A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at http://www.rbdinstruments.com
If you have an older Balzers Pfeiffer Duo 1.5 mechanical pump that needs to be rebuilt and want to do it yourself, here is a link to a detailed procedure:
The calibration procedure provided with the 9103 USB Picoammeter is written for use with a Keithley 220 current source and is set up for semi-automatic operation. But what if you want to use another brand or type of current source? The following procedure shows you exactly how to calibrate and verify calibration using any current source.
Preparing for Calibration
In order to calibrate your 9103 Picoammeter, you will need a calibrated current source, and software that can send / receive ASCII commands to the Picoammeter. If you are using the Actuel application supplied with your Picoammeter, there is a built in console window that allows you to communicate directly with the Picoammeter using ASCII commands – simply click the Console button to open the window and type the commands in the field provided.
Note that when using Actuel’s console window, the ampersand character “&” that precedes all commands is automatically entered for you – you do not have to type it.
Note also that the offset and gain calibration apply to all 7 ranges. Range 1 corresponds to the highest resolution range in nA, range 7 corresponds to the lowest resolution range in mA. The Gain Reference Table (at the end of this article) shows the ideal calibration values and limits for each range (both positive and negative polarity).
Perform OFFSET Calibration and VerificationCalibrate Offset (all ranges)
Wait for completion (about 30 seconds), until message received “OPEN CIRCUIT Offset Calibration Completed!”
Verify Offset for (all ranges)
Ensure that the current input is disconnected
Send the &I0500 command to start receiving data samples
Send command &R# (where # is a number 1 through 7) to manually select the range to be verified (see the Gain Reference Table below)
Verify measured values received are zero and have at least 1 zero after the decimal point
Repeat until all ranges are checked
Perform GAIN calibration
Refer to the Gain Reference Table below for interpretation of the current values and limits.
Send the &+CC command to unlock the calibration function. The green LED will begin flashing
Connect the current source to the 9103 input
Turn on current source. Ensure current source is at proper operating temperature before proceeding
Send command &C2, and wait for prompt from 9103: “Apply test current…”
Using your calibrated current source, input the specified test current (see table below) and send command &C2 again, the 9103 will respond with “Measuring and calibrating gain…”
Repeat the current application for each of the 7 ranges and polarities, following the prompts provided by the 9103
Wait for response from the 9103: “Gain Calibration completed!”
Perform GAIN verification
Send command &R0 (select auto-ranging)
Send command &I0500 (sample interval 500 mSec)
For each test current (shown in the Gain Reference Table below), set the source to the specified current and select the appropriate current range on the 9103 in turn (&R1, &R2, &R3, &R4, &R5, &R6, &R7), monitoring the data stream for at least 10 seconds after each range, and ensuring that the readings are stable in each range (if a message starting with &S* appears indicating an unstable value, wait a little longer)
Verify that the measured value reported by the 9103 is within 1% of the set current for each range
Send command &I000 to stop sampling
Disconnect current source and turn off the 9103 – calibration is complete
Gain Reference Table
(14 test currents are shown, positive/negative polarities for each of the 7 ranges)
RBD Instruments’ proprietary technique for rebuilding the PHI 04-303 ion gun and 06-350 ion source filament assembly results in more stable sputter rates and longer filament lifetimes than other ionizers. The pictures below are actual 04-303 ion source filament assemblies which show the visible light emitting from the filaments. Note that the 3 post RBD ionizers have a much larger and more uniform hot spot than the 5 post PHI filament. In terms of performance, a more uniform hot spot results in a more uniform beam shape. In addition, even with the additional two unnecessary posts, the PHI filaments will still slightly warp out of position over time. That in turn changes the sputter rate of the ion gun, which can result in inaccurate depth profile data unless you re-calibrate your sputter rate frequently.
In short, the RBD ion source filament assemblies outperform the PHI filaments, last longer, and the cost 75% less than a new ionizer. So the next time your 04-303 or 06-350 ion gun needs a new ion source filament assembly, send it to RBD for a rebuild! You will save $$ and get the benefits of a longer lifetime ion source filament assembly and more stable sputter rates.
RBD carries exchange ion source filament assemblies so we can send you a rebuilt one and then you return your old one to us after you install the rebuilt ion source filament assembly.