Randhir P. S. Thakur

Semiconductor Logic Technology Innovation to Achieve Sub-10 nm Manufacturing

Moores Law represents the cumulative effort by many participants to advance the productivity of electronic systems over the last 40+ years, resulting in enormous strides in the capability and ubiquity of electronics. This paper identifies the innovation challenges the semiconductor industry must overcome in order to propel the advance of semiconductor technology to the cadence of Moores Law. Key examples will highlight the solutions needed to enable advanced transistor and nano-scale interconnect fabrication. Solutions for tomorrows low voltage, low power process technologies will introduce new materials, unprecedented levels of interface control and new energy sources while at the same time addressing the increasing cost and complexity needed to sustain Moores Law well into the future.

How Rapid Isothermal Processing Can be a Dominant Semiconductor Processing Technology in the 21st Century

The growth and advancement of the electronic and photonic industry in the 21st century hinges on revolutionary new processing techniques that will overcome some of the most fundamental limitations of conventional methods. Rapid isothermal processing (RIP) based on incoherent radiation as the source of optical and thermal energy can play a major role in designing processing systems that offer the tight process control, low thermal budgets, low microscopic defects, high throughput and high yields required for almost every semiconductor device. Conventional RIP can be further optimized by fully exploiting the contribution of quantum photoeffects. The improved performance and reliability offered by RIP will make it the mainstream technology for the green manufacture of microelectronics, optoelectronics, solar cells, flat panel displays and microelectromechanical systems. Key issues related to the cost of ownership, design of RIP system based on the full utilization of photo-thermal effects and model based control systems are described. New experimental results for a number of processing steps are provided. These results demonstrate the importance of advanced RIP systems in providing better performance and lower defects for future devices.

A study of rapid photothermal annealing on the electrical properties and reliability of tantalum pentoxide

Rapid photothermal annealing is based on the use of vacuum ultraviolet (VUV) photons as the source of optical energy and tungsten halogen lamps as the source of optical and thermal energy. Tantalum pentoxide (Ta/sub 2/O/sub 5/) thin films deposited by thermal metalorganic chemical vapor deposition (MOCVD) have been annealed by RPP and conventional rapid thermal annealing (RTP). As compared to samples annealed by RTP, lower leakage current and lower trap densities were observed in the samples annealed by RPP.

Rapid Thermal Processing-Manufacturing Perspective

While repeatable and accurate measurement of temperature in rapid thermal processing (RTP) remains a subject of ongoing research, inception of large-diameter wafers and deep subhalf micron design rules may be viewed as good news for implementing RTP during the development phase for later transfer to volume manufacturing. To date, the only well-established application of RTP in manufacturing is silicide annealing. However, research during the past decade has demonstrated the feasibility of using RTP to replace essentially all furnace-based thermal processes in sub-half micron process flows. These developments in the RTP capability offer several technological and economic benefits such as improved defect control, higher product yields, and faster development cycles for DRAM-type technologies at a reduced cost and with an earlier entry of the driver products during the revenue-generating period. In this paper, we review several applications of RTP such as silicide anneals, borophosphosilicate glass (BPSG) reflow, dopant activation, and rapid thermal nitridation (RTN) and discuss the integration issues related to advanced process flows. Furthermore, we highlight important manufacturing parameters like throughput, machine cost and uptime, software and hardware issues, wafer dimensional analysis, and simulation expectations. While considering volume manufacturing, we make some calibration and process control recommendations.

High Performance High Dielectric Constant Films Deposited by Dual Spectral Source Rapid Isothermal Assisted Metalorganic Chemical Vapor Deposition (MOCVD)

Dual spectral source assisted MOCVD is an ideal technique for the deposition of high dielectric constant materials as well as other electronic and optical materials. Tungsten halogen lamps and a deuterium lamp are used as the sources of optical and thermal energy. Ta 2 O 5 films were deposited at 200°C for 30 minutes and annealed at 600°C for 30 minutes have shown leakage current densities as low as 10 −10 A/ cm 2 for gate voltage under 5V. To the best of our knowledge, these are the best results reported to date by other researchers. The high energy photons used in the in-situ cleaning and deposition process play an important role in obtaining high quality films of Ta 2 O 5 .

Advanced Dram Cell Dielectric Films using Rapid Thermal Processing

The reliable operation of a dynamic random access memory (DRAM) device requires a minimum level of charge to be stored in the capacitor. The nonlinear dependence between the scaling of the minimum charge and the cell area for higher DRAM densities is the driving force in the development of exotic capacitor structures and advanced cell dielectric materials. The conventional option of reducing the thickness of the silicon nitride dielectric films for high density DRAM applications will eventually be constrained by the increase in the leakage current due to direct carrier tunneling or by the decrease in the oxidation resistance of the films. In this paper we discuss the use of rapid thermal processing to modify the interface between the polysilicon storage node of the capacitor and the silicon nitride to improve the electrical and structural characteristics without any loss in capacitance. The influence of electrode roughness on the electrical behavior will also be discussed for the various dielectric stack combinations.