2004/09/07 Junkichi Asai (RBRC) (Kieran Boyle (SBU)) Sensor QA at BNL 2004/09/07 Junkichi Asai (RBRC) (Kieran Boyle (SBU)) I would like to talk about the evaluation of Stripixel sensor at BNL. I and Kieran study the sensor QA.

Contents Previous Evaluation of Stripixel Sensor Preparation Result IV (leakage current –Voltage) CV (Capacitance-Voltage) (at BNL) Preparation Semi-automatic probe station IV measurement with comb type Effect of grounding other strips on IV measurement Schedule of sensor QA Development/production These are the contents. First, I will show the result of IV/CV measured previously at BNL with manual probe station. Next, I will talk about the Semi-Automatic Probe station and Measurements with Switch System Finally, I will show the schedule of sensor QA.

Setup for IV/CV measurement Dark Box Micro Scope picture Measured Needle to sensor pad Grounded Needle to guard ring Micro Scope Measured Needle Vacuum hole wafer Grounded Needle chuck These are the setup for IV/CV measurement. In the dark box, the silicon wafer putted on the chuck. In this picture, there are no wafer. The bias voltage supplied to the chuck. Because the pad size so small, the probe needle is contacted the pad of the wafer by watching through the microscope. The grounded needle contacted the Guard ring. With this manual station we measured leakage current and strip capacitance. Later I would like to talk about semi-automatic station. chuck Bias Voltage Because the pad size so small, the probe needle is contacted the pad of the wafer by watching through the microscope. There are in the Instrumentation Division.

Result : IV/CV measurements We found leakage current in the range of 100’s nA and capacitance in the 10s of pF range. These are the result of leakage current and capacitance measurement. The x axis is bias voltage, y axis are the current and capacitance. We found dark current in the range of 100’s of nA and capacitance in the 10s of pF range. 400um strip sensor

Effect of grounding other strip Micro Scope 100 Measured Needle to sensor pad Grounded Needle to guard ring Leakage current (uA) 10-1 With Grounded Needle to neighbor pad decrease current 10-2 wafer 10-1 10-1 100 101 102 103 Grounded Needle to neighbor pad chuck Bias Voltage (V) For these measurements, an adjacent channel was grounded. The leakage current decreases by around 1/3. Bias Voltage We measured the leakage current for effect of grounding other strip. For the measurement, another one needle grounded on the neighbor pad. The leakage current decreases by around 1/3.

Why Semi-Automatic Probe station With the present manual probe station, measuring one entire wafer (200 measurements) takes ~ 2 weeks. To speed up, We use the Semi-Automatic Probe Station With the present manual probe station, measuring one entire wafer (200 measurements) takes ~ 2 weeks. To speed up, we use the Semi-Automatic Probe Station.

Setup Semi-Automatic Probe station Microscope Dark Box Windows LabView controlled All device through GPIB cable. Ribbon Cable Probe card Probe positioner for Guard Ring Probe stage HV/Ammeter Keithley 6487 Windows LabView sensor chuck The semi-automatic probe station consist of these device pictured here. This probe station has a movable chuck which the silicon wafer is placed on. With the microscope, we can check the contact of the sensor pad and the needles. For the measurement, we use a probe card, it has 128 needles. For grounding the guard ring, we use a probe positioner. A ribbon cable carries the signal to our switcher system. All the devices are controlled by windows Labview software through GPIB cables. The HV/Ammeter and LCR are connected to the scanners. Now , this set up is in the Instrumentation Division. But in September, they will be moved to the RIKEN Lab room in physics building. In the room, the clean tent will be set up. Then we can start measurements. GPIB Cable Movable stage LCR Meter Agilent 4263B Switch system Keithley 7002 Probe station Early Oct., they will be moved to the RIKEN Lab room in physics building at BNL. In the room, the clean tent will be set up. Then we can start measurement.

Probe Card 64 x strip needles By RUCKER & KOLLS, INC. 80um 330um 64 u strip needles We see here the probe card. It has 64 x and 64 u strip needles. The dimensions are here. One needle is used to measure, the other 127 are grounded. We measure all 384 channels. 80um One needle is used to measure, the other127 are grounded Measurement all 384 pad of strip with overlap step by step 150um

Semi-Automatic Probe station with Imaging card COMB type sensor u pads The needles contacted with the u pads This is the pictured window of probe card needles and the u pad. It was pictured by the Imaging card. We can check without looking through the microscope. This is the picture of the needles contacted with the u pads. And this is the maximum zoom. With this, we can check the contacting. 64 u needles of probe card Maximum zoom It was pictured by the Imaging card. We can check without looking through the microscope. Check the contacting

IV/CV measurement schematic Chuck GND Ring n-1 measured This is the IV/CV measurement schematic. The keithley 7002 system controls these switches. In the IV case, the switch is set this way. In the CV case, the switch is set this way. In the CV measurement of between strip by strip, the switches are connected like this. Now. I am making the program. Keithley 7002,7011,7153 switch system Keithley 6487 HV/Ammeter Agilent 4263B LCR Meter CV Measurement (Between strip-strip) CV Measurement IV Measurement (Between strip-strip) IV Measurement

Result of IV measurement with Semi-Automatic Probe station Using COMB design for practice Here is an IV for the semiautomatic probe station using COMB design for practice.

Effect of grounding other strips GND needle: 14 GND needle: 10 GND needle: 6 GND needle: 4 GND needle: 2 GND needle: 1 GND needle: 0 Measured This is the effect of grounding other strip on IV measurement with probe card and switch system. I think it need at least 4 or 6 grounding needles for the 1 strip measurement. We should QA test it with new sensor. Needles of Probe Card 400um Electric Field

Schedule of silicon sensor Preproduction Sensor Soon SINTEF 17 wafers are supposed to arrive at RIKEN, yesterday (9/6) (500um, STD design, 2 type : sintering process deference) They will be shipped to BNL and UNM, when clean room ready(?) End of Sep. 20 sensors from Hamamatsu (4 type : thickness=(500um, 625um) , design=(STD, New)) Clean Room Early Oct. build at RIKEN Lab room in BNL QA test Now Programing Semi-Automatic station with LabView Wiring (probe card, Scanner, HV/Am, LCR…) should decide how to measurement Sep. IV/CV measurement at UNM (with probe positoner) Continue studying sensor response with probe card at BNL Oct. IV/CV measurement at BNL All wafers are expected to complete QA in Dec. 2004 or earlier Finally, I would like to talk about the schedule of silicon strip detector.