Title :
Si/Si/sub 1-x-y/GexCy/Si heterojunction bipolar transistors
Author :
Lanzerotti, L.D. ; Amour, A. St ; Liu, C.W. ; Sturm, J.C. ; Watanabe, J.K. ; Theodore, N.D.
Author_Institution :
Dept. of Electr. Eng., Princeton Univ., NJ, USA
fDate :
7/1/1996 12:00:00 AM
Abstract :
We report the first Si/Si/sub 1-x-y/Ge/sub x/C/sub y//Si n-p-n heterojunction bipolar transistors and the first electrical bandgap measurements of strained Si/sub 1-x-y/Ge/sub x/C/sub y/ on Si (100) substrates. The carbon compositions were measured by the shift between the Si/sub 1-x-y/Ge/sub x/C/sub y/ and Si/sub 1-x/Ge/sub x/ X-ray diffraction peaks. The temperature dependence of the HBT collector current demonstrates that carbon causes a shift in bandgap of +26 meV/%C for germanium fractions of x=0.2 and x=0.25. These results show that carbon reduces the strain in Si/sub 1-x/Ge/sub x/ at a faster rate than it increases the bandgap (compared to reducing x in Si/sub 1-x/Ge/sub x/), so that a Si/sub 1-x-y/Ge/sub x/C/sub y/ film will have less strain than a Si/sub 1-x/Ge/sub x/ film with the same bandgap.
Keywords :
Ge-Si alloys; elemental semiconductors; energy gap; heterojunction bipolar transistors; molecular beam epitaxial growth; semiconductor materials; silicon; C compositions; HBT collector current; MBE; Si; Si (100) substrates; Si-SiGeC-Si; Si/Si/sub 1-x-y/Ge/sub x/C/sub y//Si HBT; electrical bandgap measurements; heterojunction bipolar transistors; n-p-n HBT; strained Si/sub 1-x-y/Ge/sub x/C/sub y/; temperature dependence; Atomic layer deposition; Atomic measurements; Capacitive sensors; Electric variables measurement; Germanium; Heterojunction bipolar transistors; Photonic band gap; Substrates; Temperature dependence; X-ray diffraction;
Journal_Title :
Electron Device Letters, IEEE
