gas flows was out of tolerance due to delivery system malfunction or gas cylinder getting empty.

            Solution      Press MENU, then enter DH. Press ENTER when prompted for input. The whole process history for this run will be displayed. Find the root cause for the abort and report on the WAND.

Etc…

11.0      Figures & Schematics

Include figures and schematics of control panels, tool itself and any displays that you wish to include for reference in the manual text.

Ex.:

11.1      Furnace Status Displayed on the FCS10 Front Panel (Idle state of the standby recipe)

FNC: DS – Display Process Status         STANDBYA.017

MODE: RUN                              END: 00.00.00   STEP: IDLE                              ST_TTG: 00.00.00

SIGNAL

SETPT

ACTUAL

SIGNAL

SETPT

ACTUAL

SIGNAL

SETPT

SIGNAL

ACTUAL

N2

 

DCS

 

NH3

 

N2O

 

Etc…

5000 G

 

0   G

 

0   G

 

0   G

 

 

5000

 

0

 

0

 

0

 

TEMPL

TEMPLC

TEMPC

TEMPPSC

TEMPS

 

RMPRATE

 

 

300.0 G

300.0 G

300.0 G

300.0 G

300.0 G

 

300.0 G

298.0

299.9

301.9

302.1

296.0

 

0

 

 

 

BOATOUT

 

BOATIN

 

SHUNT

 

SHUNKMKS

OFF

 

OFF

 

OFF

 

OFF

LNTLK

ANTLK

BNTLK

VNTLK

GNTLK

BPAUTO

OUTLMT

OFF

OFF

ON

OFF

OFF

OFF

OFF

 

12.0      Appendices

Include procedures, command list, detail recipes, and any information that you think will be helpful for this manual in here. This will help maintain flow and continuity in Section 8.0 and 9.0 above, otherwise burden with extra material that belongs to appendices.

Ex.:

FCS10 Furnace Computer Manu Commands

D - Display Sub-Menu

DE        Equipment status

            Etc…

The following sub-menu commands should not be used, but are stated for completeness and to satisfy your curiosity.

H - Host computer Sub-Menu

HP        Host Parameters

C - Configuration Sub-Menu

CC        Contact Closures

CM       MFS460 gases

CT        TCU temperature

CS        Station options

CA        Alarm selection

X - Diagnostics Sub-Menu

XM       Memory utility

TI (change time, date) and PW (change password) have no submenu. Don't use these commands.