High-density Chemical Vapor Deposition Research Articles

Deposition of Magnetic Carbon Nano Tubes with Chromium Seed

In this work, was obtained metallic decorated, single wall Carbon Nanotubes (SWCNTs) using High Density Chemical Vapor Deposition (HDPCVD) system on chromium thin films on a silicon wafers substrate. The characteristics of this deposition method are capacity of the segregation of metallic nanoparticlesas seed for the SWCNT growing. Use of magnetic particle decorated carbon nanotubes increases the applications in magnetic devices, magnetic memory, and magnetic oriented drug delivery. The CNTs’ spectra show a unique emission band, but due to the presence of the chromium, the spectra obtained in this work showed many bands that are related to the CNTs with different diameters. The CNTs obtained by the HDPCVD system are highly aligned and showed metallic features. Results of this work proved the possibility of obtaining the controlled deposition of aligned single-walled CNTs forest films decorated with chromium and suggested future studies in magnetic devices applications.

Impact of STI Gap-Fill Process Deposited by HDP-CVD in Flash Memory

This paper presents an evaluation of different oxides for shallow trench isolation (STI) gap-filling in flash memory devices. We have investigated that plasma induced degradation mechanism of high density chemical vapor deposition (HDP-CVD) oxide compared to non-plasma TEOS+O3 undoped silicate glass (USG) for STI gap-filling process. HDP-CVD has more hydrogen contents due to H+ penetration into underlying layer in plasma which generates more interface state density. Hydrogen depassivation model has been suggested to demonstrate the degradation mechanism of HDP-CVD device.

A Shallow and Deep Trench Isolation Process Module for RF BiCMOS

A shallow and deep trench isolation process module for high performance rf bipolar complementary metal-oxide-semiconductor (BiCMOS) is presented in detail. The shallow trench is etched prior to the deep trench, allowing the deep trench to be placed self-aligned to the shallow trench edge. By planarizing the polycrystalline silicon deep trench filling using chemical mechanical polishing (CMP) before etchback, the recess into deep trenches is decreased and polysilicon spacer formation at the active area edges is avoided. The poly CMP is stopped before all polysilicon in the active area is removed, to avoid polysilicon dishing and erosion of oxide on top of nitride on active area. Important issues arising during process development are discussed. Two different slurries were evaluated, which resulted in two different nonuniformities of polysilicon thickness. Nonuniformity transfers partially down to a range of recesses into the deep trenches, but the recesses were much smaller compared to the etchback only. High-density chemical vapor deposition was used for shallow trench filling and a direct shallow trench isolation-CMP process was developed. The feasibility of the process module was demonstrated using a 0.25 μm, 200 mm bipolar double-poly rf process with optional SiGe epi base. Electrical results from completed transistors are presented to verify the function of the module. © 2004 The Electrochemical Society. All rights reserved.