US 12,224,369 B2
Radiation detector and associated manufacturing method
Axel Evirgen, Palaiseau (FR); Jean-Luc Reverchon, Palaiseau (FR); Michel Garcia, Palaiseau (FR); Olivier Parillaud, Palaiseau (FR); and Bruno Gerard, Palaiseau (FR)
Assigned to THALES, Courbevoie (FR); and COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Appl. No. 17/787,328
Filed by THALES, Courbevoie (FR); and COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
PCT Filed Dec. 17, 2020, PCT No. PCT/EP2020/086687
§ 371(c)(1), (2) Date Jun. 19, 2022,
PCT Pub. No. WO2021/122931, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 1915024 (FR), filed on Dec. 20, 2019.
Prior Publication US 2023/0016835 A1, Jan. 19, 2023
Int. Cl. H01L 31/109 (2006.01); H01L 31/0304 (2006.01); H01L 31/18 (2006.01)
CPC H01L 31/109 (2013.01) [H01L 31/03046 (2013.01); H01L 31/1844 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A radiation detector comprising a stack (Emp) of layers along a direction Z, said stack comprising:
an absorbent layer (Cabs) configured to absorb the radiation and made from a first semiconductor material (M1) having a first gap (G1) and doping of a first type (t1),
a first contact layer (Ccont) made from a second material (M2) having a second gap (G2) strictly greater than the first gap (G1),
an assembly consisting of at least one intermediate layer (Cint, Cinti), referred to as an intermediate assembly (Eint), arranged between the absorbent layer and the first contact layer, each intermediate layer (Cint, Cinti) being made from an intermediate semiconductor material (Mint, Minti) having an intermediate gap (Gint, Ginti) greater than or equal to the first gap (G1),
an upper layer (Csup) arranged on the first contact layer (Ccont) on the opposite side from said intermediate assembly, made from a third semiconductor material (M3) having a third gap (G3) strictly greater than all the other gaps of the stack,
the first contact layer and the upper layer having a plurality of detection zones (Zdet) and separation zones (Zsep), a separation zone separating one detection zone from another detection zone, each detection zone being surrounded by a separation zone in a plane perpendicular to Z, a detection zone corresponding to a pixel of said detector, the second (M2) and third (M3) materials being configured to have doping of a second type (t2) in the detection zones (Zdet) and doping of the first type (t1) in the separation zones (Zsep),
when the first doping type is n, a valence band (BVabs) of the first material (M1) is strictly less than a valence band (BVcont) of the second material (M2) in the detection zones, and the valence band or bands (BVinti) of the intermediate material or materials lie between the valence band (BVabs) of the first material and the valence band (BVcont) of the second material in the detection zones, and are configured to vary monotonically increasingly in the direction from the absorbent layer (Cabs) toward the first contact layer (Ccont),
when the first doping type is p, a conduction band (BCabs) of the first material (M1) is strictly greater than a conduction band (BCcont) of the second material in the detection zones, and the conduction band or bands (BCinti) of the intermediate material or materials (Mint) lie between the conduction band (BCabs) of the first material and the conduction band (BCcont) of the second material in the detection zones, and are configured to vary monotonically decreasingly in the direction from the absorbent layer (Cabs) toward the first contact layer (Ccont),
a passivation layer (Cpass) made from a dielectric material (Mdiel), arranged on the upper layer (Csup) and having openings (Op) at the level of the detection zones of the upper layer,
the semiconductor layers of the stack being compounds based on elements of groups IIIA and VA of the periodic table of the elements, the second material (M2) comprising the VA element antimony (Sb) and the third material (M3) not comprising the VA element antimony (Sb).