Xing Sheng, EE@Tsinghua Principles of Micro- and Nanofabrication for Electronic and Photonic Devices Packaging and Integration Xing Sheng 盛 兴 Department of Electronic Engineering Tsinghua University [email protected] 1 Xing Sheng, EE@Tsinghua Packaging Si wafers IC chips Video 3 Xing Sheng, EE@Tsinghua Packaging Si wafers IC chips test, wafer thinning, dicing, bonding, ... 4 Xing Sheng, EE@Tsinghua Probe Test 5 Xing Sheng, EE@Tsinghua Wafer Thinning typically, ~100 m can be as thin as 20 m 6 Xing Sheng, EE@Tsinghua Wafer Thinning 7 Xing Sheng, EE@Tsinghua Dicing laser saw plasma ... 8 Xing Sheng, EE@Tsinghua Wire Bonding 9 Xing Sheng, EE@Tsinghua 'Flip-Chip' Die Bonding Metals alloys: Pb, Cu, Ag, Sn, ... low melting point 10 Xing Sheng, EE@Tsinghua Eutectic Bonding Au Si 11 Xing Sheng, EE@Tsinghua Infrared Imaging Si is transparent at near-infrared (> 1100 nm) 12 Xing Sheng, EE@Tsinghua Through-Silicon Via (TSV) Conductive channels through the silicon wafer 13 Xing Sheng, EE@Tsinghua Through-Silicon Via (TSV) Conductive channels through the silicon wafer 14 Xing Sheng, EE@Tsinghua Silicon Interposer A conductive interface between chips and substrates interposer Q: Why shall we use Si? 15 Xing Sheng, EE@Tsinghua Memory Chips . Increase the memory volume by 3D chip stacks 16 Xing Sheng, EE@Tsinghua 2D -> 2.5D - 3D reduced size, faster speed, higher performance, ... Video 17 Xing Sheng, EE@Tsinghua 3D IC . Logic + Memory + Sensing + ... conventional 3D IC M. M. Shulaker, et al., Nature 547, 74 (2017) 18 Xing Sheng, EE@Tsinghua Chip Packaging Q: Why is the package black? 19 Xing Sheng, EE@Tsinghua X-ray Inspection of Circuit X-ray image 20 Xing Sheng, EE@Tsinghua X-ray Inspection of Circuit M. Holler. et al., Nature 543, 402 (2017) 21 Xing Sheng, EE@Tsinghua Wafer Bonding when direct growth is difficult ... Si SiO2 Si 22 Xing Sheng, EE@Tsinghua Wafer Bonding . Direct wafer-wafer bonding very clean and smooth surface o high temperature (> 1000 C) for atom diffusion Si SiO2 Si 23 Xing Sheng, EE@Tsinghua Wafer Bonding . Direct bonding . Surface activated bonding . Plasma activated bonding . Anodic bonding . Eutectic bonding . Glass frit bonding . Adhesive bonding . Thermocompression bonding . Reactive bonding . Transient liquid phase diffusion bonding . ... https://en.wikipedia.org/wiki/Wafer_bonding 24 Xing Sheng, EE@Tsinghua Wafer Bonding: Applications 25 Xing Sheng, EE@Tsinghua Make Silicon-on-Insulator (SOI) Bonding + Etch back 26 Xing Sheng, EE@Tsinghua Make Silicon-on-Insulator (SOI) 'Smart-Cut' 27 Xing Sheng, EE@Tsinghua MEMS . Micro-Electro-Mechanical Systems (MEMS) Digital Micromirror Device (DMD) Video 28 Xing Sheng, EE@Tsinghua MEMS 29 Xing Sheng, EE@Tsinghua III-V Lasers on Si 30 Xing Sheng, EE@Tsinghua Multijunction (MJ) Solar Cells Eg1 Eg2 Eg3 solar spectrum e- 1.5 (AM1.5G) e- /nm) 2 1.0 0.5 h+ h+ h+ Power Power (W/m 1J: = 37% 0.0 500 1000 1500 2000 2J: = 50% Wavelength (nm) 3J: = 56% ASTM G173-03 infinite J: = 72% Use the entire solar spectrum W. Shockley and H. A. Queisser, J. Appl. Phys. 32, 510 (1961) C. H. Henry, J. Appl. Phys. 51, 4494 (1980) 31 Xing Sheng, EE@Tsinghua Stacked MJ Solar Cells bonded AlGaInP/GaAs // GaInAsP/GaInAs solar cells GaAs GaInAs AlGaInP GaInAsP World record efficiency: 46% F. Dimroth, et al., IEEE J. Photovolt. 6, 343 (2016) 32 Xing Sheng, EE@Tsinghua UV and IR Imaging Sensors . Silicon only absorbs well from 400 nm to 1100 nm . IR sensors: InGaAs, HgCdTe, ... UV sensors: GaN, ... sensor arrays bonded with Si circuits infrared imaging T. Shuto, et al., Jpn. J. App. Phys. 53, 04EB01 (2014) 33 Xing Sheng, EE@Tsinghua Red LEDs . AlGaInP red LEDs grown on GaAs substrates . GaAs strongly absorbs red light . GaP is transparent in red, but not lattice matched . bond LEDs on GaP, and remove GaAs F. A. Kish, et al., App. Phys. Lett. 64, 2839 (1994) 34 Xing Sheng, EE@Tsinghua Blue LEDs . GaN blue LEDs grown on sapphire substrates . Sapphire is electrically and thermally insulating . bonded onto a thermally conductive substrate 35.