Patent EP-3158584-A1 (EP)
Inventor: PALMA FABRIZIO
IPC: H01L27/144
Filed: 2015-06-19
Abstract: The present invention relates to a rectifier for a sensor of electromagnetic signal, said electromagnetic signal having a frequency between 300Ghz and 10THz. Said rectifier comprising: - a semiconductor substrate (1 ) doped p/n comprising a electrons/holes gathering well (2) for gathering electrons/holes; said electrons/holes gathering well (2) being arranged inside said semiconductor substrate (1 ) and comprising at least a first zone doped n/p (21 ); said first zone doped n/p (21 ) having an end surface (21 A); - a metal end surface (41 ) of an antenna (4), said antenna being capable of receiving and concentrating said electromagnetic signal; - a layer doped p/n (3) having a first surface (31) and a second surface (32), opposite to said first surface (31 ). In particular, a first portion of said first surface (31) of said layer doped p/n (3) is in contact with said end surface (21 A) of said first zone doped n/p (21 ) of the electrons/holes gathering well (2), so as to form a first metallurgical junction (G1 ), and a first portion of said second surface (32) of said layer doped p/n (3) is in contact with said metal end surface (41 ), so as to form a second metallurgical junction (G2). The concentration of the doping of said layer doped p/n (3) and the concentration of the doping of said first zone doped n/p (21) of said electrons/holes gathering well (2) are such that said first metallurgical junction (G1) has a first potential barrier (V Z1 ) inside and the work function of the metal of said metal end surface (41 ) is selected such that it is equal to that of a semiconductor doped n/p and such that said second metallurgical junction (G2) has a second potential barrier (V zz ) inside. Said first metallurgical junction (G1 ) and said second metallurgical junction (G2) form a double metallurgical junction n-p-n/p-n-p with a double potential barrier composed of said first potential barrier (V z1 ) and said second potential barrier (Vz2), where said double metallurgical junction n-p-n/p-n-p comprises a first depletion zone (Z1 ), and a second depletion zone (Z2), in contact with said first depletion zone (Z1 ) along a line of contact (A), disposed within said layer doped p/n (3), said first depletion zone (Z1 ) having a thickness greater than the thickness of the second depletion zone (Z2); said first potential barrier (Vzi) being associated with said first depletion zone (Z 1 ), and said second potential barrier (Vz2) being associated with said second depletion zone (Z2). Said layer doped p/n (3) is dimensioned in such a way that said double potential barrier has a value such as to allow said layer doped p/n (3) being completely deprived of holes/electrons, so that, when a variable electric field is induced by said electromagnetic signal received by said antenna (4), said double metallurgical junction n-p-n/p-n-p is subjected to said variable electric field, and a first potential difference (AV^) and a second potential difference (AV Z2 ) are generated, through the first depletion zone (Z1 ) and through the second depletion zone ( Z2 ) respectively, where each potential difference (ΔVzi, ΔVz2) is proportional to the thickness of the respective depletion zone (Z1, Z2) and is added algebraically to the respective potential barrier (V z1 , V z2 ). The present invention relates also to a charge gathering system comprising said rectifier.