Novel High voltage silicon-on-insulator Device with Composite dielectric buried Layer
A novel silicon-on-insulator (SOI) high voltage device with a composite dielectric buried layer (CD SOI) is proposed in this paper. In the proposed structure, the composite dielectric buried layer consists of Si 3 N 4 dielectric and low-k (relative permittivity) dielectric. The electric field strength in the buried layer is enhanced by the low-k dielectric. The Si 3 N 4 dielectric in the buried layer not only modulates the electric field distribution in the drift region, but also provides a heat conduction path for the SOI layer and alleviates the self-heating effect (SHE). The breakdown voltage (BV) = 362 V for CD SOI is obtained by simulation on a 1 μm SOI layer over 2 μm buried layer, which is enhanced by 26% compared with that of conventional SOI.
Partial SOI Power LDMOS With a Variable Low-$k$ Dielectric Buried Layer and a Buried P Layer
A power LDMOS on partial silicon on insulator (PSOI) with a variable low-k dielectric (VLKD) buried layer and a buried p (BP) layer is proposed (VLKD BPSOI). At a low k value, the electric field strength in the buried dielectric (Ej) is enhanced, and a Si window makes the substrate share the vertical voltage drop, leading to a high vertical breakdown voltage (BV). Moreover, three interface field peaks are introduced by the BP, the Si window, and the VLKD, which modulate the fields in the SOI layer, the VLKD layer, and the substrate; consequently, a high BV is obtained. Furthermore, the BP reduces the specific ON-resistance (Ron), and the Si window alleviates the self-heating effect (SHE). The BV for VLKD BPSOI is enhanced by 34.5%, and Ron is decreased by 26.6%, compared with those for the conventional PSOI, and VLKD BPSOI also maintains a low SHE.
Low dielectric constant CF/SiOF composite film deposition in a helicon plasma reactor
Abstract Low dielectric constant CF/SiOF composite films are deposited using tri-ethoxy-fluorosilane (FTES) and O 2 mixture in a helicon plasma reactor without intentional heating or biasing the substrate. Optical emission spectroscopy (OES) is used to study the relation between the relative densities of the radicals and the film properties. The OES data imply that the FTES and O 2 gases are greatly dissociated above the RF power of 900 W. Consequently, the deposition process of helicon plasma CVD where the source gases dissociated highly form CF/SiOF composite film is different from thermal CVD where the gases react chemically on the substrate and make the SiOF film. FTIR and XPS spectra show that the film has Si–F, Si–O, and C–F bonds. The Si–F and C–F bonds may lower the dielectric constant greatly. As the O 2 /FTES ratio decreases, the fluorine concentration increases and the dielectric constant decreases.