Coating processes – Direct application of electrical – magnetic – wave – or... – Pretreatment of substrate or post-treatment of coated substrate
Reexamination Certificate
2001-05-04
2003-03-25
Meeks, Timothy (Department: 1762)
Coating processes
Direct application of electrical, magnetic, wave, or...
Pretreatment of substrate or post-treatment of coated substrate
C427S579000, C427S237000, C427S255270, C427S255370, C134S001100, C134S004000, C134S008000, C134S022100, C204S192370
Reexamination Certificate
active
06537622
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of Invention
The invention related to a method of prevention of particle pollution in a pre-clean chamber, in particular, to a method for preventing particle pollution in a pre-clean chamber of a physical vapor deposition (PVD) device.
2. Related Art
During a procedure of integrated circuit (IC) manufacture, PVD devices are employed to deposite thin metal film. PVD devices, as shown in
FIG. 1
, include mainly a buffer chamber
1
, a pre-clean chamber
2
, a transfer chamber
3
, a process chamber
4
and a robot arm
5
.
Wherein, the pre-clean chamber
2
addresses the cleaning procedure of a Wafer
6
. As illustrated in
FIG. 2
, the pre-clean chamber
2
includes a radio frequency (RF) generator
21
, a bell-jar
22
, a shield
23
and a pre-clean chamber body
24
. During cleaning a wafer
6
, the wafer
6
is moved by the robot arm
5
into the pre-clean chamber
2
, and then argon gas is injected into the pre-clean chamber
2
to be ionized into plasma using the RF wave from the RF generator
21
. (as illustrated in FIG.
3
). Thereafter, the plasma produced above is sputtered onto the wafer
6
to clean the surface of wafer
6
.
As described above, due to plasma sputtering in the procedure of cleaning wafers
6
some parts of the wafer
6
would be split off onto the bell-jar
22
and the shield
23
. Meanwhile, when the metal deposition in PVD is that of a gate procedure, the majority of the parts split off the wafer
6
are silicon, in other words, after some pre-clearings, a large amount of silicon-rich oxide will accumulate on the bell-jar
22
and the shield
23
.
In general, the bell-jar
22
are made of quartz onto which silicon-rich oxide can not adhere well, and so peeling-off occurs to pollute the pre-clean chamber
2
and the wafer
6
therein when there is a big amount of silicon-rich oxide accumulating on bell-jar
22
.
After all, the pollution will cut the efficiency of the following process. To solve this problem, manufacturers in this industry have to clean the bell-jar
22
from time to time to prevent the pollution of particles peeling off from the bell-jar
22
.
However, cleaning the bell-jar
22
means stopping of manufacturing, and lower efficiency. And so, how to prolong the life of the bell-jar
22
of the pre-clean chamber
2
and to reduce time for cleaning the bell-jar
22
is the key for efficiency in this business.
SUMMARY OF THE INVENTION
With problem as above, the objective of this invention is to lessen the particle pollution of pre-clean chambers, to prolong the life of bell-jars, to cut short the frequency of clearing of bell-jars
22
and to upgrade the efficiency of the production line.
The method for preventing particle pollution in a pre-clean chamber according to the invention is featured by injecting oxygen gas into the pre-clean chamber, and ionizing the oxygen gas therein by RF wave into plasma, which would interacts with silicon-rich oxide split off a wafer to form a silicon oxide layer to cover the bell-jar. And so, peeling-off of silicon-rich oxide is prevented by a layer of silicon oxide and the life of the bell-jars is prolonged.
To achieve the object mentioned above, a method for rapid preventing particles in a pre-clean chamber according to the invention includes following steps:
An oxygen gas supplying step for injecting oxygen gas into a pre-clean chamber, and
A plasma generating step for electrify the oxygen gas therein into plasma by RF wave, and then the plasma produced above interacts with silicon-rich oxide to form a silicon oxide layer in the pre-clean chamber.
Wherein, due to better adherence of the silica and the bell-jar, the interaction of the oxygen gas and the silicon-rich oxide formed on the bell-jar of the pre-clean chamber produces the silicon oxide layer so as to avoid the peeling of silicon-rich oxide off the bell-jar, and to prolong the life of the bell-jar.
REFERENCES:
patent: 5961793 (1999-10-01), Ngan
patent: 6143144 (2000-11-01), Golovato et al.
patent: 6413321 (2002-07-01), Kim et al.
patent: 11-269644 (1999-10-01), None
Huang Chao-yuan
Kuo Chia-ming
Meeks Timothy
Silicon Integrated Systems Corp.
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