In this paper, we describe a robust process for depositing diamond-like carbon (DLC) films from an r.f. inductively coupled CH4-plasma source (18 cm in diameter). This process represents a significant improvement in ability to carry out reliable fault-free and long duration operation. A pure Maxwellian distribution of discharge electrons (homogeneity) and a wide range of electron temperatures are important attributes of the r.f. plasma source. By variation of r.f. power the composition and plasma density were optimized to minimize the source contamination and provide enhanced deposition stability and reproducibility. Beam energy was varied in the range 100–900 eV to obtain different combinations of sp3sp2 ratio and level of hydrogenation. Hard coatings with high electrical resistivity and moderate stress were deposited on the silicon, silicon dioxide, glass, and Al2O3TiC substrates. Deposition rate and coatings thickness ranges were 10–40 nm/min and 5–1000 nm, respectively. The deposition uniformity was within 3% over 16.5 cm.

Diamond-like carbon (DLC) films with 4-400 nm thickness were deposited on silicon substrates using direct ion beam from an RF inductively coupled CH4 - plasma (ICP) source. The dependence of the film electrical and photoelectrical properties on methane flow were examined. Two kinds of trapping centers with different activation energies and capture cross-sections, and very low densities were discovered by the Q-DLTS method. The influence of thermal annealing in air at 100-450°C was investigated. The current leakage and defect concentration were reduced while electrical breakdown field and photoresponse were increased in annealed films. The results obtained have been used for optimization of the technology to prepare thin films with good protective, electrically insulating, and passivating properties.

The parameters of trapping centers in CVD diamond and Diamond-Like Carbon (DLC) films were studied by Charge Deep Level Transient Spectroscopy (Q-DLTS). The concentrations, activation energies, captures cross-section and location of the trapping centers were determined. The influence of post deposition heat treatment on the defect center parameters was studied. The Q-DLTS measurements showed that micro defects are acting as point trapping centers and have the continuous energy spectrum with one or two maximums at different energies. The nature of the trapping centers is discussed.

Reactive Ion Beam Etching (RIBE) has been found to be an extremely useful technique for fabricating highly anisotropic ferroelectric device structures, particularly nonvolatile random access (NVRAM) memory devices, which are difficult to etch by other dry etching methods. The application of ion beam equipment to this field has been limited in the past by the use of standard Kaufman type ion sources, which have very short cathode lifetimes when operated with the reactive gases which are used to attain enhanced selectivity. This problem is solved by using the RF inductively coupled ion source described here. Etch results on ferroelectric PZT and Pt electrodes are presented for the RF source and compared with results for a Kaufman filament ion source. It is shown that RF RIBE with fluorocarbon gases provides higher etch selectivity for the ferroelectric (up to about 4:1 PZT/Pt) combined with relatively high etch rates (650 A/min for PZT at 500 eV). A complete practical ion beam process for patterning ferroelectric device structures is then described, incorporating the ferroelectric RIBE step. Highly anisotropic etched features are shown.