1724 IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 51, NO. 4, AUGUST 2004 A New Oxide-Trap Based on Charge-Pumping (OTCP) Extraction Method for Irradiated MOSFET Devices: Part I (High Frequencies) Boualem Djezzar, Slimane Oussalah, and Abderrazak Smatti Abstract—In this paper, we propose a new extraction method of radiation-induced oxide-trap density , called Oxide-Trap based on Charge-Pumping (OTCP). This part presents the HF-OTCP method, which relies on high-frequency (HF) standard charge-pumping measurement. By applying an HF gate voltage signal, we avoid the border-trap effect in CP current measurements. Hence, will be only due to the interface-trap contribution. We establish, using the HF-OTCP method, that is only dependent on (threshold voltage shift) and (increase of maximum CP current), where is caused by radiation-in- duced interface-trap increase . We also clearly show that and can be obtained from lateral and vertical shifts of Elliot’s charge-pumping curves, respectively. Thus, this new pro- cedure allows the determination of without needing any ad- ditional techniques. Finally, this procedure can be used in rapid hardness assurance test to evaluate both radiation-induced oxide and interface traps. Index Terms—Charge-pumping, MOSFETs, Oxide-Trap based on Charge-Pumping (OTCP), radiation effects, traps. I. INTRODUCTION D EVELOPMENT of a reliable test procedure to predict ra- diation response of integrated circuits (ICs) in space from a standard test laboratory is very important. To attain this pur- pose, intensive research efforts and technological innovations have been made. This development consists of two parts: 1) im- provement of procedure test steps and 2) development of simple and rapid electrical characterization techniques easily adapted to production line. Over the last several years, considerable work has been fo- cused on assurance test procedures and guidelines [1]–[8]. This effort has given two test methods. The first one is described in MIL-STD.883 (Military Standard), TM1019.4 (test method) [9]. This method governs the testing of packaged semiconductor microcircuits in the Department of Defense (DoD). TM1019.4 was improved to TM1019.5 [10]. Recently, TM1019.5 was changed to TM1019.6 [11]. The second one is European Space Agency/Space Components Coordination (ESA/SCC), Basic Specification (BS) 22 900 [12]. BS 22900 focuses on im- proved simulation of low-dose-rate space environments, while MIL-STD.883 focuses on conservative estimation of MOS Manuscript received October 28, 2003; revised March 12, 2004. This work was supported by the Fond National de la Recherche. The authors are with the Microelectronics Division, Centre de Développe- ment des Technologies Avancées, Algiers 16303, Algeria (e-mail: boualem.djezzar@cdta.dz; bobdjezzar@hotmail.com). Digital Object Identifier 10.1109/TNS.2004.832549 hardness for space and strategic applications. More details on comparison between the two test methods are given in [8]. On the other side, intensive research has been carried out on the electrical characterization techniques of MOSFET gate oxide and Si–SiO interface degradation caused by radiation [13]–[17]. Therefore, several techniques are routinely used to electrically sense different radiation-induced traps in oxide and at or near interface of MOS devices. The practical ones are C-V [13], subthreshold slope [14], Mid-gap [15], Dual-Transistor Charge-Pumping (DTCP) [16], and standard charge-pumping [17] methods. They were improved to separate the contribution of different traps to radiation-induced threshold voltage shifts in MOSFETs. The mid-gap and the subthreshold methods are well suited for relative variation of the interface state density deter- mination. However, the CP technique is a useful tool to probe a weak interface-state density in MOS transistors. It is also effec- tive for a small geometry transistor characterization. In fact, once the origin of the CP current was understood, it was adopted as a technique for measuring the interface-trap den- sity in MOS transistors under various applications. It has been used in reliability of MOSFETs such as in Fowler–Nordheim (FN) stress [18], radiation damage [19]–[21], and hot carrier degradation [22]. Moreover, it has been successfully adapted to power transistors [23] and SOI devices [24]. Furthermore, it has been improved in order to extract other parameters, such as border traps [25]–[29], both lateral [30] and vertical [31] spatial distribution of traps, and their energetic distribution [32]. Sacks [33] has shown that the three-level CP method not only allows one to determine the trap energy distribution, but also the en- ergy distribution of the traps for both electron and hole capture as well as emission processes. The aim of this paper is to introduce a new electrical method, called High-Frequency Oxide-Trap based on Charge-Pumping (HF-OTCP), to extract the radiation-induced oxide-trap. We show for the first time that the CP technique is able to sepa- rate and measure the contribution of both radiation-induced interface and oxide traps to threshold voltage shift at high fre- quencies, without the need for additional electrical techniques. This makes it a powerful tool for rapid and routinely electrical characterization in a hardness assurance test of MOSFETs device qualification for space and strategic applications. The HF-OTCP method is validated on irradiated NMOS transistors using rays. The results obtained through the HF-OTCP are qualitatively in perfect correlation with those given by different authors using other techniques [34]–[37]. For example, the following major aspects of total dose radiation effects are 0018-9499/04$20.00 © 2004 IEEE