Fabrication of phosphor micro-grids using proton beam lithography

TY - JOUR

T1 - Fabrication of phosphor micro-grids using proton beam lithography

AU - Auzelyte, Vaida

AU - Elfman, Mikael

AU - Kristiansson, Per

AU - Pallon, Jan

AU - Wegdén, Marie

AU - Nilsson, Christer

AU - Malmqvist, Klas

AU - Doyle, BL

AU - Rossi, P

AU - Hearne, SJ

AU - Provencio, PP

AU - Antolak, AJ

N1 - The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Nuclear Physics (Faculty of Technology) (011013007)

PY - 2006

Y1 - 2006

N2 - A new nuclear microscopy technique called ion photon emission microscopy or IPEM was recently invented. IPEM allows analysis involving single ions, such as ion beam induced charge (IBIC) or single event upset (SEU) imaging using a slightly modified optical microscope. The spatial resolution of IPEM is currently limited to more than 10 mu m by the scattering and reflection of ion-induced photons, i.e. light blooming or spreading, in the ionoluminescent phosphor layer. We are developing a '' Microscopic Gridded Phosphor '' (also called Black Matrix) where the phosphor nanocrystals are confined within the gaps of a micrometer scale opaque grid, which limits the amount of detrimental light blooming. MeV-energy proton beam lithography is ideally suited to lithographically form masks for the grid because of high aspect ratio, pattern density and sub-micron resolution of this technique. In brief, the fabrication of the grids was made in the following manner: (1) a MeV proton beam focused to 1.5-2 mu m directly fabricated a matrix of pillars in a 15 mu m thick SU-8 lithographic resist; (2) 7:1 aspect ratio pillars were then formed by developing the proton exposed area; (3) Ni (Au) was electrochemically deposited onto Cu-coated Si from a sulfamate bath (or buffered CN bath); (4) the SU-8 pillars were removed by chemical etching; finally (5) the metal micro-grid was freed from its substrate by etching the underlying Cu layer. Our proposed metal micro-grids promise an order-of-magnitude improvement in the resolution of IPEM.

AB - A new nuclear microscopy technique called ion photon emission microscopy or IPEM was recently invented. IPEM allows analysis involving single ions, such as ion beam induced charge (IBIC) or single event upset (SEU) imaging using a slightly modified optical microscope. The spatial resolution of IPEM is currently limited to more than 10 mu m by the scattering and reflection of ion-induced photons, i.e. light blooming or spreading, in the ionoluminescent phosphor layer. We are developing a '' Microscopic Gridded Phosphor '' (also called Black Matrix) where the phosphor nanocrystals are confined within the gaps of a micrometer scale opaque grid, which limits the amount of detrimental light blooming. MeV-energy proton beam lithography is ideally suited to lithographically form masks for the grid because of high aspect ratio, pattern density and sub-micron resolution of this technique. In brief, the fabrication of the grids was made in the following manner: (1) a MeV proton beam focused to 1.5-2 mu m directly fabricated a matrix of pillars in a 15 mu m thick SU-8 lithographic resist; (2) 7:1 aspect ratio pillars were then formed by developing the proton exposed area; (3) Ni (Au) was electrochemically deposited onto Cu-coated Si from a sulfamate bath (or buffered CN bath); (4) the SU-8 pillars were removed by chemical etching; finally (5) the metal micro-grid was freed from its substrate by etching the underlying Cu layer. Our proposed metal micro-grids promise an order-of-magnitude improvement in the resolution of IPEM.

KW - proton beam lithography

KW - microfabrication

KW - lithography

KW - ionoluminescence

KW - phosphor

U2 - 10.1016/j.nimb.2005.08.031

DO - 10.1016/j.nimb.2005.08.031

M3 - Article

VL - 242

SP - 253

EP - 256

JO - Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms

JF - Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms

SN - 0168-583X

IS - 1-2

ER -