(8”x8”) MCPs Resistance Optimization by ALD Sept 20, 2011 Anil Mane, Jeffrey Elam

MCP Rs requirements 2 Items20 micron 33mm Workable resistance range for 20 micron 33mm MCP50Mohm - 4Gohm Workable resistance range for 20 micron 8”x8” MCP1Mohm-85Mohm Electrode on top/BottomDoes this matter? AnnealingNeeded SEE layerMgO preferred

8” 20µm MCP Substrates Back from ANL 9/2011 Scrap and Observations of the surfaces on the next few pages. There seem to be handling issues. We have data from Anil showing both MCPs asymptote to ~220 MΩ Neither were Annealed by Anil at ANL. On assembly we find that the air resistance of the MCPs is about 5.5 MΩ for the pair. On pump down, repeated several times, and with varying clamp pressure we get consistent results, - always resistance goes to ~70 GΩ as we go below a few Torr. This was checked with the multimeter and with I/V curve data. So unfortunately we cannot test these MCPs. Maybe we have to anneal the large MCPs to get stable resistance (Many PHOTONIS MCPs behave this way too, air low R, vacuum high R) Can the MCP resistance be reduced by additional ALD layers?? Feedback form UCB on 20 micron 8”x8” plates In first impression why ANL and UCB electrical results are not in-line? Courtesy: Prof. Ossy

Processed 4 wafers with different ALD Chem.#2 composition 4 MCPResistance in ANL by Keithley 6487 Resistance in UCB Multimenter 20 micron 8x8 pair ~20 Mohm5.5Mohm  Rs values in air measured at ANL and UCB are in-line Magnified plot

20 micron 33mm MCP resistance comparison :air vs. vacuum (NiCr electrode deposited at Photonics ) Air Torr Air Vent slow open Vent quickly open Torr 100V applied constantly (ohm) 04/27/2010 data posted on LAPD blog No ALD coating only bare MCP data  Bare MCPs are very moisture sensitive 1G  vs. 700G 

6 MCP # Resistance (  ) In airin vacuum E E+11  MCP77 resistance in air is lower compare MCP61 20 micron 33mm MCP resistance comparison :air vs. vacuum (Cr electrode deposited at CNM) 04/27/2010 data posted on LAPD blog No ALD coating only bare MCP data 35M  vs. 195G 

MCP resistance comparison in air vs. vacuum (Photonics NiCr electrode) No ALD coating only MCP data Table 1: 33mm MCP (20 micron) MCPResistance in AirResistance in vacuum 8x8 ( calculated form MCP77) 0.73 M  4.15 G  8x8 ( calculated form MCP61) 22 M  15 G  8x8 MCP IDResistance in Air Resistance in vacuum M  1.5G  Table 2: 8”x8”(20micron) 1x(8”x8”) = 46.8 x (33mm MCP) Table 3: 8”x8”(20 micron) Actual measurements MCP ( ) (UCB NiCr electrode) Air Vac. MCP # Resistance (  ) In airin vacuum E E e87.14e11 Back calculation

8 Resistance for (MCP # ) under different conditions in vacuum: Average resistance in vacuum (1.68G  ) P=1.45mbar P=3.7 mbar (3000sccm flowing N2) P=up to 10 mbar (3000sccm flowing N2) No pumping 1.45 mbar (N2 off and evacuation) 1.45 mbar (10 s water pulse) 1.45 mbar (water off and evacuation) 1.45 mbar (high water dose and No pumping) 1.45 mbar (Evacuation after water dose) Back to the Rs= 1.68G  MCP #Resistance In airin vacuum M  1.68G  (40 micron) ALD Chem-2

9 Resistance for (MCP # ) from 1.45 to 985mbar conditions: P=1.45mbar P=985 mbar Air vent Open Slowly Atmospheric pressure  Rs =(~1M  ) (40 micron) ALD Chem-2

Resistance for (MCP # ) from 1.45 to 985mbar conditions: 10 MCP #Resistance In airin vacuum M  415M  Rs vs. Air pressure (40 micron) ALD Chem-2

Resistance for (MCP # ) from 1.45 to 985mbar conditions: 11 MCP #Resistance In airin vacuum M  Equivalent R on 33mm 5 M  Right kind of ALD chemistry Need to tune Rs around this ALD process Question: Will this MCP useful? For 33mm MCPs we do NOT see any major Rs change in Air vs. Vac. Note: All these MCPs tested at UCB Rs data form MCP data base (20 micron) ALD Chem-2

8”x8” MCP resistance summary  Extremely sensitive to moisture  Extremely sensitive to ALD chemistry  Electrode and the hexagonal boundaries in MCP  Initial resistance (in vac.)  Which data we need to consider (Vac. Vs. Air)?  We are building Quick resistance measurement test set-up at ALD lab –Required parts has ordered from MDC –Tentative completion schedule September end 12 Requirements: 20 micron electroded (8”x8”) MCPs Technician helping hand Note: All these achievements for very critical task done with only 5 mixed x (8”x8“) MCPs