CENTROTHERM E1200 HT 260-3, Operating Instructions Manual

Page: 222 / 233

E1200 HT 260-3
9BPreventive Maintenance
23.04.07
10-42
00401010_41087
10.14 Process Dependent Measures
10.14.1 Cleaning resp. Replacing SiC / Quartz Process Tubes
Deposition thickness is a result of the addition of the depositions on the wafers during
the process runs.
The following statement for quartz process tubes is valid as standard value for
polysilicon, LTO, TEOS-oxide, oxidation and diffusion processes:
—
If less than 300 - 400 nm deposition thickness are deposited upon the wafer during
a process run, the larger value of the stated range is valid.
—
If more than 300 - 400 nm deposition thickness are deposited upon the wafer
during a process run, the smaller value of the stated range is valid.
The following statement for quartz process tubes is valid as standard value for silicon
nitride processes:
—
If less than 150 - 200 nm deposition thickness are deposited upon the wafer during
a process run, the larger value of the stated range is valid.
—
If more than 150 - 200 nm deposition thickness are deposited upon the wafer
during a process run, the smaller value of the stated range is valid.
Process tube
material
Process Etching according to
deposition thickness Replacing according to
deposition thickness
polysilicon 25 - 50 µm
silicon nitride 10 -20 µm 25 - 50 µm
LTO 25 - 50 µm
TEOS oxide 25 - 50 µm 50 -100 µm
oxidation *)
quartz
diffusion *)
oxidation *) SiC
diffusion *)
*) Carry out a chlorine-guiding cleaning once per week using HCl or DCE if quartz resp.
SiC process tubes are used for oxidation or diffusion processes. The cleaning does not
have to be carried out if other chlorine-guiding processes are carried out periodically.
For information on the cleaning recipe, see chapter 12.6 Information on Process
Technology, page 12-2.
For information on the installation of process tubes, see chapter 9.4.2 Installing the
Process Tube, page 9-41.