Non-contact C-V and photoluminscence measurements for More-than-Moore SOI devices J.P. Gambino, D. Price, R. Jerome, H. Ziad*, T. Frank** ON Semiconductor Gresham,OR, * Oudenaarde, Belgium, ** Rochester, NY jeff.gambino@onsemi.com A. Kerekes*, V. Samu*, A. Ross, Z. Kiss*, J. Byrnes Semilab Tampa, FL *Budapest, Hungary . Abstract – A number of More-than-Moore (MtM) devices use Silicon-on-Insulator (SOI) wafers, including power devices and CMOS image sensors. Non-contact capacitance-voltage (CV) and photoluminescence measurements are well established for characterization of dielectrics and minority carrier lifetime on bulk Si wafers. In this study, we extend these measurements to More-Than-Moore (MtM) Silicon-On-Insulator (SOI) device wafers. Keywords— Non-contact C-V, SOI, Photoluminescence I. INTRODUCTION Silicon-on-Insulator technology was originally developed for radiation hardness and Moore’s law high performance logic devices [1], and recently has been extended to a number of More-than-Moore devices, including RF switches [2], power devices [3], and backside illumination (BSI) CMOS image sensors (Fig. 1)[4-6]. Figure 1: Schematic of (a) high voltage device on SOI and (b) BSI image sensor. Note that the device Si layer in the BSI image senor is essentially an SOI structure. Non-contact capacitance-voltage (CV) measurements using corona charging are well established techniques for measuring dielectric layers on bulk Si [7], and has recently been demonstrated for BSI image sensors [6]. The contact potential difference at the surface is measured with a vibrating electrode that is ~ 250 μm above the dielectric layer (Fig. 2). The change in the contact potential difference, ΔVcpd, equals the change in voltage drop across the dielectric, ΔVOX, plus the change in voltage drop across the semiconductor depletion layer, ΔVSB. With illumination, the depletion layer collapses (VSB ~ 0), and the measured Vcpd is due to VOX only. ΔVSB can then be measured by comparing the change in Vcpd with corona charge in light versus dark conditions. This method can be used to measure the electrical dielectric thickness, TOX, flat band voltage, VFB, the total charge required to achieve the flat band condition, QTOT, and the interface trap density, DIT, across the silicon bandgap in an energy range from flat band to deep inversion (Fig 2). Figure 2. Schematic of non-contact capacitance measurement using corona charging to place a charge on the surface of the dielectric. Figure 3. Schematic of energy bands for thin SiO2 layer on p-type Si; (a) Initial condition in depletion showing charge in and on the oxide; (b) After corona charging to the flat band condition. Another non-contact characterization method is photoluminescence imaging [8-10]. Micro photoluminescence imaging (μPL Imaging) produces excitation of charge carriers in the semiconductor using high intensity illumination. These charge carriers recombine through various recombination 978-1-7281-8645-0/21/$31.00 ©2021 IEEE ASMC 2021