Microwave Devices Microwave Semiconductor Devices 1 2008 1

Microwave Devices - Microwave Semiconductor Devices - 1 2008 / 1 학기 서광석 • S. N. U. EE Microwave Devices 2008

Compound Semiconductor 사용의 장점 다양한 반도체의 존재로 인해 응용에 적합한 재료 선택 가능 n (예) 광소자의 파장 조절 : Ga. As, Ga. P, In. Ga. Al. N 등 n (예) 고온 동작용 반도체 : wide-bandgap semiconductor 선택 초고속 동작에 적합한 반도체 재료 사용 가능 n High mobility & carrier velocity short carrier transit time 다양한 반도체 재료들의 동시 사용을 통해 소자 성능 개선 heterostructure devices : heterostructure FET, heterostructure bipolar Tr. bandgap의 차이를 활용한 bandgap engineering을 통한 new devices EC eee Eg 1 EV • S. N. U. EE Potential Well (Quantum Well)을 h 활용한 발광 - 효율적인 전자와 hole의 재결합 - 전하와 빛의 confinement - 발광 효율 개선 hhh Microwave Devices 2008

Various III-V Semiconductors - 1. 55 μm 광통신 - 초고속 시스템 • S. N. U. EE * In. As/Ga. Sb/Al. Sb heterostructure System * In. P/In 0. 53 Ga. As/In 0. 52 Al. As/Ga. As 0. 5 Sb/Al. As. Sb Microwave Devices 2008

Wurtzite Ga. N, In. N, and Al. N • S. N. U. EE Microwave Devices 2008

Lattice Structure of Basic Semiconductors ( I ) 2 FCC (Face Centered Cubic) cells – separation (a/4, a/4) Diamond Structure; (example) Si - 1 Si FCC cell + 1 Si FCC cell Zincblende Structure; (example) Ga. As - 1 Ga FCC cell + 1 As FCC cell a/2 Diamond Structure ex) Si, Ge, C … • S. N. U. EE Zincblende Structure ex) Ga. As, Ga. P … 3 -5 Microwave Devices 2008

Lattice Structure of Basic Semiconductors ( II ) Wurtzite Structure ex) Ga. N, Cd. S, Zn. S … 2 -6 • S. N. U. EE Rock-salt Structure ex) Pb. S, Pb. Te … 4 -6 Microwave Devices 2008

Ref. - Optical Interconnections ( I ) < EC Nanotechnology Roadmap, 99 > Optical Waveguides Optical Detectors Spin Devices Al. Ga. As/Ga. As GRINSCH QW Lasers on Si CMOS / Bi. CMOS Optical Modulators RTD + Functional devices RF Components Si or SOI Sub. Fiber Optics • S. N. U. EE Molecular Electronics Approach of Amberwave System Corp. Microwave Devices 2008

Ref. - Optical Interconnections ( II ) < Optical Motherboard > - Optical packaging < Compound Semiconductors Materials for LEDs > • S. N. U. EE Microwave Devices 2008

In. As-Channel HEMTs for Ultra-High f. T Devices ABCS In. As/Al. Sb HEMT Structure In. As/Al. Sb HEMTs High In content In. Ga. As/In. Al. As HEMT In. As/Al. Sb HEMT Structure (Ga. As sub) High [Ultra-High Speed/Ultra-Low-power Operation • S. N. U. EE In. P-based HEMTs Ga. As-based HEMTs Microwave Devices 2008

III-V FET for beyond-CMOS Technology IMEC (for 32 nm node and beyond) - Ge PMOS - III-V FET for n-channel - Ge/III-V epitaxy on Si Intel - In. Sb FET for n-channel IBM, Intel & MIT, SNU - In. Ga. As FET for n-channel - Ge FET for p-channel Freescale - Ga. As on GOI for n-channel - In. As, In. Sb based MOSFET on Si D. K. Sadana, IBM, III-V Substrate Eng, Dec. 4, 2005 – SEMATECH Special Meeting • S. N. U. EE Microwave Devices 2008

CMOS-like III-V Logic based on Sb-compounds In. As-Al. Ga. Sb HEMTs (n-channel) Ga. Sb-Al. Ga. Sb HEMTs (p-channel) Ga. Sb cap Al 0. 5 Ga 0. 5 Sb In. As channel Al 0. 5 Ga 0. 5 Sb Ga. Sb channel Al 0. 5 Ga 0. 5 Sb Al. Sb buffer Semi-insulating Ga. As substrate (proposed by Prof. Wang’s group) • S. N. U. EE Microwave Devices 2008

Ga. As Band구조 구조 Ga. As의 의 Energy Band * conduction band - 6, L 6, X 6 valley • Intra-valley Scattering • Inter-band Scattering • S. N. U. EE Microwave Devices 2008

Inter-valley Transfer in Ga. As Conduction Band L valley • S. N. U. EE E=0. 29 e. V valley E=0. 29 e. V Microwave Devices 2008

Compound Semiconductor의 전기적 특성 negative differential resistance - Ballistic Transport - Velocity Overshoot 전자의 effective mass 1/Eg • S. N. U. EE Breakdown Field Eg Microwave Devices 2008

v-E Characteristics of In. Ga. As - Monte Carlo Calculation (Hess) : Unstrained In. Ga. As • S. N. U. EE Microwave Devices 2008

• Band-edge Lineup of Heterojunctions (I) ECA EC Eg. B Eg. A * Electron-Affinity Rule EC Alx. Ga 1 -x. As/Ga. As < 실험적 측정 > Ec ~ 0. 6 Eg Ev ~ 0. 4 Eg EVB EV EVA Vacuum Level ECB ( Classical theory ) Ec = q( B- A) 에 의하면 Ec ~ 0. 85 Eg q A Vacuum Level q B Work function q EC EF EV 실제 값과 차이가 나는 원인 ; interface 효과에 의해 EC 변화 - atom의 rearrangement - wave function들의 interaction. * Ref, “Electronic Materials Science” • S. N. U. EE ( Ch. 14. 4 ) Microwave Devices 2008

• Band-edge Lineup of Heterojunctions (II) Al. Ga. As/Ga. As In. P/In 0. 52 Al 0. 48 P In. As/Ga. Sb In. Ga. As/Ga. Sb. As Ga. Sb/Al. Sb Alx. In 1 -x. As/In. P Ga. As/Ga. P • S. N. U. EE Microwave Devices 2008

• Band-edge Lineup of Heterojunctions (III) • S. N. U. EE Microwave Devices 2008

Al. Ga. As Lattice-Matched to Ga. As Substrate Industry Standard - 6 inch Ga. As wafer - 4 inch In. P wafer bowing parameter C • S. N. U. EE Microwave Devices 2008

Wide Bandgap Materials for High Power RF Devices • S. N. U. EE Microwave Devices 2008

Wide Bandgap Materials – Ga. N/Si. C • S. N. U. EE Microwave Devices 2008

Ga. N Compound Semiconductor의 전기적 특성 • S. N. U. EE material peak (107 cm/s) In. N 4. 2 Ga. N 2. 9 Al. N 1. 7 Ga. As 1. 6 Microwave Devices 2008

Nitride-based Compound Semiconductor Materials <Ga. N 계열 compound semiconductors> * substrate for Ga. N/In. N/Al. N - Al 2 O 3 (lattice mismatched) Si. C (lattice mismatched) Ga. N (lattice matched) : difficult to grow • S. N. U. EE Microwave Devices 2008

Various Substrate for Ga. N Power Amplifiers NGST, 4 mil thinning & grounded vias, Si. C Substrate • S. N. U. EE Microwave Devices 2008