Alan Mantooth, Carl-Mikael Zetterling and Ana Rusu (28 April 2021)
"The Radio We Could Send to Hell: Silicon carbide radio circuits can
take the volcanic heat of Venus" IEEE Spectrum
https://spectrum.ieee.org/semiconductors/materials/the-radio-we-could-send-to-hell
"The average surface temperature on Venus is 464 °C, the atmosphere is
dense with highly corrosive droplets of sulfuric acid, and the
atmospheric pressure at the surface is about 90 times that of Earth."
(Teflon melts at 327 °C)
The following thesis describes the Vulcan II chip mentioned a bit more
Benavides Herrera, Maria Raquel, "An RS-485 Transceiver in a Silicon
Carbide CMOS Process" (2018).Theses and Dissertations 3067
"The RS–485 was designed in a 1.2 μm SiC CMOS process technology
developed by
Raytheon Systems Limited (UK) called High Temperature Silicon Carbide
(HiTSiC®).
The components available in this process include: NMOS and PMOS devices,
on-chip resistors, diodes, and capacitors.
The process key features are given below:
• 4H-SiC process
• N-type substrate
• Supply voltage of 15 V
5• Single metal layer, two layers of polysilicon (one being high sheet
resistance poly)
• Operating temperatures greater than 300°C" ...
---
In 1988's 1.2μm CMOS process the MIPS R3010 floating-point coprocessor
was about
75,000 transistors on an ~8mm x 8mm die.
Are there markets for SiC CMOS devices with large transistor counts?
Watching Curious Marc's video mentioning Triton missile/Saturn V bit-serial
computer implementations, reminded me of:
Olof Kindgren (2019) Bit by bit - How to fit 8 RISC-V cores in a $38
FPGA board
https://riscv.org/wp-content/uploads/2019/06/12.15-SERV-Zurich-Copy.pdf
https://github.com/olofk/serv "SERV is an award-winning bit-serial
RISC-V core" (RV32I)
(Not an engineer - guessing)
If process limits mean large SiC memories are unlikely, what other
technologies
would work in the 400–500°C temperature range? Magnetic bubble memory?
Twistors
if threading cores automatically remains infeasible?
For cameras could you build vacuum tube sensors containing SiC devices
if useful?
