1. MPC-Ex Project in Korea
Y. Kwon
Yonsei University
on behalf of Korean MPC-EX group

2. J.S. Chai5, K.I. Hahn2, S.Y. Han2, H.S. Hong4, K.S. Joo4,
D.S. Kim4, E.J. Kim1, Y.K. Kim3, Y. Kwon6, J.H. Lee 1, K.S. Lim4,
H.J. Moon4, H.M. Park4, J.M. Park 1, S.Y. Park, D.G. Sue6
Chonbuk National University. 1 ETRI. 2Ewha Womans University.
3Hanyang University, RISP. 4Myongji University.
5Sungkyunkwan University. 6Yonsei University.

3. PHENIX MPC-Ex detector
(Muon Piston Calorimeter, An EMCal)
MPC-Ex
(MPC Extension)
0 & 
3 < |y| < 4
separation
up to
E>100 GeV

4. Si-W sandwich preshower detector
~1X0
MPC-Ex
MPC
-RM<y<RM
(EM Shower by single e) y z

5. General(Operation) -

6. Fabrication process Metal layer deposition Passivation
Etch for contact
Ion implant
High purity Si wafer
Oxidation
Oxide layer deposition

7. Possibility in Korea R&D environment 6 inch fabrication line
1 cm2 ~ $ 2
6 inch fabrication line
8 inch fabrication line

8. Actual process sheet

9. Fabricated minipad sensor

10. Dicing sensor
This shows the sensor dicing. After sawing the wafer, it attached to the kind of sticker. So we need to pickoff process.
And after the pick off process, we get the minipad sensor.

11. Issues

12. Novel guard ring system design and implementation
2013 IEEE NSS/MIC/RTSD, COEX, Seoul, Korea, October 27-November 2, 2013
Novel guard ring system design and implementation
for punch-through protection toward the detector
dicing edge with improved radiation tolerance and
reduced dead area
*This research was supported by the U.S. Department of Energy: Contract No. DE-AC02 -98CH10886
Zheng Li, Wei Chen, Edward Kistenev, and Andrei Sukhanov
Brookhaven National Laboratory, Bldg. 535B, Upton, NY , USA
Youngil Kwon, Dong gon Sue
Department of Physics, Yonsei Univ., 50 Yonsei-ro, Seoul, , Korea
Kunsik Park, Jongmoon Park
Electronics and Telecommunications Research Institute, 218 Gajeong-ro, Daejeon, , Korea
John Lajoie
Iowa State University, 2229 Lincoln Way Ames, IA 50011, USA

13. Old GRS --- Struture
It is a typical multi-guard ring system to ensure high voltage operations, see refs [1-6]

14. Old GRS --- Simulations
V=250 V and oxide charge density of 1x107/cm2
High leakage current may be due to the punch-through effect to the dicing edge p+ implants area that is highly damaged with a finite electric field for current injection

15. 2 Concept of Novel GRS Lower E-fields Segmented, low-dose n+-implant
A segmented, low-dose (a few times of 1012/cm2) n+-implant on near GRS can remove the detector oxide-property dependence with lower E-field

16. 3 Simulations Depletion edge far away from dicing edge
Electron concentration profile
One can dice
it here –
Reduction in
dead space
of 500 m!
Since the
implanted
charge is much
higher than
that induced
by oxide
irradiated to
10 Mrad, it is
rad-tolerant
to 10 Mrad
V=200 V and oxide charge density of 2x1011 to 2x1012 /cm2

17. Improvements (Details by K.S. Lim)
30 
1.5 cm
3 cm 1 2 3 4
6 cm

18. Submission for main production
Main production started and new submission will be made in every 3 weeks.
1st submission(executed), the last week of Sep.
2nd submission(executed), the 3rd week of Oct.
3rd submission(planned), the 2nd week of Nov.

19. Sensor Certification log (Details by S. Y. Hahn)
CV test
Before dicing
Short test
Guard ring & pattern leakage current test
After dicing
Stability : x3 of full depletion voltage (90V) & 2 hours
So from these result we could make the outline of sensor certification logging system.
The first feature that we need to make data is capacitance verses voltage.
And Before the dicing process, we need to do the short test and leakage current test of guard ring and pattern for certificate each steps of fabrication are done properly.
And after the dicing process, we need to do the guard ring and pattern leakage current test for check the overall sensor performances and also stability test applied 3 times of full depletion voltage and in two hours.

20. Summary Korea has a good potential in silicon sensor.
A sequence of R&D for the silicon minipad sensor has been performed.
Main production has started.
Sensor log has been defined.