Load-lock

There are several types of deposition chamber configurations (Fig. 2). The batch-type system is the most commonly used, but the requirement that the system be returned or let-up to ambient pressure on each cycle can pose problems in obtaining a reproducible processing environment. The load-lock system and the in-line system allows the deposition chamber to be kept under vacuum at all times and the substrates introduced and removed through... 

Fig. 2. Vacuum processing chamber configuration (a) batch coater (b) load-lock coater (c) in-line coater (d) cluster tool (e) roU coater (batch) and (f) roU coater (air-to-air), [[ccsq]] represents the isolation valve with transfer tooling [[artl]], the motion of fixturing and [[art2]], the access door.

Commercial spectrometers are usually bakeable, can reach ultrahigh-vacuum pressures of better than 10" Torr, and have fast-entry load-lock systems for inserting samples. The reason for the ultrahigh-vacuum design, which increases cost considerably, is that reactive surfaces, e.g., clean metals, contaminate rapidly in poor vacuum (1 atomic layer in 1 s at 10 Torr). If the purpose of the spectrometer is to always look at as-inserted samples, which are already contaminated, or to examine rather unreactive surfaces (e.g., polymers) vacuum conditions can be relaxed considerably. 

The two processes are becoming closer in concept. For instance, MOCVD is using techniques developed for MBE such as in situ characterization monitoring, load lock, and lower pressure levels, and MBE is now using chemical sources such as organome-tallics, which are typical of CVD. 

The etch experiments were performed using a commercial ICP etcher equipped with an ICP source and a load lock. The substrate susceptor was cooled by He through a chilled fluid. The coil, which was connected to a 13.56 MHz RF power supply, was located on the lid of a ceramic chamber to generate a high density plasma. A bias voltage induced by RF power at... 

Electrocatalytic activity of supported metal particles has been investigated on surfaces prepared in an ultrahigh vacuum (UHV) molecular beam epitaxy system (DCA Instruments) modified to allow high throughput (parallel) synthesis of thin-film materials [Guerin and Hayden, 2006]. The system is shown in Fig. 16.1, and consisted of two physical vapor deposition (PVD) chambers, a sputtering chamber, and a surface characterization chamber (CC), all interconnected by a transfer chamber (TC). The entire system was maintained at UHV, with a base pressure of 10 °mbar. Sample access was achieved through a load lock, and samples could be transferred... 

By using a multichamber system [129], exchange of residual gases between successive depositions will be strongly decreased, and very sharp interfaces can be made. Furthermore, the use of a load-lock system ensures high quality of the background vacuum, and thus low levels of contaminants in the bulk layers. Multichamber reactor systems have been used for the fabrication of solar cells, and considerable improvements in energy conversion efficiency have been achieved [130, 131]. 

Hot reactor walls are sometimes used as a means to increase the density of the films that are deposited on the walls. This reduces the amount of adsorbed contaminants on the walls, and leads to lower outgassing rates. A hot wall is particularly of interest for single-chamber systems without a load-lock chamber. Material quality is similar to the quality obtained with a cold reactor wall [145],... 

FIG. 5. Schematic representation of the ASTER deposition system. Indicated are (I) load lock. (2) plasma reactor for intrinsic layers. (3) plasma reactor for />-type layers. (4) plasma reactor for t -type layers, (5) metal-evaporation chamber (see text). (6) central transport chamber. (7) robot arm. (8) reaction chamber, (9) gate valve, (10) gas supply. (11) bypass. (12) measuring devices, and (13) tur-bomolecular pump. 

The deposition chamber is a cylindrical vessel with a diameter of 50 cm and a length of 80 cm. At about 5 cm from the arc outlet, silane can be introduced via an injection ring (7.5-cm diameter) that contains eight holes of 1-mm diameter each. The distance between arc outlet and substrate is 38 cm. The substrates are heated via the substrate holder, of which the temperature can be controlled between 100 and 500°C. Samples can be loaded via a load lock equipped with a magnetic transfer arm. The substrate can be optionally RF-biased. A residual gas analyzer... 

Figure 6. Plan of the target preparation facilities consisting of UHV preparation chamber (a), (reactive) ion etching chamber (b), ion etching gun (c), laser (d), photon detector (e), transfer arms (f), Auger system for surface analysis (g), sample manipulator and annealing facility (h), load lock and optical microscope for viewing sample (i), evaporator (j), transmission diffractometer (k), and vacuum tank for main spectrometer (1).

Loading waveform, 13 482-483 Load limits, in waste collection, 25 870 Load-lock system, 24 724 Load variable, 20 666 Lobeline, 2 82... 

UHV surface preparation and analysis chamber, a variable pressure STM chamber, and a load lock and sample transfer system. Fig. 11 shows a schematic of the system. 

Figure 19-2. Schematic overview of the type of apparatus used to investigate the desorption of ions and neutral species induced by electron impact on thin molecular and bio-organic films. In the case of thin DNA films, they are formed outside vacuum by lyophilization on a metal substrate or as a self-assembled layer. The films are placed on the multi-sample holder in the load-lock chamber. From there, they can be transferred one by one to the main chamber for analysis...

The metal-on-polymer interface has been the most studied Interface as metals can conveniently be deposited by evaporation in situ 1n a controllable fashion in a UHV system (26-33). In the case of polyimide, Cu and Cr have been the most studied metals but other metals including N1, Co, Al, Au, Ag, Ge, Ce, Cs, and Si have been studied. The best experimental arrangement includes a UHV system with a load lock Introduction chamber, a preparation chamber with evaporators, heating capabilities, etc., and a separate analysis chamber. All the chambers are separated by gate valves and the samples are transferred between chambers under vacuum. Alternative metal deposition sources such as organometall1c chemical vapor deposition are promising and such techniques possibly can lead to different interface formation than obtained by metal evaporation(34). 

The model molecules which are solid at room temperature (except for benzene), were evaporated from a source consisted of a borosilicate glass container with a small opening, like the design of a Knudsen cell. The source was mounted inside a heatable and coolable copper shaft, that could be inserted to the vaccum system through a load-lock arrangement. Upon heating, the pressure was... 

Fig. 11.5. Sketch of the MAJESTIX setup. The vacuum system is divided into a preparation chamber and a particle-beam chamber, separated by a gate valve. The preparation chamber is also used as load lock. The main components in the particle-beam chamber are the ion gun system, comprising a Wien filter and deceleration...

The polymer films were solvent cast on stainless steel substrates and air dried at 22C their final thickness was about 0.001 mn. After insertion into the ultra-high vacuum chamber througji a load-lock chamber, the polymers were warmed to temperatures above their respective glass transition temperatures for the time needed to remove the remaining solvent from the bulk of the film. 

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