AIXTRON CRIUS II - Showerhead

AIXTRON - Dokumentation CONFIDENTIAL 63
3
crius_II_en_00, Edition 06/2010
System Manual Description
CRIUS II Reactor
3.5.1 Showerhead
Fig. 3-8,  63 shows the showerhead. It has 100 tubes/inch
2
with a tube diam-
eter of 0.6 mm.
The showerhead to susceptor spacing is normally 11 mm on a GaN system,
and 16 mm on a GaAs/InP system.
The spacing may be adjusted either by fixed spacer rings, or by the optional
servo mechanism (range: 5 mm to 25 mm).
Fig. 3-8 Reactor lid with showerhead
A Showerhead
B Gas feedthroughs
The showerhead normally has two plenums, see Fig. 3-9,  63. In rare cases
a third plenum can be added to prevent prereactions occurring.
For a normal two plenum showerhead, the configuration is as follows:
• Upper plenum:
Feeds the group III elements using metal organics
• Lower plenum:
Feeds the group V elements using hydride gases such as NH
3
or AsH
3
Fig. 3-9 Showerhead (cross section)
C
D
E
A
B
A Showerhead Cap
B Showerhead Body
C Upper plenum
D Lower plenum
E Water cooling