Reivindicaciones

1. Method to reduce excess noise in planar electronic devices characterized by the use of a thermodynamic barrier for charge carriers, formed by a screen-layer (2) whose doping is opposed to the doping of the epilayer (4) used to make the devices and an undoped, separating-layer (3) embedded between the devices and the screen-layer (2), all the above grown or placed onto a substrate (1) that can be a semi-insulating substrate or a conducting substrate, being the latter useful as screen-layer if its doping is opposed to the doping of the epilayer (4) used to make the devices. 2. Method to reduce excess noise in planar electronic devices following claim 1<st> , characterized by a low impedance electrical connection of the screen-layer (2) of the aforementioned thermodynamic screen to the Source (6) or to the Gate (5) of the field effect transistors in the epilayer (4) or to one of the Source (6) or Drain (8) ends of the resistors in the epilayer (4), obtained as simplified versions of the aforementioned field effect transistors when the Gate (5) does not exist or when it is connected to one of the ends Source (6) or Drain (8) of the resistor obtained in this way. 3. Use of the method to reduce excess noise described in claims 1<st> and 2<nd> for those devices characterized by a structure comprising an inner conducting channel surrounded by a neighbour conductor that is done by the electrical connection of the surrounding conductor to one of the ends of the inner conducting channel directly, or through a low-impedance circuit allowing an efficient reduction of the amplitude of thermodynamic kT/C noise that would have the capacitance C between the inner channel and the outer conductor before the proposed connection was done.