SEN Ultra-High Energy Implanter (UHE) Developed for Next Generation Image Sensors

Abstract

The UHE is an ultra-high energy implanter developed by SEN Corporation. It was derived from the NV-GSD-HE3 by adding six RF resonators to the beam line. This extends performance so that singly charged boron ions can reach 2 MeV with beam current of 0.75 mA. The maximum energy for triple charged boron is 5 MeV with beam current of 1pA. For phosphorus ions, the UHE can accelerate doubly charged ions up to 4.4 MeV with beam current of 0.35 mA and quadruply charged ions up to 8 MeV with beam current of 1 pA. The primary application of the UHE is the image sensor market where it is used to increase the depth of CCD photodiodes into the surface of the wafer and thereby permit higher pixel density for image sensors. The second purpose is to improve productivity for relatively high boron doses at energies around 3 MeV. In order to address certain CCD defects, the system includes a state-of-the-art beam profile controller which allows optimization of implant damage and micro-uniformity. The ULE is currently used in production of high-end CCD's.

Fundamentals of Ion Implantation Technologies for Image Sensing Devices

“…Ultra-high energy implanters are demanded to form deeper layers of PD with higher sensitivity. The UHE's, radiation-free ultrahigh energy implanters with maximum energy of B and P/As are 5 MeV and over 8 MeV, respectively, has been developed based on the RF acceleration technology to meet such requirements (10). Boron implant at energy of 5 MeV, phosphorous implant at energy of 8 MeV and arsenic implant at energy of 8 MeV reach 6.2 µm, 4.3 µm and 3.8 µm in depth, respectively as shown in Fig.…”

Introduction of the S-UHE, a single-wafer ultra-high energy ion implanter

“…An ultra-high batch energy implanter was introduced in 2009 to address process requirements of leading edge image sensors (IS) [1,2,3]. As pixel size becomes smaller to increase image resolution and/or to reduce chip size, device sensitivity becomes lower.…”

“…One is the eighteen-stage RF linear accelerator from the previous UHE [1], a multi-wafer ultra-high energy implanter, offering maximum beam energy of 2 MeV per charge. The other is the field proven end station used by the MC3-II/GP [5], a singlewafer medium current implanter, which can provide a throughput of 450 wafers/hour or more.…”