디지털 X-ray용 센서 기술 및 동향

1 July/August 2007 24 (1995) , . (2006) , . (1998) , . 1. X-ray . 2. X-ray . X-ray .. 19 , X-ray . pm ~ nm X-ray , . X-ray X-ray 1 . X-ray 100% , . X-ray (digital semiconductor detector).

2 X-ray ROIC(Readout Integrated Circuit, ) computer .X-ray (Medical) .X-ray X-ray X-ray (target) . X-ray . X-ray Cr, Fe, Co, Ni, W high-Z material( ) .. X-ray . X-ray X-ray X-ray . X-ray , X-ray . X-ray X-ray . X-ray X-ray 3 . X-ray X-ray.

3 July/August 200725 3. X-ray. 4. X-ray . 5..X-ray . X-ray , , , , . X-ray .. (1) (Contrast)X-ray (contrast) . C . I , I .(2) Signal-to-noise ratio (SNR) , .. Photonic , . fixed pattern read-out electronics . Fixed pattern , . read-out electronic . Photonic quantum SNR.

4 N . (3) Detective quantum efficiency (DQE)DQE , . X-ray , , , X-ray . DQE July/August 2007 26 8. PIN . 9. Energy Band ) Bettina Mikulec, Single Photon Detection with Semiconductor Pixel Arrays for Medical Imaging Applications, CERN, Geneva, Switzerland, June ) DR( Radiography), 13) Lawrence Pinsky, MEDIPIX: A Technology Developed at CERN, That Can Be Developed As An Active Real Real-time Space Radiation Dosimeter, University of Houston 6.. 7. Bump .1) X-ray ( ) X-ray X-ray - (Direct) X-ray (Scintillator) (Indirect).

5 42) X-ray 5 . X-ray 63) ROIC .. , X-ray , X-ray (CdTe, CZT ) , CMOS readout . electronics bonding( 7)2) , . PhysicsX-ray (source) . X-ray , X-ray . PN , PIN , Schottky , Avalanche . 9 Photon (valance band) (band gap) (conduc-tion band) . ( ).

6 ( 10) - N (Quasi-Neural n-region) , P July/August 200727 10. X-ray - . 11.. 12.. 13.. (Quasi-Neural p-region) . P N N P .( 11) P , N .. PN . X-ray (source) , (charge collection efficiency) . (dark current- -) . PIN . n- n- n.

7 PIN X-ray . (ROIC, Readout Integrated Circuit) - . X-ray , - A/D (charge integration mode) . X-ray - ROIC read-out . X-ray photon X-ray photon - , (read-out) SNR . (single photon counting mode) . , 1980 , tracking microstrip semi-conductor drift.

8 PCC(photon counting chip) pixel Hybrid pixel . 12 read-out bump- July/August 2007 28 16. EDA ROIC single pixel . 17. ROIC . 18.. 14.. 15..bonding , X-ray - . read-out (Preamplifier) ( 13). 1 0 ( 14), 1 ( 15). 12~15 readout . X-ray (charge integration mode) SNR(signal to noise ratio) . X-ray , SNR.

9 EDA(Electronic design automation) , , , CMOS(Complementary Metal-Oxide-Semiconductor) . X-ray , PCB, , , 2 3 . , X-ray , (Mammography), CT(Computed Tomography) , .. SoC(System on Chip).