ALD Fiji for Conformality Test EE412 ALD Fiji for Conformality Test Insun Park & Young Ik Son Mentor: J Provine 10/04/2011

Motivation ALD Fiji is capable of forming highly conformal metal films on various topologies, but it has not been fully characterized Grating Light Valve(GLV) vertical interconnects have deep trench and spherical structure which is good to test the ALD Fiji coverage test.

GLV Vertical Interconnect Similar to GOPHER process DRIE  isotropic etch Conformal coating with oxide and metal Thermo-compression bonding Goal for EE412 !!

GLV vertical interconnect Fabrication process Starting from regular Si wafer, thermal oxidation and transfer pattern from resist to oxide hard mask(Mask 1) 1st DRIE on the order of 100um 50~ 100um 1~5 um 9/19/2011 GLV vertical interconnect

GLV vertical interconnect Fabrication process Cover the etch holes with oxide for a sidewall protection Remove oxide in the bottom of hole for a further etch 9/19/2011 GLV vertical interconnect

GLV vertical interconnect Fabrication process Further etch by 2nd DRIE Isotropic Si etch 1~5 um 2~20 um 9/19/2011 GLV vertical interconnect

GLV vertical interconnect Fabrication process Cover the spheres conformally with oxide ALD seeding layer (alumina) if necessary and Pt layer - 9/19/2011 GLV vertical interconnect

5.6 um hole : 51 um depth after 1st DRIE 9/19/2011 GLV vertical interconnect

5.6 um hole after isotropic Si etch 9/19/2011 GLV vertical interconnect

Experimental Parameters Seeding Layer Alumina Thermal silicon oxide Plasma ALD Thermal ALD Things to measure Conformallity (nucleation issue) Thickness (SEM, XRD) Resistance Trade-off Plasma: less dependence on substrate Thermal: better coverage

Equipment List Thermal Oxidation: tylan 1&2 Photolitho: ASML, Karlsus 1&2 Etch: P5000, amtetcher, drytek2, Xactix, STS2 Characterization : SEM @SNL, SNC & SNF, XRD ALD Deposition : savanah, fiji Test mask

Time Line Week 1~2 Week 3 ~ 6 Week 6 ~ 8 Week 9 ~ 10 Project proposal, fabrication outline Week 3 ~ 6 Equipment training Structure Design(mask) and Fabrication Plasma/thermal ALD Pt film characterization on SiO2 Week 6 ~ 8 Plasma/thermal ALD Pt film characterization on Al2O3 Week 9 ~ 10 Presentation, SNF Wiki Update