ProbeStation < Sandbox

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---+ CERN HGTD Probe Station
---++ Introduction

This twiki contains instructions for using the HGTD probe station to make IV or CV measurements.

Location: 161/1-006
---++ Equipment

---+++ Experimental setup

   * A Keithley 2410 source meter (on loan from the CERN ITk Group, who have our thanks!)
   * A Keithley 6487 picoammeter (on loan from the CERN Epool)
   * A micro PC (Windows 10/Linux)
   * A probe station (on loan from the CERN ITk Group)
   * A vacuum pump (to ensure that the sensor remains in place on the chuck)
   * XIMEA camera to take pictures of the sensor through the microscope
   * You can install the camera software here (already installed on lab PC): https://www.ximea.com/support/wiki/allprod/XIMEA_CamTool
   * To open the software click the xiCamTool shortcut on the desktop (applies in both Windows and Linux)
   * Make sure the light is on (and the source meter is off!) in the probe station or no image will be visible!

   * Measurements are controlled using a labview project (Windows only) developed for the probe station setup used by RD-50.
     %TWISTY{
     mode="div"
     showlink="Details"
     hidelink="Hide details"
     showimgright="%ICONURLPATH{toggleopen-small}%"
     hideimgright="%ICONURLPATH{toggleclose-small}%"
     }%
      * The git repo containing the labview programs used by RD-50 is: [[https://gitlab.cern.ch/SSD/cviv-daq.git]]
      * Necessary drivers can be found here: [[https://gitlab.cern.ch/SSD/lv-instrument-drivers.git]]
      * Many thanks to Isidre Mateu, Michael Moll, Matteo Centis Vignali and Marcos Fernandez Garcia for kindly allowing us to use their software.
%ENDTWISTY%

<img alt="ProbeStationLabels.001.jpeg" height="768" src="%ATTACHURLPATH%/ProbeStationLabels.001.jpeg" width="1024" />
---+++ Pin controls
   * Pins are used to supply the HV, ground the guard ring and connect the sensor pad, as shown in the left image below.
   * The pins are connected as follows (as illustrated in the lower right schematic):
      * the pin closest to the cabinet door is to ground the guard ring,
      * the middle pin provides the HV to the chuck,
      * the further pin is to measure the current through the sensor pad.

<img alt="20190605_131434.jpg" height="345" src="%ATTACHURLPATH%/20190605_131434.jpg" width="460" /><img alt="PinConnections.001.jpeg" height="360" src="%ATTACHURLPATH%/PinConnections.001.jpeg" width="520" />

   * To position the pins on the pad or guard ring is tricky. Look through the microscope and use the small knobs on the needle mounts.
      * The function of each of these knobs is shown in the schematic below:
 <img alt="PinDiagram.001.jpeg" height="600" src="%ATTACHURLPATH%/PinDiagram.001.jpeg" width="900" />

---++ Instructions for measurements

The [[LAr.HGTDSensors#IV.CV][HGTDSensors twiki]] contains instructions/recommendations for making sensor tests.
Currently we're keeping the CERN team measurements in this [[https://docs.google.com/spreadsheets/d/1oxOZ4U7se8u02IMCVPRE9tNCmGTZEtAhGKFhdhbc6Cg/edit?usp=sharing][spreadsheet]].

To set up the PC for IV or CV measurements:
   * Switch on computer, booting up Windows
   * Load up labview project:
      * Documents &rarr; Labview project &rarr; cviv-daq &rarr; CVIV
      * Select CV-IV-control.vi from the list of options displayed in LLB Manager
      * When the CV-IV-control.vi project opens, click on the %ICON{arrowright}%, %M% button on the menu bar
         * This takes you from edit mode to running mode
   * Fill out the relevant fields in the labview GUI according to the measurements you wish to make (see following sections).

---+++ IV (floating guard ring)

---++++ Labview settings
| *Parameter* | *Setting* | *Comment* |
| Device name | Sensor name | Usually this should be the name written on the sensor packaging. This will be the name of the folder in which the results will be stored. |
| Drop down menu to right of "Device name" | pFZ | Default assuming non-irradiated sensors. |
| Tester | <your name> | |
| Type of measurement | IV | Select from drop-down menu. |
| Start | 0 V  | |
| Stop | -100 V  | This is the max voltage for the scan (will differ between sensors). Note that the value must be negative. |
| Number of steps | Calculate (2V) | e.g. Start: 0, Stop: -100, Number of steps: 50 |
| Step mode | linear | |
| Compl. Stop | ON | This ensures that the measurement cycle will cease, and the voltage ramp down, should the sensor reach the compliance you set. |
| GPIB | 21 | Port for Keithley 2410 |
| Integration time | 3 [20 ms] |
| Averaging (count) | 3 | Number of measurements taken at a single voltage point for averaging. |
| Compliance. | 1e-6 A | Sensor dependent (have seen nA currents for HPK Type 1) |

---+++ IV (grounded guard ring)

---++++ Connecting the sensor
   * Ensuring the voltage source is off, open the probe station cabinet and switch on the light.
      * The light switch is located in the back left-hand corner of the cabinet.
   * Turn on the vacuum pump.
      * Turbulence from the pump the instant it is switched on will cause the sensor to move violently if you try to turn on the pump after placing the sensor!
   * Using plastic tweezers, gently place the sensor onto the chuck, positioning it over the small hole in the centre.
      * The sensor should completely cover the hole so that the vacuum is effective.
   * Position the needles on the sensor, as shown below.

<img align="middle" alt="PinsOnSensor.png" height="456" src="%ATTACHURLPATH%/PinsOnSensor.png" width="614" />

   * Switch off the light and close the cabinet doors.


---++++ Labview settings
| *Parameter* | *Setting* | *Comment* |
| Device name | Sensor name | Usually this should be the name written on the sensor packaging. This will be the name of the folder in which the results will be stored. |
| Drop down menu to right of "Device name"  | pFZ | Default assuming non-irradiated sensors. |
| Tester | <your name> | |
| Type of measurement |  IV with two I-meter | Select from drop-down menu. |
| Start | 0 V  | |
| Stop | -100 V  | This is the max voltage for the scan (will differ between sensors). Note that the value must be negative. |
| Number of steps | Calculate (2V) | e.g. Start: 0, Stop: -100, Number of steps: 50 |
| Step mode | linear | |
| Compl. Stop | ON | This ensures that the measurement cycle will cease, and the voltage ramp down, should the sensor reach the compliance you set. |
| V source and I meter | Keithley 2410 | Select from drop-down menu. |
| I meter | Keithley 6487 | Select from drop-down menu. |
| GPIB address (Keithley 24xx) | 21 | Port for Keithley 2410 |
| GPIB address (Keithley 6487) | ?? | Port for Keithley 6487 |
| Integration time | 3 [20 ms] |
| Averaging (count) | 3 | Number of measurements taken at a single voltage point for averaging. |
| Compliance. | 1e-6 A | Sensor dependent (have seen nA currents for HPK Type 1) |

---++ Analysis of IV/CV data:
   * Data is stored in Documents &rarr; Labview project &rarr; cviv-daq &rarr; CVIV folder
   * Code to make IV plots from the raw data can be found here: [[https://gitlab.cern.ch/CERNHGTD/ivlabview]]

---++ Useful links

   * [[LAr.HGTDSensors][HGTDSensors twiki]]

   * [[https://gitlab.cern.ch/CERNHGTD][CERN HGTD team gitlab area]]

-- Main.EmmaKuwertz - 2019-05-21

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
jpg	20190605_131434.jpg	r1	manage	3861.1 K	2019-07-10 - 19:40	EmmaKuwertz	Pins on chuck
jpeg	PinConnections.001.jpeg	r2 r1	manage	124.5 K	2019-07-10 - 20:09	EmmaKuwertz	Diagram showing which pin connectors go where
jpeg	PinDiagram.001.jpeg	r1	manage	124.5 K	2019-07-10 - 20:00	EmmaKuwertz	Pin controls
png	PinsOnSensor.png	r1	manage	1153.3 K	2019-07-10 - 20:49	EmmaKuwertz
jpg	ProbeStation.jpg	r2 r1	manage	4807.1 K	2019-07-10 - 20:29	EmmaKuwertz
jpeg	ProbeStationLabels.001.jpeg	r1	manage	440.4 K	2019-07-10 - 20:37	EmmaKuwertz

This topic: Sandbox > WebPreferences > ProbeStation
Topic revision: r2 - 2019-07-10 - EmmaKuwertz

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