Codoping effects of the Zn acceptor on the structural characteristics and electrical properties of the Ge donor-doped GaN thin films and its heterojunction diodes all made by reactive sputtering
4 years ago
Authors:
Cao Phương Thảo,te,ten
Publication date:
02 / 04 / 2018
Name of Publishers:
Materials Science in Semiconductor Processing
Abstract:
Zn acceptor/Ge donor (Zn/Ge)-codoped GaN films with different Zn contents have been deposited on Si substrates at 300 °C and at 90–150 W by RF reactive sputtering technique with cermet targets at the composition
atomic ratios of Zn:Ge:(Ga+GaN) at x:0.03:(0.97-x) with x = 0, 0.03, 0.06, and 0.09 and Ga:GaN = 3:7. The
films made with such targets were presented in an abbreviated symbol of Zn-x-GeGaN at x = 0, 0.03, 0.06, and
0.09. The morphology, structure, electrical properties, optical property, and hetero-junction diode devices involved in the Zn-x-GeGaN films were thoroughly investigated. The systematic Zn increment into the n-type Zn-0-
GeGaN through property evaluation provides the supporting information in studying solid solutioning. Zn-xGeGaN films converted into p-type semiconductor at x = 0.06 and 0.09. The values of bandgap were in the range
of 2.87–3.17 eV with the lower value for the higher Zn content in Zn-x-GeGaN films. The higher RF power led to
the faster growth, highly deficient in nitrogen, and a higher Zn atom ratio in the deposited film. The 120Wdeposited Zn-0.06-GeGaN film had hole concentration of 7.21 × 1016 cm−3
, hole mobility of 39.1 cm2 V−1 s
−1
,
and the electrical conductivity of 0.45 S/cm.