Chapter 5.7

TYLAN7

MOS Clean Dry Oxidation and Annealing

Atmospheric Furnace (4” Only)

(Tylan7)

1.0        Title

TYLAN7 MOS Clean Dry Oxidation and Annealing Atmospheric Furnace (4” Only)

2.0        Purpose

TYLAN7 is an atmospheric furnaces that is designed for Gate oxidation, Dry oxidation and Nitrogen Annealing. The furnace accommodates wafers up to 4” in diameter.

3.0        Scope

This chapter covers the general furnace description of TYLAN7, TYCOM Terminal and operation procedures which include process recipe loading, wafer loading/unloading, user level problem diagnosis, and wafer cleaning requirements.

4.0        Applicable Documents

Revision History

4.1        TYTAN Diffusion Furnace System Instruction Manual (copy in Office).

4.2        TYCOM 9900 Microprocessor Control System Instruction Manual (copy in Office)

4.3        Oxide Growth Chart, Semiconductor Technology Handbook (in the binder stored under TYCOM terminal)

4.4        Material Safety Data Sheets for TCA (1,1,1-Trichloroethene), Oxygen, Nitrogen, and Forming Gas H2/N2 (copy in Lobby).

5.0        Definitions & Process Terminology

5.1        MOS Furnace: This kind of furnaces is used to fabricate MOS devices (IC), whose performance can be greatly impacted by trace contaminants. Wafers processed in a MOS furnace should absolutely 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: The wafers processed in this kind of furnaces may contain materials that are not compatible with the MOS processes. If CMOS devices are processed in a Non-MOS furnace, the electric performance of the devices may be changed. Wafers with metal films can be processed in Non-MOS furnaces only with Microlab managerial permission.

5.3        Dry/Wet Oxidation: A high temperature process that oxidizes the underlying silicon to form silicon oxide. Dry oxidation uses oxygen for better process control. Wet oxidation uses both DI water and oxygen for fast reaction rate.

5.4        Gate Oxidation: A special dry oxidation process that produces high quality oxide with precise thickness control.

5.5        Annealing: A high temperature process that uses nitrogen to keep wafers in an inert atmosphere. Major applications include dopant diffusion and activation, LTO/PSG densification, film stress release, and etc.

5.6        TCA Cleaning: A high temperature process that uses TCA and oxygen to clean the furnace quartz parts and interior, by removing possible metallic contaminants in these areas.

6.0        Safety

Follow general safety guidelines in the lab as well as the specific safety rules as per follow:

6.1        Electric Shock Hazard: TYSTAR furnaces utilize high electric power (high amperages) to generate heat.  Do not open the side panels or touch the high power electrical parts in the furnace cabinet.

6.2        Chemical Hazard: TCA (1,1,1-Trichloroethene) is used for in-situ cleaning of quartz wares. It poses moderate health and high fire hazard. Please refer to the MSDS for first aid information.

6.3        Burn Hazard. Cantilevers, boats, and wafers coming out of the furnace are very hot.  Wear face shield when loading/unloading wafers. Proceed with caution. Avoid touching of any furnace quartz ware to prevent burning of your hands and contamination of the furnace. No flammable chemical, especially organic solvents, in the load station when the tube is open.

6.4        All new recipes must be checked by the process staff, before they can be used on any TYLAN furnaces. Customized recipes should be stored on the user’s diskette, not the standard diskettes.

7.0        Statistical/Process Data

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

7.2        Enable message for individual TYSTAR furnace.

8.0        Available Process, Gases, Process Notes

Available Processes

8.1           Dry Oxidation (maximum temperature 1050ºC).

8.2           Nitrogen annealing (maximum temperature 1050ºC).

Available Gases

8.3        Nitrogen (N2): Used to purge out room air and keep the process tube in an inert atmosphere.

8.4        Oxygen (O2): Used for dry/wet oxidation.

8.5        TCA (C2H3Cl3): Used for in-situ process tube cleaning.

8.6        Nitrogen Carrier (N2cARR): Used to carry TCA vapor to the process tube.

Process Notes

8.7        Wafer cleaning requirements before loading into TYLAN furnaces (See also Chapter 5.0)

8.7.1   Photo-resist on the wafer surface must be stripped first in PRS3000 bath of Sink5, Technics-C, or Matrix. Then cleaned in Sink8 (4”) piranha bath. New wafers can skip this step.

8.7.2   All wafers then cleaned in Sink6 piranha bath. Wafers just unloaded from an MOS furnace can be loaded into another furnace without further cleaning.

8.8        Additional wafer requirement for the MOS furnaces: Only new wafers and wafers processed only in MOS clean furnaces can be loaded into a MOS furnace after cleaning. Wafers that have been processed in a Non-MOS furnace or have gone through any Non-MOS processes can not be loaded into any MOS furnace. ABSOLUTELY NO EXCEPTION.

8.9        No wafer processed with any metal films, even the film is stripped or covered, is not allowed in TYLAN7

9.0        Overall Furnace Operation

9.1        General TYLAN Furnace Information

The TYLAN Furnace consists of three basic modules: Load Station Module, Furnace Module, and Source Cabinet Module. Microlab members have access to the Load Station Module in the clean room area. The other two modules are in the Tylan service chase. Only Microlab staff with proper training has access to these two modules due to potential hazards.

The Load Station Module houses a laminar flow unit with HEPA filter for clean air distribution. A Boat Loader Unit opens/closes the furnace door and pulls-out/pushes-in the cantilevers with wafer boats sitting on top. The operation can be automatically controlled by a process recipe, or manually using the ROP (see Section 9.3).

The Furnace Module consists of a quartz process tube, thermal couples, and heating elements. It is divided into three zones: Load, Center, and Source. The temperature is controlled through a PID electronic board (DTC). All the control parameters can be set in the process recipe. The volume of the quartz tube is approximately 25 liters. The process gas flows into the tube from the Source end and vented through a hole on the Load end.

The Source Cabinet Module contains several Mass Flow Controllers (MFC), which regulate the process gas flows, and the TCA bubbler.

9.2        TYCOM Terminal

The TYCOM Terminal controls/monitors all the TYLAN/TYSTAR Furnace operations. It consists of a CPU with two floppy disk drives, a CRT monitor and a keyboard. Disk drive #2, on the right side, is used for viewing and loading of recipes. The auxiliary drive is used for copying diskettes. The floppy disk used has a special format. All the standard TYLAN7 recipes are store on the diskette labeled “STANDARD DISK”. Please ask staff if you need one to store your customized recipes.

9.2.1   TYCOM Commands – TYCOM CPU only recognizes CAPITAL letters only. You can use the numerical key pad on the right hand side of the keyboard to enter numbers. However, do not use the [Enter] key on the numerical key pad. It will cause error when loading a recipe.

Commands

Function

Example

DI DI

Displays the recipe directory of the diskette in Drive #2

 

DI RE “recipe name”

Displays the content of a recipe on the diskette in Drive #2

DI RE DRYOXA

LO “recipe name” “#”

Load a recipe to a TYSTAR furnace

LO DRYOXA

DI ST “#”

Displays current status of a TYSTAR furnace (see Section 9.2.2)

DI ST 7

DI DE “#”

Displays the system configuration of a TYSTAR furnace

DI DE 7

DI AL “#”

Displays previous process alarms of a TYSTAR furnace

DI AL 7

9.2.2   Display Furnace Status - When you use DI ST commands, the CRT monitor displays the status of the TYSTAR furnace. This information is very important, especially for equipment problem diagnosis. The following example is used to explain the information users should know. The furnace status to be displayed is TYLAN7 with recipe HIN2ANNL loaded but not running (Idle state).

02/023/07

16:30:32

 

 

 

 

 

 

 

 

*=DISABLED

 

 

 

 

 

 

 

TUBE

STATUS

PROCID

 

ET

 

STEP

TIME-TO-GO

STEP ET

007

READY

HIN2ANNL

 

00:00:00

 

0000

00:00:00

00:00:00

 

 

 

 

 

 

 

 

 

 

OUTPUTS

RELAYOUT

RELAYIN

INPUTS

 

 

N2 =

0.9

N2 =

ON

CCIN1 =

OFF

TEMPL =

H

750.2

2118

ANA02 =

0

CCOUT2 = 

OFF

O2PRS =

OFF

TEMPC =

G

750.5

0632

O2 =

.0

O2 =

OFF

CCIN3 =

OFF

TEMPS =

G

749.5

0895

ANA04 =

.0

N2CARR =

OFF

CCIN4 =

OFF

CALIBL =

 

752.1

 

ANA05 =

.0

VENT =

OFF

CCIN5 =

OFF

CALIBC =

 

750.9

 

ANA06 =

.0

CCOUT6 =

OFF

BPIN =

ON

CALIBS =

 

747.3

 

ANA07 =

.0

CCOUT7 =

OFF

BPOUT =

OFF

 

 

 

 

ANA08 =

.0

CCOUT8 =

OFF

CCIN8 =

OFF

 

 

 

 

TEMPL =

750.0

CCOUT9 =

OFF

 

 

N2 =

G

0.9

 

TEMPC =

750.0

CCOUT10 =

OFF

 

 

ANA02 =

G

.0

 

TEMPS =

750.0

CCOUT11 =

OFF

 

 

O2 =

G

.0

 

 

 

CCOUT12 =

OFF

 

 

N2CARR =

G

.0

 

 

 

CCOUT13 =

OFF