Status and Results of ALD Microchannel Plate Program Qing Peng, Anil U. Mane, Jeffery W. Elam LAPD Collaboration Meeting October 15th, 2009,

Proposed Experiment Procedure ALD resistive layer MCP ALD Secondary emission layer Electrode layer

Status of ALD MCP Program MCPs coated by ALD and Evap have been fabricated Mercury probe and picoammeter for resistivity measurement has been setup Samples for SEE measurement provided for characterization, more sample will be provided New recipes for resistive layer and SEE layer are proposed and ready to try Sample holder for electrode deposition has been made Process for electrode deposition is established Uncoated MCP MCP 100nm AZO/ 5nm Al2O3 MCP+100nm AZO+Cr 5nm+Au 50nm

Resistive Layer With Al doped ZnO by H2O Chemistry Concerns: 1) Resistivity change dramatically with doped ratio at interested range 2) OH and carbon contamination in film

O3 based Chemistry for Al2O3, ZnO and Al doped ZnO (AZO) Al2O3 ALD film by O3 Better electronic properties than H2O chemistry Less carbon and –OH contamination Less defect of Al-Al bonding ZnO ALD film by O3 Better electronic properties Less carbon and OH contamination Potential benefits: Better stable resistivity Better SEE properties Stable properties during future process

In-situ Growth Monitor of Al2O3 by O3 with TMA TMA WITH O3 122 200 Growth rate (Å) Growth rate (Å) 120 190 3600 3800 4000 2540 2560 Time (s) Time (s) Self-limiting conformal growth Al2O3 by TMA and O3 Trimethyl Aluminum (TMA)

In-situ Growth Monitor of ZnO by O3 with DEZ DEZ WITH O3 Growth rate (Å) Growth rate (Å) Time (s) Time (s) Self-limiting conformal growth ZnO by DEZ and O3 Diethyl Zinc (DEZ)

In-situ Growth Monitor of Al doped ZnO by O3 AZO WITH O3 20% Al cycle Growth rate (Å) Growth rate (Å) Time (s) Time (s) The growth behavior of Al doped ZnO by DEZ/O3 AND TMA/O3, Etching observed during TMA dose.

Aluminum doped Zinc Oxide (AZO) growth rate at different conditions 20% ALO cycle H2O chemistry, 177C H2O chemistry, 200 C O3 chemistry, 200 C Diethyl Zinc Trimethyl Aluminum Results: 1) At 200C, with O3 chemistry AZO growth rate is smaller than the growth rate with H2O chemistry for same cycle conditions. 2) For H2O chemistry, AZO growth rate is smaller at 200C than at 177C

Future Work Optimize resistive layer coating Systematic study of ALD process for AZO for the optimal resistance Chemistry Temperature Dope ratio Automatic measuring system for resistance during deposition In-situ monitor the deposition process Optimize SEE layer coating More samples with different properties for SEE test More MCP sample with different properties for SEE test Optimize the electrode coating process Ni/Cr Ti/Au

THANKS!