In situ Investigation of Individual Filament Growth in Conducting Bridge Memristor by Contact Scanning Capacitance Microscopy

We report on the application of Contact Scanning Capacitance Microscopy (CSCM) to trace the growth of an individual Ni filament in a ZrO2(Y) film on a Ni sublayer (together with a conductive Atomic Force Microscope probe composing a nanometer-sized virtual memristor). An increasing of the filament length in the course of electro-forming results in an increasing of the capacitance between the probe and the sample, which can be detected by CSCM technique. This way, the filament growth can be monitored in real time in situ.

Resistive Open Defect Isolation in Nano-Probing

In this paper, we present case studies of localizing resistive open defects using various FA techniques, including two-terminal IV, two-terminal Electron-Beam Absorbed Current (EBAC), Electron Beam Induced Resistance Change (EBIRCh), Pulsed IV, Capacitance-Voltage (CV) and Scanning Capacitance Microscopy (SCM). The advantage and limitation of each technique will also be discussed.

High-Resolution Two-Dimensional Imaging of the 4H-SiC MOSFET Channel by Scanning Capacitance Microscopy

In this paper, a two-dimensional (2D) planar scanning capacitance microscopy (SCM) method is used to visualize with a high spatial resolution the channel region of large-area 4H-SiC power MOSFETs and estimate the homogeneity of the channel length over the whole device perimeter. The method enabled visualizing the fluctuations of the channel geometry occurring under different processing conditions. Moreover, the impact of the ion implantation parameters on the channel could be elucidated.

A Novel Sample Preparation Approach for Dopant Profiling of 14 nm FinFET Devices with Scanning Capacitance Microscopy

Three-dimensional device (FinFET) doping requirements are challenging due to fin sidewall doping, crystallinity control, junction profile control, and leakage control in the fin. In addition, physical failure analyses of FinFETs can frequently reach a “dead end” with a No Defect Found (NDF) result when channel doping issues are the suspected culprit (e.g., high Vt, low Vt, low gain, sub-threshold leakage, etc.). In new technology development, the lack of empirical dopant profile data to support device and process models and engineering has had, and continues to have, a profound negative impact on these emerging technologies. Therefore, there exists a critical need for dopant profiling in the industry to support the latest technologies that use FinFETs as their fundamental building block [1]. Here, we discuss a novel sample preparation method for cross-sectional dopant profiling of FinFET devices. Our results show that the combination of low voltage (<500eV), shallow angle (~10 degree) ion milling, dry etching, and mechanical polishing provides an adequately smooth surface (Rq<5Å) and minimizes surface amorphization, thereby allowing a strong Scanning Capacitance Microscopy (SCM) signal representative of local active dopant (carrier) concentration. The strength of the dopant signal was found to be dependent upon mill rate, electrical contact quality, amorphous layer presence and SCM probe quality. This paper focuses on a procedure to overcome critical issues during sample preparation for dopant profiling in FinFETs.

Scanning Capacitance Microscopy and Spectroscopy for Root Cause Analysis on Location Specific Individual FinFET Devices

In 1986 the Atomic Force Microscope (AFM) was invented by Gerd Binnig, Christoph Gerber, and Calvin Quate [1]. Since then, numerous analytical techniques have been developed and implemented on the AFM platform, evolving into what is collectively called the Scanning Probe Microscope (SPM). The SPM has since become well established as a mainstream analytical instrument with a continually increasing role in the development of nanoscale semiconductor technologies providing critical data from initial concept to technology development to manufacturing to failure analysis [2]. Scanning Capacitance Microscopy (SCM) has a longstanding, well-established track record for detecting dopant-related mechanisms that adversely affect device performance on planar (Field Effect Transistor) FETs as well as other structures (e.g., diodes, capacitors, resistors). The semiconductor industry’s transition to three dimensional FinFET devices has resulted in many challenges with regard to device analysis. This is especially true when it is necessary to perform detailed dopant analysis on a specific device; the device may be comprised of a single or multiple fins that have been called out specifically through traditional fault localization techniques. Scanning Capacitance Spectroscopy (SCS) is an analytical method, implemented on the SCM platform in which a series of DC bias conditions is applied to the sample and the carrier response is recorded using SCM [3]. SCS has a proven history of highlighting dopant related anomalies in semiconductor devices, which, in some instances, might not otherwise be “visible”. This paper describes successful application of SCM and SCS in showing, in full detail, a dopant-related failure mechanism on an individual, location-specific 14 nm FinFET.