What Substrates Are Used to Fabricate mmWave Devices?

We are looking for silicon wafers with very high resistivity (float zone) for millimeter-wave applications (up to 110 GHz). That is why a 30 kohm-cm is required in order to keep the loss tangent as low as possible. It is not possible to use another diameter because of the dimensions of our RF circuits.

Do you have in stock any intrinsic silicon wafer with a thickness between 450-475um and 3 or 4 inches in diameter?

After reading in some scientific publications, people who used your silicon wafer have reported a carrier recombination time of about 10ns, which is considerably less compared to silicon wafers offered by other companies. This recombination time is suitable for my experiment. Is this time value still valid in the silicon wafer that you currently offer?. Besides, do you have any information about the carrier recombination time in gold-implanted germanium (Ge:Au) and gold-implanted silicon (Si:Au)?

Actually it is one publication that mention your name:

"Laser-driven semiconductor switch for generating nanosecond pulses from a megawatt gyrotron"and in the following one, they don't mention it, but I am pretty sure they used one of your silicon wafers because they used a similar wafer to the above publication with similar results:

"Experimental demonstration of externally driven millimeter-wave particle accelerator structure"

I am interested in knowing wheter you sell or can provide GaAs wafers of 100um thick. The reason I ask for this ultra-thin wafers is due to the ultra high frequency applications intended for (up to 300GHz). As you may well know parasitics can appear/surface waves/higher order modes, once the overall thickness reaches quarter wavelength. This is why I am interested in 100 microns thick GaAs wafers.

Do you sell/can provide such thin substrates of 100 microns thick GaAs wafers? The diameter of the wafer can range between 3"-5".

We would really need 100µm thick GaAs substrates and I will explain why: 

The general rule when designing mmwave/submmwave circuits is to use a laminate/wafer that is thinner than one-quarter wavelength at an application’s highest operating frequency. This is because once this quarter wavelength substrate thickness barrier is reached, unwanted resonances/surface waves/parasitic higher order modes can take control over the desired mode of propagation.

What we have designed and want to fabricate are circuits (mostly some bandpass filters) that have central frequency f_c=240GHz, 270GHz. This means that max freq of operation should be at least f_c. 

For a GaAs 150µm substrate, for f=190GHz, substrate height=quarter wavelength, so theoretically this would be f_max. 

That is why with a substrate height of 100µm we can reach f_max of aprox. 300 GHz,which falls beyond our operation frequencies. As such we can avoid resonances and other unwanted modes within the fundamental CPW propagation environment.

We would really need a substrate height of aprox. 100µm because of the reasons aforementioned. Or if not, we could try and manage with 125µm, but 100µm is what we would need. 

If not, what about 2" wafers? Can you provide GaAs 100µm thick on 2" ?

I am interested in using a single-crystal quartz plate as a millimeter-wave half-wave plate. 

I believe we would want X-cut for birefringence in the millimeter-waves, at least according to section IIIa in this reference: http://adsabs.harvard.edu/abs/1986ITMTT..34..932D

The thickness and diameter we want for the plate is large, 21.91 mm thick, and an OD of 330 mm would be ideal. Is this something your company can do? If so, we would order one initially for testing, and if it works we would need 6-10 more for our application.

We are looking for the ultrathin quartz wafer for fabrication of ultra-low loss  thin-film passive millimeter-wave circuit recently. All the domestic vendor in Taiwan cannot fulfill our requirement. I saw your company provide the wafer which meet our need, but the shipping is a problem. Are you able to provide the products shipping outside north america with good final condition?

We are interested on the U01-120627-1, with diameter 25.4mm and 0.05mm thickness, Z-cut preferred.