>>> 'topgun' problem from hebert -- Thu Jan  4 15:26:53 1990 <<<

Problem: New RF gun needs cooling water and biasing.

         The SiO2 target arrived today and I installed it.

         The target needs 3 gallons/minute cooling water.
         
         Lesker will contact me on 1/5 with the bias voltage that
         is needed.

>>> 'topgun' problem from hebert -- Mon Jan  8 08:06:42 1990 <<<

Problem: Film uniformity with existing rotation table is not
         as good as I'd like it to be. At 3.0 spin speed, Mo
         film thickness varies by about 8% across a 100 mm wafer
         when depositing Mo at 400 A/min.

         I'd like to get the other substrate table installed
         (i.e. the one that not only rotates by moves in and
          out along radius at the same time).

>>> 'topgun' problem from hebert -- Wed Jan 10 10:40:30 1990 <<<

I installed the water lines and power cable to the new Torus 10E s-gun.
The plasma ignites and is uniform over the SiO2 target. The problem
is that there is RF leakage from either the chamber or the power
supply that causes all of the electronics in the equipment rack
to be effected when the RF power exceeds 100 W. Reflected power
is only a few watts. RF interference effects the Ar gas valve,
causing it to open and close and the plasma to turn on and off.
The interference also effects the ionization gauge controller,
the shutter control, and the MKS baratron.

>>> 'topgun' problem from hebert -- Tue Jan 16 08:06:39 1990 <<<

I connected the RF matching network to the Torus 10E. Upon
powering up, small sparks arced between the matchning network and
the Varian DC s-gun used for depositing molybdenum. There was
also a burning smell.

>>> 'topgun' problem from rnorman -- Tue Jan 16 14:44:10 1990 <<<

Problem: Small sparks between matching network and s-gun.

Cause: Possibly grounding not well enought.

Solution: Attached grounding cap of new gun securely by installing
          all screws.  Also, ran a breaded ground cable to all
          three guns, as a test.  Turned on RF power and tuned in
          well, then increased power and retuned. The RF power was
          up to 250 watts with no sparks.  There was reflected power
          of 30 watts, Dave said this was  high.  We may pull a RF
          supply and matching network for another system to see if
          it works better.  The topgun is up.

>>> 'topgun' problem from hebert -- Wed Jan 17 15:41:47 1990 <<<

Problem: The Henry 1000D RF power supply fired up to 30 W forward
power then shut down. Since then, it will not power up even
though the "STANDBY" light comes on.

PA GRID and PA VOLT are both zero, and PA FIL is 5.0 VAC.

It looks like the transformers are set for 220-240 VAC, as the
step down is using taps 1 and 3.

The manual states that taps 1 and 2 should be used for 200-215 VAC.
Is this the voltage being used? If so, could this cause the
power supply not to fire up?

>>> 'topgun' problem from rnorman -- Thu Jan 18 12:36:28 1990 <<<

Problem: Report of possible transformer connected wrong.

Solution: Checked out the connection and was correct.  The RF supply
          will not operate, there is no PA voltage.  We may have
          lost the RF tube.  This report is on the RF supply brought
          from the 5th floor, an unused supply.  When I get some time
          I will try to repair it.

>>> 'topgun' problem from hebert -- Thu Jan 18 16:04:14 1990 <<<

Problems: 1) RF leakage effecting electronics in the rack, and
             the electronics of adjacent dep systems in the old lab.
          2) Unable to go above 100 W RF without Ar gas valve closing.
          3) Poor matching using the Ptherm match network/supply.

Solution: I attached new copper ground straps to the lid, side wall,
          and bottom lid. The copper is 1 - 2 inches wide and solder
          tinned at the connections. Previously there was only a
          copper ground strap to the side wall and the substrate
          rotation motor housing. The old copper strip was corroded
          due to a small water leak at the quick disconnect water
          line behind the TOPGUN (just above the copper water pipe).

          I removed paint from the DC s-gun mounting clamps to improve
          the grounding of the s-gun sidewalls to the top lid.

          I was able to deposit SiO2 at 100 A/min using: 500 W forward;
          70 W reflected; 5 mTorr Ar; substrate to target distance
          of about 4 inches. The new ground straps have greatly reduced
          RF leakage from the chamber.

Problem 1 and 2 above are resolved. Problem 3 still exists: I cannot get
a perfecxt match to a 50 ohm dummy load. The best I can get is 150 W
forward and about 70 W reflected. There appears to be a problem with the
matching network or perhaps we have some bad RF cables. The water leak
in the 1/4 in dia water hose behind the TOPGUN still needs to be fixed.

>>> 'topgun' problem from rnorman -- Fri Jan 19 06:39:10 1990 <<<

At this time there is a small H2O leak behind the topgun in a quick-disconnect.
Also, the RF matching network has fairly high reflected power; we either have 
bad cables or the matching network does not work well. 

>>> 'topgun' problem from hebert -- Fri Jan 19 12:04:49 1990 <<<

Problems: 1) High reflected power.
          2) Ionization gauge won't turn on.

Solution to #1: I made new RF cables and the reflected power
          thru the TORUS 10 E is now less than 1% of the
          forward power. At 460 W forward, I had 4 W reflected.

Problem #2 needs to be addressed. I need to put the test IG on
to see if I have a bad ionization gauge on the TOPGUN.

>>> 'topgun' problem from rnorman -- Mon Jan 22 06:12:21 1990 <<<

Problem: IG tube not turning on.

Cause: Most likely the pressure in the chamber was not low enough.

Solution: When we came in on Saturday for the power shutdown I turned on
        the IG with no problem.  The topgun is up.

>>> 'topgun' problem from hebert -- Thu Feb  8 07:08:39 1990 <<<

Problem: Potential measured between the cathode and anode of the
         Torus 10E (SiO2 target) sputter dep gun.

With the power supply OFF and the RF cable disconnected from the gun,
I measure a potential of 350 mV between the cathode and anode when the
city cooling water is in the target but not flowing. When the water is
flowing, the potential drops to about 125 mV (DC). I am able to measure
a DC current between the cathode and anode or about 2 microamperes. When
the water is blown out of the cooling channel of the s-gun, there is
no measurable DC voltage.

Checking for voltage between the incoming copper water pipe and earth ground
shows that there is no potential difference between the copper pipe and
ground. This eliminates the source of the DC voltage from a voltage
being induced somewhere on the copper water pipe. 

I have had inconsistent RF matching results. Last week I found that by
connecting a copper strap from the target anode to earth ground that I
had no RF leakage but reflected power as high as 30% of the forward
power. At that time, if I removed this one grounding strap from the 
target anode, I had a lot of RF leakage but reflected power was low:
about 2% (max) of the forward power. Going with the "no RF leakage"
high reflected power configuration, the SiO2 dep rate was only about
40 A/min. The dep rate was 100 A/min with the "high RF leakage" configuration.
The problem with using the "high RF leakage" configuration is that it
seriously effects the electronics in all equipment racks within about
20 feet of the TOPGUN.

On 2/6/90, I disconnected the target anode grounding strap and for the first
time I had very low RF leakage and low reflected power. I had never observed
this before without this particular ground strap in place. I was able
to keep a RF plasma going at 450 W RF with about 15 W reflected power
for about 15 minutes (with the cooling water circulating thru the target).
After about 15 minutes, the reflected power increased to 90 W and I wasn't
able to improve the RF match. Also, the RF leakage increased at this time.

On 2/7/90 I used the HI POT to check the Torus 10E target. With the cooling
water (city water) in the target, there was a short between the anode
and cathode at 150 VDC (90 microamps leakage current at 150 VDC). With
the cooling water blown out of the target, I was able to apply a bias
of 4000 VDC between the anode and cathode before breakdown. I also HI POTTED
all of the RF cables and the matching network: all of these had breakdown
voltages above 1800 VDC.

It is possible that the city cooling water resistivity varys during the day
and that it is marginal for use as cooling water in the TORUS 10E. The
design of the Torus 10E cooling channel and the path length between the
anode and cathode may be sufficiently short that the resistivity of the
city water is causing shorting between the electrodes. This would effect
RF leakage: the target cooling water tubes at various times are carrying
RF thru the water line. This has been observed to happen on the Gartek
when the coolant resistivity decreases. Also, a similar observation was
made on the SEMI about 1 1/2 years ago: plasma flickered for about
a week, and then plasma wouldn't ignite. Initially it was thought that
the SEMI RF power supply was down, but HI POT test of the powered substrate
table to ground showed a short. The problem with the SEMI at that time
was resolved by changing the M&W coolant, as the glycol resistivity had
decreased.

Solution: The Torus 10E HI POT test indicates that the cooling water is
conductive enough to cause a short in that s-gun. This may explain some
or even all of the inconsistent RF match/leakage problems that I've
observed on this gun in the past weeks. The installation of DI water cooling
(closed loop) or a resin bed should eliminate the cooling water as a
contributor to these problems.

NOTE: I have NOT been able to improve the RF match by blowing the water
out of the target. The reflected power is just as high without cooling
water in the target. The only explanation that I have for this is that
blowing the water out of the target allows a DC potential to be applied
between the anode and cathode, but with RF there is still leakage between
the electrodes due to the cooling channel not being completely dry
and RF conductance being more at the surface of the channels than DC
conductance.

>>> 'topgun' problem from hebert -- Thu Feb  8 10:06:36 1990 <<<

Problem: high reflected power/poor matching.

The matching network output connector is missing 2 of 4 prongs
that make contact to the RF cable center lead. It is an intermittent
open circuit with the RF cable attached. This connect needs tp be
replaced. The Part Number is 74868  UG-58 U. We do not have any stock
on this item. I have pulled the connector and will try to get one
from the Plasma Shop. Otherwise I will have to hard wire the output
cable to the matching network.

>>> 'topgun' problem from hebert -- Thu Feb  8 11:36:51 1990 <<<

Problem: high reflected power.

Solution: I replaced the connector on the output side of the
matching network. I now have reflected power less than 5% of
the forward power up to 450 W. At 500 W, the reflected power
is almost 10% of the forward power. The gas pressure is 5 mTorr.
There is a moderate amount of RF leakage effecting the electronics.
The forward and reflected power readings are from an RF power
meter added to the power cable at the phase mag box. I think that
the RF leakage and interference with the electronics will be
reduced when the resistivity of the cooling water increases
by adding a resin bed.

Any word on when the resin bed will get here?

>>> 'topgun' problem from hebert -- Thu Feb  8 11:41:17 1990 <<<

Problem: RF power meters on the RF generator do not agree with
the in-line RF power meter. The in-line meter agrees pretty well
with the RF meters on the Gartek. I think that the TOPGUN RF
power meters are tweeked and need to be replaced.

>>> 'topgun' problem from hebert -- Tue Feb 27 11:53:39 1990 <<<

I enabled the system at 7:30 AM this morning. Somehow it got
disabled at about 11:40 AM, possibly when the Taurus override
was shut off. I enabled again, and the Taurus box wouldn't
turn on, and the wand states that I had just turned on the TOPGUN.

The danger with this is that the Taurus interlock turns OFF my
target cooling water when the system is disabled. I was sputtering
SiO2 and the cooling water was off because the system had been
disabled.

A new Taurus interlock needs to be installed. I'd prefer to have it
attached to the N2 vent or to the top lid drive motor.

That way I can sputter without losing my cooling water when the
Taurus override is turned off.

I can't operate the system at this time because there is no cooling
water flow/the Taurus box won't turn on.

>>> 'topgun' problem from rnorman -- Tue Feb 27 12:56:31 1990 <<<

Problem: Could not enable topgun.

Solution: Could not duplicate, the taurus box LED turns on.
          I did find the main H2O shutt-off turned off; this
          valve is behind the topgun.  The topgun is up.

 NOTE: I will talk to bob about moving the taurus interlock
       to the vent.
.

>>> 'topgun' problem from rnorman -- Tue Mar  6 06:44:47 1990 <<<

The topgun will be down shortly to move the taurus interlock
from the water to the N2 vent;  give me til 7:30 am.

>>> 'topgun' problem from rnorman -- Tue Mar  6 07:30:20 1990 <<<

Problem: Taurus water interlock could cause damage to targets.

Solution: The interlock was moved to the vent line.  I also
          repaired a water leak on the ultek supply line that was
          leaking on the topgun main grounding connection, a fitting
          was loose.  The topgun is up.

>>> 'topgun' problem from hebert -- Tue Mar  6 09:35:55 1990 <<<

Problem: Substrate table rotary feedthrough wobbles.

James Parrish says that he may have a 1/2 in feedthrough that can
replace the 3/8 in dia feedthrough currently in the chamber.

>>> 'topgun' problem from hebert -- Tue Mar  6 09:37:12 1990 <<<

Problem: N2 vent is slow. It takes about 2 to 3 times longer t
vent the chamber since the Taurus interlock was switched from the
cooling water to N2 vent.

>>> 'topgun' problem from rnorman -- Tue Mar  6 10:52:17 1990 <<<

ProbProblem: N2 vent takes 2-3 times longer.

Cause: The taurus interlock was moved to the Vent or N2 line; the 
       solenoid limits the N2 flow.

Solution: Hebert could increase the N2 pressure to increase N2 flow.
          It may be better as is, there will be less partical contamination
          on wafer.  The topgun is operational.

>>> 'topgun' problem from hebert -- Tue Mar  6 12:01:41 1990 <<<

Problem: The N2 vent solenoid (120V) is hot to the touch. It has a
         1/16 in dia orifice, and the N2 vent line is 0.25 in dia
         tubing. 

Assuming the tube i.d. is 0.15 inches, the cross sectional area of the
0.25 o.d. tube is 0.017 square inches.

The cross sectional area of a 1/16 in orifice is 0.003 inches.

What this means is that at a given N2 line pressure, the vent up
time is about 6 times longer with the orifice solenoid orifice in-line.
Even is the line pressure is doubled, the vent up time is still about
3 times longer than it was.

Is there a solenoid available with a larger orifice? As mentioned,
the solenoid is hot, and I'm not sure that it is supposed to be at
such a high temp.

If a solenoid with a larger orifice is not available, I'd like the other
Taurus interlock option installed: interlock with the hoist UP so that
the chamber can't be entered if the system is not enabled.

In regards to my earlier report on long vent up cycle: I didn't actually
time the vent cycle. It does take too long though. Particulates have NOT
been a problem when venting. 

>>> 'topgun' problem from rnorman -- Tue Mar  6 13:19:12 1990 <<<

Problem: N2 vent too slow.

Cause: Taurus interlock solenoid orifice 1/16".

Solution: The solenoid was replaced with one that has a larger
          orifice size, 1/4".   The topgun is ready for use.

>>> 'topgun' problem from hebert -- Wed Mar 14 14:05:30 1990 <<<

Problem: Substrate rotation feedthrough has excessive eccentricity.

Solution: The feedthrough has been pulled. It will be machined
          with extension rods in place so that it rotates true.

>>> 'topgun' problem from hebert -- Thu Apr 12 11:54:48 1990 <<<

I have been He leak testing the chamber to locate a leak that
prevents the chamber from going below the mid 10E-5 Torr range.
So far the only leak that I've detected is at the Ar Nupro valve.

 I pumped out the Ar gas line to the bottle. The Ar Nupro
valve is leaking. When the Ar Nupro is closed, the leak rate
is high and positiive. When the Ar Nupro is opened, the leak
rate (as indicated by the He leak detector) decreases significantly.

I need either a replacement Nupro valve (VCR fittings) or a Nupro
rebuild kit (and som,eone to rebuild the valve if possible).

>>> 'topgun' problem from hebert -- Thu Apr 12 

The light on the topgun's resin beds has gone out indicating
they need changing. A new 1.2 M/B has been ordered. A 1.2
M/B is rated for about 2000 gallons of EBMUD/UC water
before replacement is needed.


>>> 'topgun' problem from hebert -- Fri Apr 13 15:56:02 1990 <<<

I cleaned the Ar Nupro valve seat. It didn't look dirty. I replaced
the crush seal. The leak is still present after doing this.

>>> 'topgun' problem from rnorman -- Mon Apr 16 08:08:39 1990 <<<

I am leak checking the leaking Nupro valve at this time.

>>> 'topgun' problem from rnorman -- Mon Apr 16 08:13:40 1990 <<<

After leak checking the nupro I found a leak across the valve
seat, by means of the leak detector.  I will replace the seat and
install the nupro , then leak check again.

>>> 'topgun' fix from hebert -- Mon Apr 16 08:51:54 1990 <<<

Problem: Substrate rotation stops above 100 W RF with max torque/speed
set on motor controller.

Solution: Electrically isolating the motor housing from the chamber
          allowed the substrate table to rotate up to 150 W RF.
          Adding a ground strap between the motor controller and earth
          ground permitted rotation up to 200 W RF. Switching the ground
          strap from between the controller and earth ground to between
          the controller and the drive motor housing permits the substrate
          table to rotate up to 500 W RF (i.e. the upper limit of the RF
          power supply).

>>> 'topgun' problem from hebert -- Mon Apr 16 08:56:16 1990 <<<

RNorman is fixing the leak in the Ar Nupro valve. I blanked off the
tube where the Nupro mounts, and there is still a leak. The chamber
pressure rises to over 200 mTorr within a few minutes of closing
the high vac valve. Additional He leak testing is required to locate

the leak.

>>> 'topgun' problem from rnorman -- Mon Apr 16 09:49:00 1990 <<<

The nupro valve seat and gasket was replaced.  It was then leak
checked on the hld and was leak tight.  The nupro was installed
on the topgun and hebert is now leak checking the system for a leak.
He will report his findings.

>>> 'topgun' fix from hebert -- Wed Apr 18 08:32:50 1990 <<<

The leak was found to be at a braze in the water cooling loop
of the xtal monitor. I removed the monitor and blanked off the
hole. The base pressure in the TOPGUN is in the mid 10E-7 Torr 
range this morning. TOPGUN IS UP.
