PROCESS AND PRODUCTIVITY RESULTS FROM A CARRIER-BASED LINEAR TRANSPORT PVD SYSTEM FOR RDL SEED LAYER DEPOSITION IN FAN-OUT PACKAGING APPLICATIONS

Transcription

1 PROCESS AND PRODUCTIVITY RESULTS FROM A CARRIER-BASED LINEAR TRANSPORT PVD SYSTEM FOR RDL SEED LAYER DEPOSITION IN FAN-OUT PACKAGING APPLICATIONS Paul Werbaneth Intevac, Inc. pwerbaneth@intevac.com

2 PVD Cluster Tool History in Semiconductors Linear Transport Architectures Float Glass Semiconductors Silicon Photovoltaic Cells w/ Carriers PVD Magnetron Architectures Ti and Cu Barrier/Seed Layer Results 300mm Silicon Wafers 600mm x 600mm Glass Panels Cost of Ownership Analysis Conclusions

3 Source (both): R.A. Powell and S.M. Rossnagel, PVD for Microelectronics: Sputter Deposition Applied to Semiconductor Manufacturing, Academic Press, 1999, pp

4 Float Glass Production Process Source: J. Ochshorn, ARCH 2614/5614 Lecture Notes, Cornell University, Jumbo Magnetron Sputtered Vacuum Deposition Glass Coater Source: Ceramic Industry Magazine, February 2017.

5 Conveyor-Based Linear Transport APCVD System for Semiconductor Source: M. Edison, et al., Visual Encyclopedia of Chemical Engineering, University of Michigan, Linear Motion System for In-Vacuum Transport Source: Rexroth / Bosch Group.

6 Carrier-Based Linear Transport Ion Implant System 3000wph Carrier-Based Linear Transport PVD System 3000wph

7 Integrated automation load / unload High throughput (>3000wph) Reliable performance (<0.03% breakage rate) Flexible substrate sizes Integrated, Reliable, High Speed Automation

8 Carrier with One 600mm x 600mm panel Two Carriers with Two 300mm x 300mm panels Two Carriers with Two 300mm wafers

9 Carriers are loaded in atmosphere, a single row at a time to simplify automation Carriers leave vacuum at system exit, which allows for easy change of substrate carriers Substrate size change is done by changing carriers. No in-vacuum changes required Carriers provide structural support Carriers can provide full edge and cross clamping

10 Rotating Magnetron Total Utilization up to 50% Sources: Precision Magtech (above); Gencoa (below) Rotatable Target Magnetron Total Utilization up to 90% Source: BUTTMAN Vacuum

11 Static (Planar) Magnetron Total Utilization 25% to 45% Source: Materials Science, Inc.

12 Linear Scanning Magnet Array (LSMA) High target utilization (>60%) Scanning pole Tunable scan speed High scan acceleration Optimal edge erosion profile Magnet Array Uniform target temperature control enables stable film properties Planar target design beneficial for low target cost and complex materials Magnet array is optimized to the target material High magnet pole strength enables high pass through flux (Magnetic films e.g. Nickel, NiV ) Patented Design, Additional patents filed for use

13 Simple, planar target design beneficial for low target cost and for complex target materials Uniform target temperature control enables stable film properties Magnet array is optimized to the target material Scanning magnet array High speed scan controls redeposition and film uniformity >60% target utilization

14 Scanning Magnetron Total Utilization >60%

15 This is what your article will look like in the magazine. I hope you like it as much as we do. Kind regards, Elaine. Elaine Perrigot, Editor PES Wind & Solar PV

16 Deposit metal(s) of interest onto oxidized silicon wafers or coupons Cleave samples and measure metal thickness with SEM Correlate with Rsheet Film adhesion testing per ASTM D3359-B Results: Ti and Cu films are 1001Å and 2047Å thick Ti Rsheet 6.19Ω/ ±2.6% Cu Rsheet 121mΩ/ ±4.4% Excellent Ti adhesion (ISO/JIS 0 )

17 1 2 Y Ω/sq X1 X 3 4 X2 Y1 Y2 Ti-1 Ti-2 Ti-3 Ti-4 All Average(Ω) Unif. 2.57% 3.26% 3.31% 3.73% 3.73% X & Y X1 X2 Y1 Y2 All Average(Ω) Unif. 2.09% 1.69% 2.51% 3.36% 3.73% Max Min Unif. = Max + Min 17

18 1 2 Y Ω/sq X1 X 3 4 X2 Y1 Y2 Cu-1 Cu-2 Cu-3 Cu-4 All Average(Ω) Unif. 4.37% 3.89% 3.99% 3.41% 4.99% X & Y X1 X2 Y1 Y2 All Average(Ω) Unif. 3.52% 3.61% 2.80% 2.42% 4.99% Max Min Unif. = Max + Min 18

19 1 2 Y Ω/sq X1 X 3 4 X2 Y1 Y2 TiCu-1 TiCu-2 TiCu-3 TiCu-4 All Average(Ω) Unif. 4.71% 3.39% 4.35% 3.77% 4.99% X & Y X1 X2 Y1 Y2 All Average(Ω) Unif % 2.29% 3.15% 4.99% Max Min Unif. = Max + Min 19

20 600mm 600mm glass substrates Corning thickness Results: Ti Rsheet 6.37 Ω/ ±3.6% Cu Rsheet 117 mω/ ±4.7% n.b. Complete barrier/seed layer sputter deposition processes for fan-out RDL applications include several other steps that occur before PVD itself: a thorough degas, and some kind of pre-clean of the active surface immediately prior to metal deposition. We have PORs for both.

21 600 X 600mm glass, Ti/Cu 1000Å/2000Å, Sheet Resistance (mω) Y\X(mm) Average Rsheet (mω) Max Rsheet (mω) Min Rsheet (mω) Uniformity (%) % Uniformity = (Max Min) (Max + Min) 21

22 Panel Rsheet Avg.(Ω/ ) Uniformity (±%)

23 Term / Spec Target Utilization (TU) Collection Efficiency (CE) Sputter Efficiency (SE) Definition Percentage of target material sputtered by end of campaign lifetime (based on weight) Percentage of target material deposited on the wafer vs. material deposited on chamber walls and shields Material deposited on wafer as percentage of total target material available SE = TU * CE Goals for HVM: 65% or greater TU 50% or greater CE 30% or greater SE

24 In-House COO Model for linear transport of wafers or panels Equivalent to SEMI E Additional considerations included for COO modeling: Utilities (electrical power, water, etc.) Personnel (operators, engineers, maintenance technicians) (non-target) consumables and spares COO analysis here for barrier/seed film stacks of 1000Å Ti and 2000Å Cu on 300mm wafers

25 In-House COO Model for linear transport of wafers or panels Equivalent to SEMI E Additional considerations included for COO modeling: Utilities (electrical power, water, etc.) Personnel (operators, engineers, maintenance technicians) (non-target) consumables and spares COO analysis here for barrier/seed film stacks of 1000Å Ti and 2000Å Cu on 600mm x 600mm panels

26 We developed sputter deposition processes for barrier/seed layer applications in fan-out packaging on a carrier-based linear transport PVD system, the Intevac MATRIX, using a scanning magnet array magnetron configuration employing the LSMA. Metal film deposition uniformity, sheet resistance, and film adhesion results for Ti and Cu films on both 300mm round wafers and on 600mm x 600mm square glass panels are consistent with the process requirements of the advanced packaging industry. Our analysis of system throughput, PVD target utilization, and overall Cost of Ownership for the linear transport carrier-based PVD system, shows costs per wafer processed, or costs per panel processed, to be 40-50% lower than the traditional cluster systems routinely used in the packaging industry.

27 The processing cost advantages of linear transport systems have long been recognized by the silicon photovoltaic cell fabrication industry. PV industry learning might be usefully ported to other industries, for example semiconductor packaging, that run high volumes of material through sputter deposition tools.

28 Thank You! Terry Bluck, Chun-Chung Chen, Daniel Gallagher, Vladimir Kudriavstev, Lisa Mandrell, Billy Runstadler, Chris Smith Intevac, Inc. Santa Clara, CA, USA