The name is absent

53

the cable connectors after wire-bonding may easily cause damage to the SLM chip.
We prefer cutting groves into the workholder, and will discuss the procedural details
with Nicholas Moses from VLSIP.

Future work involves investigation of the causes for the low modulation depth of
the SLM pixels and the reasons for the fabrication defects. Measuring the doping
density of the residual pieces of the wafer, on which our SLMs are fabricated, can
ensure that the n-doped GaAs layer provide enough modulation. The next attempt
to fabricate and package the THz SLM samples should avoid similar problems.

(a) Defect locations on SLM 1

Figure 5.8 : (a) Locations of defects on SLM 1 observed under the microscope (see
lines sketched on mask), (b) An 32×32 image of the modulation depth of the pixels
on SLM 1, overlaid with sketches of defects in (a). At 0.37 THz, the SLM pro-
vides around 20% amplitude modulation at the darker regions on the image, and has
zero modulation at the brighter regions. The defects cut off some SLM pixels from
their Schottky pads, thus the SLM cannot provide any amplitude modulation at the
corresponding pixel locations.

(b) Modulation depth image of SLM 1

<<   68   69   70   71   72   73   74   >>

More intriguing information