Fet charge sensor and voltage probe

Claim 2

A voltage/charge sensor device for accumulating charges to be measured in an electric field, said sensor comprising a first field effect transistor structure having a passivating overlay, a biased metal gate electrode and an inducible conducting channel between source-to-drain electrodes; and a first modulating means accumulating a charge to be measured for modulating the source-to-drain conductivity in accordance with the charges that are accumulated; said modulating means characterized by including a first insulating layer that is a multiple of thicknesses greater than said passivating layer; and said first layer surrounding only said metal gate electrode and also coming into contact with said conductive channel.

Claim 3

The sensor device of claim 1 and further comprising: at least a second field effect transistor structure like the first and having a passivating overlay, a biased metal gate electrode and an inducible conducting channel between source-to-drain electrodes; a second modulating means accumulating a charge to be measured for modulating the source-to-drain conductivity of said second transistor in accordance with the charges that are accumulated; said second modulating means characterized by including a second insulating layer that is a multiple of thicknesses greater than said passivating overlay of said second field effect transistor; said second layer surrounding only said second gate electrode and also coming into contact with said second conductive channel; means forming a particle spectrometer by spacing and maintaining said second transistor structure being separate and apart from said first transistor structure and positioned one above the other.

Claim 4

The sensor device of claim 1 wherein each transistor structure has connected thereto means for sampling the channel conductivity to provide a measure of the accumulated charge.

Claim 5

The sensor device of claim 1 wherein said gate is biased in the enhancement mode.

Claim 6

The sensor device of claim 1 wherein said gate is biased in the depletion mode.

Claim 7

The sensor device of claim 2 wherein each transistor structure has connected thereto means for sampling the channel conductivity to provide a measure of the accumulated charge.

Claim 8

A plurality of voltage/charge sensor devices stacked one over each other to form a particle spectrometer and comprising a first voltage/charge sensor device located at an upper layer of said stack, and including a first field effect transistor structure having a passivating overlay, a biased aluminum gate electrode and a first inducible conducting channel between source-to-drain electrodes; and a first modulating means accumulating a low-energy charge to be measured for modulating the source-to-drain conductivity in accordance with the low-energy charges that is accumulated; said first modulating means characterized by including a first insulating layer that is a multiple of thicknesses greater than said passivating layer; said first insulating layer surrounding only said aluminum gate electrode and also coming into contact with said first conductive channel; a second voltage/charge sensor device located under said first in said stack, and including a second field effect transistor structure having a passivating overlay, a biased iron gate electrode and a second inducible conducting channel between source-to-drain electrodes; a second modulating means accumulating a medium-energy charge to be measured for modulating the source-to-drain conductivity of said second transistor in accordance with the medium-energy charge that is accumulated; said second modulating means characterized by including a second insulating layer that is a multiple of thicknesses greater than said passivating overlay of said second field effect transistor; aid second layer surrounding only said iron gate electrode and also coming into contact with said second conductive channel; a third voltage/charge sensor located as a third layer of said stack, and including a third field effect transistor structure having a passivating overlay A biased gold gate electrode and a third inducible comducting channel between source-to-drain electrodes; and a third modulating means identical to said first or second modulating means for accumulating high-energy charge to be measured for modulating the source-to-drain conductivity of said third transistor in accordance with the high-energy charge that is accumulated.

Claim 9

A plurality of voltage/charge sensor devices stacked one over each other to form a particle spectrometer and comprising a first voltage/charge sensor device located at an upper layer of said stack, and including a first field effect transistor structure having a passivating overlay, a biased aluminum gate electrode and a first inducible conducting channel between source-to-drain electrodes; and a first modulating means accumulating a low-energy charge to be measured for modulating the source-to-drain conductivity in accordance with the low-energy charges that is accumulated; said first modulating means characterized by including a first insulating layer that is a multiple of thicknesses greater than said passivating layer; said first insulating layer surrounding only said aluminum gate electrode and also coming into contact with said first conductive channel; a second voltage/charge sensor device located under said first in said stack, and including a second field effect transistor structure having a passivating overlay, a biased iron gate electrode and a second inducible conducting channel between source-to-drain electrodes; a second modulating means accumulating a medium-energy charge to be measured for modulating the source-to-drain conductivity of said second transistor in accordance with the medium-energy charge that is accumulated; said second modulating means characterized by including a second insulating layer that is a multiple of thicknesses greater than said passivating overlay of said second field effect transistor; aid second layer surrounding only said iron gate electrode and also coming into contact with said second conductive channel; a third voltage/charge sensor located as a third layer of said stack, and including a third field effect transistor structure having a passivating overlay A biased gold gate electrode and a third inducible comducting channel between source-to-drain electrodes; and a third modulating means identical to said first or second modulating means for accumulating high-energy charge to be measured for modulating the source-to-drain conductivity of said third transistor in accordance with the high-energy charge that is accumulated.

Claim 10

The particle spectrometer of claim 7 wherein each transistor structure further comprises in combination means for sampling the channel conductivity to provide a measure of the low, medium and high energy charges accumulated by said first, second and third modulating means.