# Presentation: 936506

## Barrel Silicon Pixel detector

- Hiroaki Ohnishi
- [RIKEN]

## NEWS

- RIKEN-ALICE:SPD group held a meeting at CERN on 21/April In the meeting we confirmed following items.Based on the current schedule,
- 10-18 bump bonded PHENIX ladders will be delivered in September
- Another 40 bump bonded PHENIX ladders will be delivered by  end of JFY04 (end of March/2005), We will be able to have all ladders necessary to complete 1st layer of VTX by March/2005.
- All necessary components i.e. control chips etc, Analogue Pilot chip, digital pilot chips, GOL chips and optical components are available ( enough chips are already in ALICE hands or those are commercially available )

- In addition;
- 100 more bump bonded PHENIX ladders will be produced in ALICE framework and will delivered to us by February 2006.

## Inner 2 layer will be equipped with silicon Pixel detector

Single sector is made from 4 times 4-chip ladders. (~22 cm long)
Inner most layer will consist of 10 (12) sectors surroundingbeam pipe. 
Second layer will have  20 (24) sector surroundingbeam pipe. 

- Inner 2 layer will be equipped with silicon Pixel detector
- Single sector is made from 4 times 4-chip ladders. (~22 cm long)
- Inner most layer will consist of 10 (12) sectors surroundingbeam pipe.
- Second layer will have  20 (24) sector surroundingbeam pipe.

- Total number of ladders
- 	= 120 ladders (144 ladders)

## Pixel readout chip

- Pixel readout chip wafer
- 16 pixel readout chip wafers, each wafer will contain around 40 good chips on it, are already in our hand

- ~ 600 good chips

## Readout chip QA test

- Kohei and Johann are working on it
- Preparation for the massive QA test is finally done (final problem solved at May/25)
- At this moment, ~3 chips/hour~ one wafer (84 chips on it) per 1.0-1.5 week
- Our goal; two wafers by mid June for the preparation of PHENIX ladder bump bonding at VTTAnother 4 wafers by end of July➞ Completion of QA test of pixel r/o chip for 1st pixel layer
- 1st version of database for chip QA test is now available(used mysql + web interface)

## Snap shot during QA test

- Testing Pixel readout chip in clean room @ CERN byKohei Fujiwara and Johann Heuser

- Installation of the probe station for PHENIX into clean room at CERN is done in early March.

- It is finally operational in terms of  hardware + software from May-25

## Test system software

- Developed by ALICE-SPD group
- Based on LabView + ROOT for histograming
- Works for both chip QA test on wafer and test for bump bonded ladders

- Snap shot of the QA test

## Typical results from QA test

- Mean Minimum Threshold = 17.38 mV

- Average noise level = 1.8 mV

- chip# 43

- One dead pixel, another  8191 pixel are 100 % efficient with test pulse.

## Results so far

- 33 Class1 chips out of  63 chips in total
-  yield around 52 %     ALICE ; average 49 %

- Learning period;
- Tested between
- March 9 to May 25

- Class1 criterion
-   Dead pixel<1%
-   Min threshold <30mV
-   Idigital<270 mA, I analogue<350 mA
-   # of contact by probe station<3

## Pixel QA test database

- MySQL+Web based.

## 9 PHENIX ladders (4-chip ladder) will be on the 5 “ wafer 
Thickness of sensor is 200 m 
Passivation layer is made by SiO2 

6 wafers are ordered (producing 54 ladders in total) Additional 12 wafer will be ordered in August. 
Sensor wafer will be delivered to CERN during the week of 18/07/2004 

- 9 PHENIX ladders (4-chip ladder) will be on the 5 “ wafer
- Thickness of sensor is 200 m
- Passivation layer is made by SiO2
- 6 wafers are ordered (producing 54 ladders in total) Additional 12 wafer will be ordered in August.
- Sensor wafer will be delivered to CERN during the week of 18/07/2004

- PHENIX Pixel sensor wafer

- 1st PHEXNIX pixel ladder production (bump bonding) will be planed sometime in end of July to August and will be in our hand by September     	(2 sensor wafer will be processed ➞ 18 ladders Max.)

## Readout electronics before FEM

- Schematic view of Pixel readout system

- 2

- 1

- 2

- 1

- 2

- 1

- 2

- 1

- 128 bits

- North

- South

- Z=0

- 128 bits

- Control chip
- (a.k.a. PILOT chip)

- GOL

- FEM

- FEM

- Optical link with1.6 Gbps

- Need to test by us

- 64

- 32

- 32

- New ASIC chip designed
- Just submitted

## Design of new pilot chip

- Modification of exist ALICE pilot chip done by Hiroyuki. Now design completed.
- See detail in Hiroyuki’s presentation

- Design Submitted

## Goal for the Pixel BUS

- ALICE Pixel BUS structure

- 5 to 7 m Al

- 12 m Polyimide

- 5 m glue

- 15 m Al

- 5 m glue

- 12 m Polyimide

- 5 m glue

- 5 m glue

- 12 m Polyimide

- 5 m glue

- 12 m Polyimide

- 50 m Al

- 50 m Al

- Total radiation length = 0.173 % X0

- 5 to 7 m Al

- 5 m glue

- 12 m Polyimide

- 5 m glue

- Singal1

- Singal2

- Singal3

- Signal 1; (Vertical line)line connected withpixel chip with wire bonding

- Signal 2; (Horizontal line) connected with vertical line with through hole

- Signal 3; (for SMD)

## PHENIX Option 

- Option 1

- Option 2

- Option 3

- Easy (relatively)

- Aggressive

- Line spacing; 140 um pitch
- Material Budget;
- Cu;	Total ~ 0.376 %
- Al;	Total ~ 0.139 %

- Line spacing; 140 um pitch
- Material Budget;
- Cu;	Total ~ 0.306 %
- Al;	Total ~ 0.128 %

- Line spacing; 70 um pitch
- Material Budget;
- Cu;	Total ~ 0.236 %
- Al;	Total ~ 0.117 %

## Pixel BUS development

- So far we are concentrated to produce ALICE BUS structure to see the feasibility to make PHENIX BUS at JAPAN 	➞ PHENIX BUS will have finer pitch than ALICE BUS
- Fine pitch Al trace production by etching is now under control  (more less succeeded to produce ALICE BUS structure)
- Process of small diameter through hole is almost there
- Many progress are made during last one month
- It is very close to move R&D phase to producingPHENIX-Pixel BUS

- See more detail in Atsushi’s presentation

## Schedule

- 7/1

- 10/1

- 1/1

- 2004

- 2005

- 4/1

- 7/1

- 10/1

- 1/1

- 2006

- 4/1

- 7/1

- 1st Sensor wafer production

- Pixel R/O chip QA
- (6 wafers)

- Expected delivery day of
- 100 PHENIX ladders

- Pixel R/O chip QA
- (10 wafers)

- PIXEL bump bonding

- PIXEL bump bonding

- 2nd Sensor wafer production

- Pre-production
- of PIXEL BUS

- PILOT module prototyping

- Expected delivery day of 50 PHENIX ladders

- 1st integration of
- PIXEL BUS + PILOT Module
- +R/O chip or Ladders

- PIXEL BUS R&D

## Summary

- 16 IBM pixel readout chip wafers are in our hand. (~ 600 good chips )
- QA test of the chip is on going  (~ 1 wafer / 1.5 week)
- 6 pixel sensor wafers (9 ladders on it, so 54 ladders total) are ordered.Expected delivery date is mid-July
- 50 bump bonded PHENIX ladders will be delivered by end of March 2005
- Another 100 bump bonded ladders will be in our hand by Feb. 2006

- Design of Pixel control chip (new pilot chip) is submitted on 26/May.       It will back to CERN by mid-Sep.
- Enough amount of GOL and Analogue Pilot chips are in ALICE
- Optical components (package of pin diode + laser) are      commercially available

- Silicon Pixel Detector

- Readout electronics

- Pixel BUS

- We will be ready to move test production of PHENIX BUS by July
- 1st PHENIX test BUS production by end of this year

## Radiation does measurement during RUN4 

## Setup

- Four Silicon p-i-n diodes are installed around beam pipeon 2/18 and took way on 3/3. Delivered luminosity during those period was 285 b-1 Position of the sensor is as follows

- S

- N

- MVD frame

- 12”

- 1 3/8”

- 6 3⁄4”

- L4                 L5                 L6

- 5x5 mm2 inside Guard Ring

- L4

- L5

- L6

## Method to measure radiation dose

- Leakage current is measured @ full depletion voltage for each diode, before irradiation
- After irradiation, placed irradiated diode into oven and heated up 4 min. with 80 degree      ⇨ effectively, one month of annealing
-      Measurement is done by Marcus Wagner (Kyoto)
- In the paper NIMB186 (2002)100, It is explain how to extract radiation dose from measurement.
-  Dose = “leakage current” / “volume”/ “constant” 	constant;		Took from NIM paper; C = 4.56x10-17	leakage current; 	leakage current before-after irradiation  	volume;			in this measurement =  7.5 mm3

## Results

**Leakage current level before irradiation**

## Results

|  | L4 | L5 | L6 |
| --- | --- | --- | --- |
| Before irradiation | 60 pA | 60 pA | 73 pA |
| After irradiation* | 810 pA | 500 pA | 530 pA |
| I | 750 pA | 440 pA | 457 pA |

| Dose
(1 MeV neutron equivalent flux                           /cm2/ two weeks ) | 2.2x109 | 1.3x109
 | 1.3x109
 |
| --- | --- | --- | --- |

- Note;  NA60 pixel detector, 1.6 × 10**12** Indium ions on target / 4weeks,				~ 5      × 10**12** 1MeV n**eq** / cm**2** at inner most pixel
-            ALICE inner most Pixel expected dose in 10 years normal operation;
- 			 	~ 1.75 × 10**12** 1MeV n**eq** / cm**2**

- *) with 4 min. in 80 degree-C oven

## Backups

## BUS development at JAPAN  

-  Many progress in last a couple of month
-  Detail description will be presented in Atsushi’s presentation