1 / 10

DSSD production

DSSD production. 20 March 2003 T. Tsuboyama (KEK). Production of L1 and L2 ladders. 72 DSSDs have been ordered by HPK. Minimum requirement : 2*6 + 3*12=48 50% spares However…. Charge collection efficiency. Laser-scan study by R.Abe n-side Efficiency is uniform.

tillie
Télécharger la présentation

DSSD production

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DSSD production 20 March 2003 T. Tsuboyama (KEK)

  2. Production of L1 and L2 ladders • 72 DSSDs have been ordered by HPK. • Minimum requirement : 2*6 + 3*12=48 • 50% spares • However…

  3. Charge collection efficiency • Laser-scan study by R.Abe • n-side • Efficiency is uniform. • p-side floating strips. • L1-3: shows large charge deficit, worse than the estimation by capacitance network. • L4: shows charge loss, however, the loss is smaller than L1-3 DSSDs. The loss is consistent with calculation.

  4. How to improve the efficiency? • Since readout strips are healthy, the bulk and implantations may be healthy. • The metal on the floating strips is doubtful. • Tsuboyama and Hazumi visited HPK and discussed with the designer (Yamamura).

  5. Yamamura’s suggestions • Wire-bonding pads on un-depleted area is suspicious. • Large capacitance between the pad and silicon bulk. • In L4 sensors, pads are made in the depletion region. • The extra capacitance could absorb the charge induced by particles. Position of the guard ring

  6. How to recover efficiency? • Move bonding pads to the depletion region. • It is geometrically impossible in the L1-3 sensor. • Pads are in the depletion region in L4 sensor. • Remove aluminum traces from floating strips. • The metal on the floating strips is not useful. • Increase coupling capacitance between floating and readout strips. • Extending metal strips and overlaping the adjacent implantations. (Hazumi) (5)

  7. 50 50 50 50 20000 20000 20000 Example of overhang (Hazumi) Aluminum Overhang 56 Wao = 112 p+ strip 6 25 20000 20000 20000 70000 20000 1750 20000 20000 28 75 3 Unit=m

  8. R&D sensors • Short strip length sensor • P-strips in L1-3 DSSD is short (25.6mm) • The sensor becomes short accordingly. • Long strip-length sensor • The sensor will not be used in SVD2.1. • Strip length is 70 mm. • R&D for future large area sensors.

  9. Test set up • VA1TA hybrids is adopted for the test. • Test sensors are in production. • Partially functional hybrids are in KEK. • Sensors are starting the production. • Detector frames are now in KEK. • Assembly work will be done in KEK(?) Electrodes for bias Hybrid (dummy) Frame (glass epoxy) A large hole for the laser scan

  10. Plan • The R&D sensor • Delivery: End of March • Assembly and evaluation takes 1-2 weeks. • The SVD2.1 sensors • No change in the bulk and implantation. • Production starts after the test sensor is shipped. • Design of the top aluminum traces can be determined later, in May. • Delivery in September.

More Related