Laser plasma deposition

Vacuum deposition techniques, such as sputtering, electron beam evaporation, and plasma deposition are common. Photopolymerization and laser-assisted depositions are used for preparation of specialized layers, particularly in the fabrication of sensing arrays. Most commercial instruments have thickness monitors (Chapter 4) that allow precise control of the deposition process. 

Gorecki C (2000) Optimization of plasma-deposited silicon oxinitride films for optical channel waveguides. Opt Lasers Eng 33 15-20... 

Examples for the second group are polymers as fuel in the micro laser plasma thruster (JJ.LPT), PLD of polymers, matrix-assisted pulsed laser evaporation (MAPLE), which is a deposition technique that can be used to deposit highly uniform thin films [26], or laser-induced forward transfer (LIFT) [27-29], which can be used to produce microstructures by transferring an irradiated area of a target film to an acceptor substrate. The polymer can be the transferred material, or just functions as driving force in the transfer. 

The ordered P AA back-side and structured Al surface were used to produce self-organized metal nanoparticles. We used Au or amorphous carbon as add-layer for deposition of Ti or Fe nanostmctures. Both these metals have a weak wetting of the add-layer. The deposition was performed by a laser induced plasma deposition technique. In this process the energy of ions was about 20 eV. The highly ordered curved substrate surface defined position of the deposited clusters providing formation of highly ordered arrays of metal nanoclusters. A perspective application of such structures for terabit memory was demonstrated. For example, Ti nanoclusters covered by native oxide demonstrated irreversible transformation of I-V characteristics from barrier-like to the ohmic behavior after the action of current supplied by a tip of conductive AFM. 

A good example of the power of synchrotron source radiation is found in the study of the thin-film superconductors that are required for applications of high-temperature superconductors (HTSC) in microelectronics technology [77]. An example of such work [78] involves the analysis of HTSC films produced by laser evaporation of elements in the Y-Ba-Cu-0 system. Ten films were simultaneously deposited with various target-to-substrate distances allowing study to be made of the laser plasma expansion in vacuo. A very important advantage of this method is that it allows extremely low detection limits to be achieved. As an example, in the referenced study [78] the authors claim a detection limit of 5 x lO atoms/cm. ... 

Laser-assisted CVD of BN can originate from a gaseous reactant [58], or the plasma can be formed by irradiating a target consisting mainly of BN [59 to 63, 139]. The cluster distribution of boron nitride in a laser plasma and the structure of the BN phases in the case of laser-induced plasma deposition have been studied [64]. It is also reported that a combination of an electron cyclotron plasma with laser irradiation produces a coating which consists of p-BN and y-BN [65]. 

Figure 3.14 Layout of a laser plasma chemical vapour deposition (CVD) reactor, the gases being introduced to deliver reactants to the substrate surface where plasma was maintained using a CO2 laser.

Much of the energy deposited in a sample by a laser pulse or beam ablates as neutral material and not ions. Ordinarily, the neutral substances are simply pumped away, and the ions are analyzed by the mass spectrometer. To increase the number of ions formed, there is often a second ion source to produce ions from the neutral materials, thereby enhancing the total ion yield. This secondary or additional mode of ionization can be effected by electrons (electron ionization, El), reagent gases (chemical ionization. Cl), a plasma torch, or even a second laser pulse. The additional ionization is often organized as a pulse (electrons, reagent gas, or laser) that follows very shortly after the... 

The requirements of thin-film ferroelectrics are stoichiometry, phase formation, crystallization, and microstmctural development for the various device appHcations. As of this writing multimagnetron sputtering (MMS) (56), multiion beam-reactive sputter (MIBERS) deposition (57), uv-excimer laser ablation (58), and electron cyclotron resonance (ECR) plasma-assisted growth (59) are the latest ferroelectric thin-film growth processes to satisfy the requirements. 

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