Polyimide deposition

In this report we use XPS to compare the interfacial interactions for a set of model molecules for polyimide, deposited in UHV upon vapor-deposited polycrystalline copper substrates. 

Polyimide Deposition. The most accurate processes for depositing thin, uniform coatings of PAA or PI solutions are spin coating, spray coating, and a recently reported screening process (12). 

POLYIMIDE DEPOSITION PHOTOLITHOGRAPHY - POLYIMIDE HIGH TEMPERATURE POLYIMIDE BAKE (700°C)... 

POLYIMIDE deposition PHOTOLITHOGRAPHY - POLYIMIDE SOURCE-DRAIN CONTACT ETCH ALUMINUM DEPOSITION PHOTOLITHOGRAPHY ANNEAL (400°C)... 

The Langmuir-Blodgett films (LB films) of polyimides deposited on substrates prove to be useful for aligning FLC molecular axes parallel to the transfer direction without rubbing. High-quality alignment promoting the appearance of bistable states has been reported [136]. 

With the increase in packing density of dynamic RAMs, soft errors caused by alpha particles are becoming an increasingly important cause of device malfunctioning. (For further information on soft errors see Section 10.3.) Alpha particles are emitted from uranium and thorium isotopes residual in most packaging materials and thin films of polyimides deposited upon a chip surface have been successfully evaluated as alpha particle barriers. Polyimides can be made pure enough to contain no detectable amounts of uranium or thorium and a 40 xm thick film may reduce the soft error generation rate by up to 1000 times. A typical example of a commercially available polyimide alpha particle barrier is DuPont s Pyralin PIH 61454. 

A number of dielectric films are deposited by the spin-on technique. In this case the film s constituent molecules are dissolved in a solvent to form a hquid. After spinning the Hquid over a semiconductor surface the solvent is driven off with a baking step, leaving behind the thin dielectric film. Common films include polyimide and benzocyclobutene (BCB). The deposition process for these films is simple, making it attractive for a manufacturing process. 

Many authors have used XPS to investigate the mechanisms by which vapor-deposited metals such as copper interact with the surfaces of polyimides. Chou and Tang [29] observed that only small changes occurred in the XPS line shapes after vapor deposition of copper on polyimide they suggested that no... 

After deposition of 0.5 nm of copper onto plasma modified polyimide, the peaks due to carbon atoms C8 and C9 and the oxygen atoms 03 and 04 were reduced in intensity, indicating that new states formed by the plasma treatment were involved in formation of copper-polyimide bonds instead of the remaining intact carbonyl groups. Fig. 28 shows the proposed reaction mechanism between copper and polyimide after mild plasma treatment. 

Adhesion of copper films to PMDA/ODA polyimide was determined by peel tests conducted on samples that were prepared by vapor-depositing a thin layer of copper onto the polyimide and then building the thickness of the metal layer to about 18 p,m by electrodeposition of copper. Results of the adhesion measurements correlated well with substrate pretreatment. When the substrate... 

In fact, the 4- or 3-aminophthalic anhydride (4-APA and 3-APA) gives only intractable oligomers as pointed out later.154 Interesting are the attempts of vapor-phase deposition of 4-APA, 3-APA, and 4-amino naphtlialic anhydride (4-ANA). The sublimation of 3-APA gives only a low yield of polyimide. With both 4-APA and 4-AN A no sublimation took place and oligomeric products were formed before melting.154... 

Vapor-phase deposition polymerization polyimide synthesis by, 303 PQ and PPQ synthesis by, 312... 

A schematic cross-section of a p-i-n a-Si H solar cell [11] is shown in Figure 72a. In this so-called superstrate configuration (the light is incident from above), the material onto which the solar cell structure is deposited, usually glass, also serves as a window to the cell. In a substrate configuration the carrier onto which the solar cell structure is deposited forms the back side of the solar cell. The carrier usually is stainless steel, but flexible materials such as metal-coated polymer foil (e.g. polyimid) ora very thin metal make the whole structure flexible [11]. 

Fig. 6.13. The kinetics of bending of polyimide film with deposited silver (/) and emission of O-atoms (2) when oxygen is let inside the vial.

Hence, Tct is seen to increase with pore density and pore radius. However, a problem appears at a porous substrate when thin films are to be deposited during metallization to form interconnections, thin-film capacitors, etc.335 Sputtered material falls deep into the pores, which affects the planarity of the deposited layer and the electrical resistivity of the oxide layer underneath.335 To cope with this effect, the porous oxide should be padded by inorganic (A1203 and Si02) or organic (polyimide, negative photoresist) layers. 

Figure 12.12 Image of an organo-metallic palladium precursor solution that was deposited by the author on a flexible polyimide substrate via spin coating and thermally processed at 200 °C for 30 seconds.

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