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DRDO ANNUAL REPORT 2017

Limited Series Production of S-band CCTWT           for technology development. The growth of
                                                    SiC boule from 2 inch to 4 inch diameter has
     One S-band TWT has been made by BEL            been undertaken using PVT reactors installed
during this year as part of LSP. The tube met       at SSPL, Centre for Materials for Electronics
all electrical specifications. One more TWT is      Technology (C-MET) and DMRL. The SiC boule
under assembly. One of these TWTs will be           of 2 inch dia. grown at C-MET were successfully
undergoing QT. This tube has been subjected         cylindrically grinded and cut in to wafers of
to full environment tests successfully.             thickness 500 micron from 15 mm thick ingots
                                                    using recently installed Multiwire Saw Machine
40 GHz Upgradation of Monolithic                    at SSPL. Surface grinding/ polishing of as cut
Microwave Integrated Circuit (MMIC) Facility        SiC wafers was done with the help of outside
                                                    agency having final thickness ~350 micron
     A contract was signed with the MMIC Foundry,   and surface roughness of <5 nm (without
OMMIC France in 2014 to implement and transfer      CMP process). Major technological steps, from
0.5 µ, 0.25 µ and 0.13 µ pHEMT based MMIC           ingot growth to wafer fabrication, have been
technologies at GAETEC, Hyderabad. The              successfully demonstrated.
facilities at GAETEC have been upgraded by
commissioning additional clean room space and                               PVT reactor and multi wire Saw
related utilities. All the unit process modules
for D05PH, D025PH and D01PH pHEMT MMIC              Development of Bismuth Telluride Alloy-
technologies have been implemented. D05 PH          based Nanocomposites for Thermoelectric
model verification has been completed and process   Cooling Applications
demonstrator MMICs fabricated and tested at
GAETEC. Five demonstrator MMICs viz. wide                Optimisation of ball milling parameters to
band SPDT switch with integrated TTL driver,        achieve nano-sized particles for p-type Bi0.5Sb1.5Te3.2
2W X-band power amplifier, 2W millimeter wave       and n-type Bi2Se0.3Te2.7 has been completed.
power amplifier, wide band low noise amplifier      Optimisation of compaction parameters to
and 10W X-band high power amplifier were            maximize density for p-type (86%) and n-type
designed on 0.5 µ, 0.25 µ and 0.13 µ pHEMT-         samples (94%) using 40 Ton auto-press has
based MMIC technologies of OMMIC France,            been completed for samples of 13 mm and
and were subsequently fabricated at OMMIC           20 mm diameter. Nanocomposites (p-type and
France and tested at GAETEC. These five MMICs       n-type) based on nanostructured alloys of
met design specifications. OMMIC France is          Bismuth Telluride and using Si, Cu and SiC
currently in the final stages of implementing the   nanoinclusions have been prepared. Study of
0.5 µ, 0.25 µ and 0.13 µ pHEMT based MMIC           annealing on the thermoelectric properties of
technology processes at GAETEC. Fabrication         the cold-pressed nanocomposites pellets are in
exercises for active and passive device library at
GAETEC for these technologies is in progress.
X-band 13 W MMICs were delivered to LRDE
and 2-W Ka-band MMICs were fabricated and
delivered to SAC. Designs of Ku-band MMICs
have been completed and are under fabrication.

Silicon Carbide Single Crystal Bulk Growth
Process Development and Fabrication of
Wafers

     A new clean room lab space as per the
requirement has been created where ‘PVT
reactor’ for the growth of SiC single crystal
boule and ‘Diamond Multi-wire Saw Machine’
for the slicing of SiC wafers have been installed

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