US 12,243,926 B2
HEMT transistor with improved gate arrangement
Gokhan Atmaca, Grenoble (FR)
Assigned to COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Filed by COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES, Paris (FR)
Filed on Dec. 29, 2021, as Appl. No. 17/564,831.
Claims priority of application No. 21305017 (EP), filed on Jan. 7, 2021.
Prior Publication US 2022/0216320 A1, Jul. 7, 2022
Int. Cl. H01L 29/47 (2006.01); H01L 29/20 (2006.01); H01L 29/205 (2006.01); H01L 29/778 (2006.01)
CPC H01L 29/475 (2013.01) [H01L 29/2003 (2013.01); H01L 29/205 (2013.01); H01L 29/7786 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A normally off field-effect transistor of High Electron Mobility Transistor (HEMT) type, comprising:
a source electrode,
a drain electrode,
a channel region formed in a semiconductor block, said semiconductor block being provided with an hetero-structure and comprising at least a first semiconductor layer of a first semiconductor material having a first band gap and a second semiconductor layer of a second semiconductor material having a second band gap, and
a conductive gate to control a current flow between the source electrode and the drain electrode, the conductive gate being composed of a metallic upper region contacting a lower semi-conductor region, said lower semiconductor region being formed of:
a first sub-region that is P-type and in contact with said upper region,
a second sub-region that is P-type and in contact with said second layer, and
an intermediate sub-region arranged between said first sub-region and said second sub-region, said intermediate sub-region being P-doped with a concentration of dopants being lower than 1*1017 cm−3 and being 1000 times lower than that of said first sub-region and the second sub-region, respectively.