# Presentation: 856206

## Visible Imager R&D 

**Visible Imager R&D **

**Natalie Roe**
**Lawrence Berkeley National Laboratory**
**November 11, 2003**

## Visible Sensor Science requirements
LBNL CCD 
Technical advantages
Technical issues
Fabrication R&D
Testing R&D
Packaging R&D
Other Visible Sensor Options
R&D Planning
Manpower
Schedule
Deliverables 
Milestones
Summary

- LBNL CCD
- Technical advantages
- Technical issues
- Fabrication R&D
- Testing R&D
- Packaging R&D
- Other Visible Sensor Options
- R&D Planning
- Manpower
- Schedule
- Deliverables
- Milestones
- Summary

- 150 mm LBNL-designed, DALSA-fabbed wafer. Large rectangular devices are 2k x 4k, 15 m; large square devices are 2.8k x 2.8k, 10.5 m with 4-corner readout.

## Visible Sensor Science Requirements

- z=0

- z=1.7

- Require good S/N in six filters over range 350 nm < < 1000 nm
- overlap with NIR is important
- The visible imager contributes to light curve studies and photometry for all SNe with z<1.7.
- The visible imager contributes to all other science, most importantly, gravitational weak lensing.
- benefits from smallest possible point spread function (PSF)
- Ideally, would use same visible sensor technology in imager and in spectrograph
- Must meet requirements of space operation
- radiation up to ~1 kRad
- heavily ionizing particles

**S/N>30**

**S/N>15-20**

**S/N>10**

**S/N>3**

## Visible Imager Preliminary Performance Specifications & Implementation 

|  coverage | 350 nm - 1000 nm |
| --- | --- |
| Read noise | 4 e-  |
| Dark current | 0.005 e-/pixel/sec |
| <QE> | 80% |
| PSF (rms) | 4 um |

**Performance goals**

| Field of view | ~ 0.34 square degrees |
| --- | --- |
| Plate scale | 0.1 arcsec / pixel |
| Detector type  | 3.5k x 3.5k LBNL CCD,10.5 m pixel |
| Filters | six special filters |

**Implementation**

**driven by gravitational**
** ****weak lensing survey**

## Scientific CCDs

**Scientific CCDs**

**Thinned,**
**back-illuminated**
**n-channel on p-type,**
**low-resistivity **
**silicon**

**Front-illuminated**
**n-channel on p-type, **
**low-resistivity**
**silicon**

**The “state-of the-art” for space-based visible imaging, eg Hubble ACS/WFC uses thinned     2k x 4k SITe CCDs**

## Hot Pixels in the Hubble WFC

- from Riess,
- 2002 HST Calibration Workshop

## WFC CTE Degradation

**WFC CTE Degradation**

- from Riess,
- 2002 HST Calibration Workshop

## Scientific CCDs

**Scientific CCDs**

**Thick, fully depleted,**
**back-illuminated p-channel**
**on n-type high resistivity**
**silicon**

**LBNL  CCD technology:**

**Thinned,**
**back-illuminated**
**n-channel on p-type,**
**low-resistivity **
**silicon**

**Front-illuminated**
**n-channel on p-type, **
**low-resistivity**
**silicon**

**The “state-of the-art” for space-based visible imaging, eg Hubble ACS/WFC uses thinned     2k x 4k SITe CCDs**

- 200 um

## LBNL CCDs

- LBNL Development started in early 1990’s:
- Fully depleted CCD’s fabricated on high-resistivity silicon developed for SSC HEP applications
- p-channel CCD has improved radiation tolerance
- Now being developed for astronomical applications, e.g. SNAP – higher QE over broader wavelength range than previous astronomical grade CCD’s, no fringing
- Patents Issued
***U.S. Patent 6,259,085 “Fully Depleted Back Illuminated CCD”,        Jul. 10, 2001.***
***U.S. Patent 6,025,585 “Low-resistivity photon-transparent window attached to photosensitive silicon detector”, Feb. 15, 2000.***

## LBNL CCDs in the Literature

- C.J. Bebek, J.H. Bercovitz, D.E. Groom, S.E. Holland, R.W. Kadel, A. Karcher, W.F. Kolbe, H.M. Oluseyi, N.P. Palaio, V. Prasad, B.T. Turko, and G. Wang "Fully depleted, back-illuminated p-channel CCD development," SPIE **5167** (2003) (paper at SPIE's "Focal plane arrays for space telescopes," San Diego, 4--6 Aug 2003)
- S.E. Holland, D.E. Groom, N.P. Palaio, R. J. Stover, and M. Wei, "Fully Depleted, Back-Illuminated Charge-Coupled Devices Fabricated on High-Resisitivity Silicon," IEEE Trans. Electron Dev. **50** (3), 225--238 (January 2003) LBNL-49992:
- Steve Holland, "An overview of CCD development at Lawrence Berkeley National Laboratory," (Version edited by Paola Amico & James W. Beletic will be published in the Proceedings of the Scientific Detectors Workshop (Waimea, HI, 16-21 June 2002).)
- C. J. Bebek, D. E. Groom, S. E. Holland, A. Karchar, W. F. Kolbe, M. E. Levi, N. P. Palaio, B. T. Turko, M. C. Uslenghi, M. T. Wagner, G. Wang "Proton radiation damage in high-resistivity n-type silicon CCDs," LBNL-49316, SPIE **4669**, 161-171 (2002).
- C. J. Bebek, D. E. Groom, S. E. Holland, A. Karchar, W. F. Kolbe, J. Lee, M. E. Levi, N. P. Palaio, B. T. Turko, M. C. Uslenghi, M. T. Wagner, G. Wang "Proton radiation damage in p-channel CCDs fabricated on high-resistivity silicon," LBNL-49316, IEEE Trans. Nucl. Sci., Vol. 49, pp. 1221--1225, (June 2002)
- D. E. Groom, P. H. Eberhard, S. E. Holland, M. E. Levi, N. P. Palaio, S. Perlmutter, R. J. Stover, and M. Wei, "Point-spread function in depleted and partially depleted CCDs," LBNL-45276, pp 205--216 in Proc. 4th ESO Workshop on Optical Detectors for Astronomy, Garching, Germany, 13-16 September 1999 (Kluwer, 2000).
- R. J. Stover, M. Wei, K. Ji, W. E. Brown, D. K. Gilmore, S. E. Holland, D. E. Groom, M. E. Levi, N. Palaio, S. Perlmutter "A 2kx2k High Resistivity CCD" To appear in Proc. 4th ESO Workshop on Optical Detectors for Astronomy, Garching, Germany, 13-16 September 1999.

## More LBNL CCD papers

- S. E. Holland, D. E. Groom, M. E. Levi, N. P. Palaio, S. Perlmutter, R. J. Stover, and M. Wei, "Large Format CCD Image Sensors Fabricated on High Resistivity Silicon," pp 179-182, Proc. 1999 IEEE Workshop on Charge-Coupled Devices and Advanced Image Sensors, June 10-12, Karuizawa, Nagano, Japan.
- D. E. Groom, S. E. Holland, M. E. Levi, N. P. Palaio, S. Perlmutter, R. J. Stover, and M. Wei, "Quantum Efficiency of a Back-illuminated CCD Imager: An Optical Approach," SPIE **3649**, 80-90 (1999).
- R. J. Stover, M. Wei, D. K. Gilmore, S. E. Holland, D. E. Groom, W. W. Moses, S. Perlmutter, G. Goldhaber, C.R. Pennypacker, N. W. Wang, and N. Palaio, ``A High Performance CCD on High Resistivity Silicon," SPIE **3505**, pp. 13-18, 1998 (Biejing, September 1998)
- S.E. Holland, G. Goldhaber, D. E. Groom, W. W. Moses, C. R. Pennypacker, S. Perlmutter, N. W. Wang, R. J. Stover, and M. Wei, ``Development of Back-Illuminated, Fully-Depleted CCD Image Sensors for use in Astronomy and Astrophysics," Proc. 1997 IEEE Workshop on Charge-Coupled-Devices and Advanced Image Sensors, Bruges, Belgium, June 5-7, 1997
- R.J. Stover, M. Wei, Y. Lee, D. K. Gilmore, S. E. Holland, D. E. Groom, W. W. Moses, S. Perlmutter, G. Goldhaber, C. R. Pennypacker, S. Perlmutter, and N. W. Wang, and N. Palaio, ``Characterization of a Fully Depleted CCD on High Resistivity Silicon," Proc. SPIE **3019**, 183 (1997)
- S. E. Holland, G. Goldhaber, D. E. Groom, W. W. Moses, C. R. Pennypacker, S. Perlmutter, N. W. Wang, R. J. Stover, and M. Wei, ``A 200 x 200 CCD Image Sensor Fabricated on High-Resistivity Silicon," IEDM Tech. Digest, 911 (1996) _[Postscript]_

***All papers are available online at http://www-ccd.lbl.gov***

## Astronomy with LBNL CCDs

-                 **“****The New Red Hot CCD”**
- September 2001 NOAO newsletter: Dumbbell Nebula
- taken at 3.5m WIYN with LBNL 2k x 2k CCD
- Blue: H- at 656 nm Green: SIII at 955 nm Red: 1.02 m

**Near-earth asteroids**
**Seyfert galaxy black holes**
**High redshift quasars**
**Planet hunting**
**LBNL Supernova cosmology**

**LBNL CCDs are installed at two**
**instruments at Kitt Peak:**
**- Multi-Aperture Red Spectrometer (MARS)**
**RC Spectrograph **
**(800 x 1980, 15 um pixel 300 um thick devices)**
**and at Lick on the **
**Hamilton Eschelle Spectrograph**
**(2k x 2k, 15 um pixel 200 um thick device)**
**Inquiries for 150 more LBNL CCDs received!**

**Science studies to date  **
**using LBNL CCD’s:**

## LBNL CCDs:  Technical Advantages

- Wavelength Coverage
- LBNL CCDs have extended quantum efficiency out to 1000 nm, where they  overlap with near-infrared HgCdTe devices

- Plot taken from “An Assessment of the Optical Detector Systems for the W.M. Keck Observatory,”
- by J. Beletic, R. Stover and K. Taylor  (January 2001)

## LBNL CCDs:  Technical Advantages

- Wavelength Coverage
- LBNL CCDs have extended quantum efficiency out to 1000 nm
- Radiation tolerance
-  traditional n-channel CCDs are sensitive to radiation damage in space due to CTE degradation, while  LBNL p-channel  CCDs are more radiation tolerant.

**10 ****6**** MeV/g**

## LBNL CCDs:  Technical Advantages

- Wavelength Coverage
- LBNL CCDs have extended quantum efficiency out to 1000 nm
- Radiation Tolerance
-  CCDs have been the detectors of choice for astronomy. But their charge transport mechanism has been very sensitive to radiation damage in space.
-  LBNL CCDs are more radiation tolerant than previous devices.
- Small Pixel / Reduced Diffusion
- LBNL CCD pixel scale is under our control - 10.5 m pixels in visible is a good match to the 18 um pixel sensors in the near-infrared (larger diffraction)
-  Diffusion in device should be smaller than pixel size
- Unique control of PSF in LBNL CCDs through bias voltage
- Have measured PSF as small as 6.4 m on 280 m thick device
- Scaling with thickness (1/d)  and HV (1/√HV) suggests 4 m is achievable for 200 m thick device operated at 100 V

## LBNL CCDs: Technical Issues

- Cosmic Rays
- Thicker device => increased number of pixels affected by a grazing incidence angle cosmic ray
- SNAP strategy is to take a series of 4 dithered exposures per image to reduce impact of cosmic rays
- Device availability
- LBNL CCDs used for scientific imaging to date have been manufactured in the LBNL Microsystems Lab
- Small R&D facility, not ideal for mass production
- Large scale production of LBNL CCDs requires an industrial partner
- Commercialization of the LBNL CCD fabrication process is a major SNAP goal and has been in progress for ~3 years with DALSA Semiconductor
**Challenge is to produce CCDs in quantity with ALL of the following properties:**
**large format**
**200 um thickness**
**high yield for scientific grade devices**

## LBNL CCD Performance

**Pixel size**
**Well depth**
**Quantum efficiency**
**Linearity**
**Dark current**
**Sensitivity****	**
**Persistence**
**Read noise**
**Charge transfer efficiency**
**CTE radiation degradation**
**Radiation**
**Protons: cold, powered**
**Heavy ion study**
**Diffusion**
**Intrapixel response**
**Packaging**
**Fabrication**

**10.5 ********m  devices work**
**130 ke for 10.5 ********m pixel.**
**Extended red performance realized.**
**Better than 1%.****	**
**2 e/hr/pixel.**
**3.5 ********V/e**
**Erase mechanism is effective.**
**2 e.**
**CTI ~ 10****-6**** pre-irradiation.**
**CTI degradation rate 1.5x10****-13**** g/MeV-cm****2**
**On-going study.**
**An activity during the next year.**
**6.4 um in 280 um device, on-going study**
**Extension of diffusion study**
**Underway**
**Partially commercialized.**

**R&D areas.**

## LBNL CCD Production Steps

**Front-side processing:****  **
**standard CMOS process, 8 masks**
**Back-side processing:**
**Thin wafers**
**Backside contact:  thin, in-situ doped polysilicon (ISDP)**
** ****requires high temperature (600 C) furnace**
**Anti-reflective coating**
**Complication:****  ****final front-side processing step is metallization, but Al melts at temperatures required for ISDP**
**must perform metallization after thinning and ISDP**
**requires additional handling of thinned wafers**
**or process changes (eg high-temp metal such as TiN)**

## LBNL CCD Process Flow

**Front-side process at commercial foundry**

- ISPD, contact etch & metallization at foundry

**Thinned (200 um), back-illuminated CCD**

- etch & metallization
- with TiN at foundry

**Thick, front-illuminated CCD**
- (QC, HV testing, irradiation)

- thin, ISDP, contact etch &
- metallization, AR coat
- at LBNL

- thin, ISDP and AR coating at LBNL

- thinning, ISDP,  etch, metallization &  AR coating at foundry

- “Hybrid Business Model”

- “Refractory metal”

- “Fully commercialized”

**All processing**
**at LBNL on 4” wafers**

- “LBNL MSL”

- “Front  illuminated”

## Status of CCD commercialization

**Initial work at DALSA Semiconductor on 4”, 525 um wafers:**
**Successfully transferred LBNL CCD technology to DALSA’s automated wafer handling production line**
**DALSA switched to fabrication on 6” wafers**
**Front-illuminated CCD’s produced (used in proton irradiation study)**
**Back-illuminated CCD’s produced, only AR coatings deposited  at LBNL **
**Wafer breakage problem limited progress (only 1 wafer survived)**
**Two more lots submitted to DALSA 6”  fabrication**
**Consistently high quality front-side illuminated devices**
**Back-illuminated devices produced with “hybrid business model”**
**good devices produced (smaller format)**
**some issues encountered in thinning to 200 um and in etching at LBNL**

## 70% Yield for DALSA front-side illuminated large format CCDs

*Based on cryogenic measurements of 10 packaged, *
*front-illuminated devices*

## New CCD Fabrication R&D

**New DALSA run is now in process with SNAP v. 1 CCD**
**10.5 ********m pixel, 3.5k x 3.5K with 4-corner readout**
**improvements to allow operation at higher voltages (improved diffusion)**
**4 variations in HV structures to protect against highly ionizing particles**
**Spectrograph CCD with frame store is also included**
**Some wafers fabricated with TiN instead of Al**
***first front-side processed wafers for hybrid business model delivered***
**CCD Fabrication R&D in next 2 years will study multiple paths:**
**Standard hybrid business model with DALSA**
**Refractory metal (promising initial results)**
**Qualify another commercial foundry to do all processing steps.**
**LBNL MSL produces all SNAP CCDs on 100 mm wafers**
**Goal is to produce large format, 200 um thick science grade devices  with good yield in a process that is mostly commercialized**

***See Steve Holland’s talk in the breakout session for more details***

## Layout for current DALSA run

- pixel spectrograph
- CCD

**Layout for current DALSA run**

- SNAP 35122

- 1k x 512 (4x)

- 800 x 1980
- NOAO MARS
- (2x, 1 12 m pixel
- with design for high
- voltage)

- 2210 x 802 9m
- 2-stage amps (4)
- ~ 20 fps (4x)

- 470 x 1264 24m
- Lick Guider (2x)
- (1 with 2-stage amp)

- SNAP 9 m
- Pixel spectrograph
- CCD 2226 x 868

- Template for
- 100 mm cutdown
- if necessary

## CCD Testing R&D

- Supports the CCD development effort by characterizing devices and feeding back information into later production cycles.
- Irradiation of devices to test radiation tolerance (protons and ******’s)**
- results presented at IEEE and SPIE
- Also used to qualify large-format devices for terrestrial astronomy
- recently tested an LBNL-packaged 2k x 4k device which is a candidate for Keck ESI
**Collaboration with R. Stover at UC Lick **
- cold probing of detectors prior to packaging
- validation of detector performance for Keck
- Joint effort with the SNAP electronics team to interface a CCD to the CRIC chip
-  ***more details in Henrik von der Lippe’s plenary talk***
- Outstanding issues
- Diffusion
- Intrapixel response
- Cross talk for multi-output devices
- QE spatial uniformity
- Radiation testing
- Protons while cold and powered
- 60Co while cold and powered (study MOS transistors & capacitors)
- Impact of heavy, highly ionizing particles (Yale von der Graf)

## Study of radiation tolerance in   p-channel CCDs

- p-channel CCD’s are more resistant to displacement damage from protons
- n-channel CCD’s develop phosphorus-vacancy defects after irradiation
- Dominant hole trap for p-channel is the divacancy
- Divacancy formation second order to impurity-vacancy formation
- Demonstrated improvement in commercially fabricated LBNL CCDs
- C. J. Bebek, D. E. Groom, S. E. Holland, A. Karchar, W. F. Kolbe, M. E. Levi, N. P. Palaio, B. T. Turko, M. C. Uslenghi, M. T. Wagner, G. Wang "Proton radiation damage in high-resistivity n-type silicon CCDs," LBNL-49316, SPIE **4669**, 161-171 (2002)
- C. J. Bebek, D. E. Groom, S. E. Holland, A. Karchar, W. F. Kolbe, J. Lee, M. E. Levi, N. P. Palaio, B. T. Turko, M. C. Uslenghi, M. T. Wagner, G. Wang "Proton radiation damage in p-channel CCDs fabricated on high-resistivity silicon," LBNL-49316, IEEE Trans. Nucl. Sci., Vol. 49, pp. 1221--1225, (June 2002) .
- see also:
- J.P. Spratt, B.C. Passenheim, R.E. Leadon, “The effects of nuclear radiation on P-channel CCD imagers,” in 1997 IEEE Radiations Effects Data Workshop, NSREC Snowmass 1997, Workshop Record.
- G.R. Hopkinson, “Proton damage effects on P-channel CCDs,” IEEE Trans. Nucl. Sci., **46**(6), pp. 1790-1796, December 1999

## Study of Diffusion in LBNL CCDs

- LBNL pinhole projector
- Beam spot size 1.3 m  rms
- Step size 0.4 m with 0.1 m resolution

## “Dial in” PSF with bias voltage

- x-y axis:  pixel number   z axis; arbitrary units
- 1100 x 800 back-illuminated CCD, 15 m pixels

## PSF Measurement

**6.4 um**

- “*Measurement of Lateral Charge Diffusion in Thick, Fully Depleted, Back-illulminated CCDs,”*
- by C.J. Bebek, A. Karcher, W.F.Kolbe,D.Maurath,V.Prasad,M.Uslenghi,M.Wager
- Presented by A. Karcher at 2003 IEEE meeting

- diff,m

- diff,m

***Note that 6.4 um in a 280 um thick device should ***
***scale to ~4 um in a 200 um thick device***

## CCD Packaging R&D

**Packaging effort is in support of CCD development effort**
**Have developed several types of packaging**
**simple window frame mount to support device characterization**
**4-side abuttable, wire-bonded mount for ground-based astronomy**
- Successful development effort; learned many useful lessons
- One LBNL-packaged device is a candidate for the KECK ESI
- Two more devices requested for KECK LRIS spectrograph upgrade (will be packaged by Richard Stover at UC Lick Observatory)
**3-side abuttable, bump-bonded mount for ground-based astronomy**
- In progress; build on success of previous method
- Improve by completely supporting CCD, eliminating wirebonds
- Qualify procedures, vendors for SNAP mount
**4-side abuttable, bump-bonded mount for SNAP**
- Goal:  mount large-format CCDs in  4-side abuttable package
- If possible, with co-located readout IC
- Yale is beginning to fabricate mechanical prototypes
- Want to be ready to package  first SNAP v. 1 CCDs from the current fabrication run

## 4-side abuttable, wirebonded packaging prototype

**CCD on bottom**

**AlN substrate**

**Circuit board and**
**connector**

**Moly foot with **
**mounting pins**

**Wirebonds**

## 3-side abuttable, bump-bonded packaging concept

- 1.4mm thick Silicon
- with single side  Aluminum traces

- Circuit substrate
- with Connector/flex

- CCD, 200m thick

-  Indium bump applied at wafer
-    level (TLMI, Austin Texas), then diced
-  CCD and substrate alligned and bump-bonded together by
- Mike Lesser, Univ. of Arizona Imaging Laboratory

- Gold bump
- (flattened wire bond bump)

- wirebond

- Underfill with Epotek
- 301-2 glue at 60oC

- Gold plated INVAR

- Stay Stick
- by
- Abelstick
- (thermo
- plastic
- glue)

## Flatness of first mechanical prototype part

- 200 um thick mechanical grade CCD bumpbonded to 1.4 mm thick silicon substrate

- Flat to within ~10 um (meets SNAP spec of +/- 10 um)

## 4-side abuttable, bump-bonded SNAP packaging concept

**4-side abuttable, bump-bonded SNAP packaging concept**

- CCD is bump-bonded to 1.4mm thick AlN substrate
- Vias in AlN bring signals through and traces route them to middle
- Circuit board glued to AlN substrate is wire-bonded to the signal traces
- An Invar36 block with a cutout is glued to the AlN substrate
- Beginning mechanical prototype, qualifying materials and vendors

***See Charlie Baltay’s talk in the breakout session***
*** ******for more details***

## Visible Sensors - Other options

- As a backup to the LBNL CCD we are also pursuing the possibility of using photo-diode arrays
- 2k x 2k engineering grade device ordered from Rockwell - arrived last week!
- 18 um Si PIN photodiodes hybridized to H2RG multiplexer
- Potential advantages
- same readout as HgCdTe
- no CTE loss
- can use as star-guider in window mode
- other projects are also interested in small pixel photodiodes
- Potential disadvantages
- big development effort: requires smaller pixel sensor and multiplexer, and hybridization at smaller pitch
- untried in astronomical applications (but strong interest)
- characteristics at cryogenic temperatures not yet verified
- photometric accuracy unknown
- Development path
- we have issued a study contract to Rockwell for small pixel development
- plan to measure dark current, read noise, diffusion of Rockwell 18 um pixel device at low temperature (expect that QE should be OK)

## Rockwell HyVisi Architecture

## 2k x 2k HyVisi Photodiode Array

**Sensor Side**

**Connector Side**

## HyVisi Data from Rockwell

**QE vs wavelength**

**Dark Current vs temp**

**SNAP operating temperature**

**.005 e/s/10 um pixel**

*More recent data show better dark current performance - want to test device ourselves** *

## Visible Sensor R&D Manpower

**CCD Fabrication:**
**Steve Holland, Nick Palaio, Gobin Wang (LBNL)**
**CCD Testing:**
**Gerry Abrams, Armin Karcher, Bill Kolbe, Julia Lundy, Hakeem Oluseyi, Val Prasad (LBNL)**
** ****Charles Baltay, Dave Rabinowitz (Yale)**
**CCD Packaging:**
**Charles Baltay, Will Emmet, Tom Hurteau,Andy Szymkowiak (Yale)**
**John Emes, Chris Hernikl, Bill Kolbe, Hakeem Oluseyi (LBNL)**
**Scientific Management**
**Chris Bebek, Natalie Roe (LBNL)**
***We have regular weekly CCD meetings via video with Yale, alternating between fabrication/testing and packaging***
***Progress reports are made on biweekly basis to Instrument meeting and to SNAP Management meeting***

## Visible Detector Roadmap

- Source
- Selection

-                                 FY04                                     FY05

- 1k x 1k
- 18m pixels

*2k x 2k*
*10 ****m pixels*

*Technology Study (Si:PIN)*

- Rockwell Science Center

*3.5k x 3.5k*
*10 ****m pixels*

*Primary Source (CCD)*

- DALSA Frontside    LBNL Finish

- 2.8k x 2.8k
- 10m pixels

- 3.5k x 3.5k
- 10m pixels

*3.5k x 3.5k*
*10 ****m pixels*

*Secondary Source (CCD)*
-     Industrial Vendor 4” Line

- Photodiode
- Qualification

*3.5k x 3.5k*
*10 ****m pixels*

*Secondary Source (CCD)*
-     LBNL 4” Line

- 2k x 4k
- 15m pixels

- 3.5k x 3.5k
- 10m pixels

*3.5k x 3.5k*
*10 ****m pixels*

- LBNL Technology

- Silicon Hybrid

## Visible Sensor R&D Schedule (1)

## Visible Sensor R&D Schedule (2)

## R&D Schedule Milestones

## R&D Summary

- Achievements in Past Year
- LBNL-packaged 2k x 4k device is candidate for Keck, two more CCDs to be packaged at UC Lick for Keck LRIS upgrade
- Added Yale to contribute to packaging & radiation testing
- Encouraging initial results on diffusion
- Business model progress on many fronts, including TiN as promising alternative
- New DALSA wafers with SNAP v. 1 CCD received
- HyVisi eng. grade device in hand for testing
- Key R&D Milestones:
- Establish fabrication process for LBNL CCD technology
- Goal is 200 um thick CCDs capable of holding 80-100 V bias
- Majority of production in commercial foundry
- 4-side abuttable package meeting all SNAP requirements
- Test CCD in SNAP environment (cold, powered radiation test)
-  Comparison of LBNL CCD with Si PIN diode technology
- CDR Preparation
- Science drive requirements for visible sensor
- Develop procurement and testing plan
- Provides the basis for budget and schedule
- Interface control documents (mechanical, electronic, optical)