Abstract: A lithium secondary battery which is capable of terminating its operation safely with no accompanying rapid change in appearance, no gas generation, nor pressure change when any of an overcharge, overdischarge, and abnormal temperature rise occurs in the secondary battery itself. The lithium secondary battery includes a negative electrode, which is capable of absorbing and desorbing lithium, a positive electrode, which is capable of absorbing and desorbing lithium, and a non-aqueous electrolyte, wherein the non-aqueous electrolyte is solidified by a thermal reaction at a designated temperature.

Abstract: A multi-color light-emitting element has at least two optical micro-cavity structures having respectively different optical lengths determining their emission wavelengths. Each micro-cavity structure contains a film of or organic material as a light-emitting region, which may be a single film of uniform thickness in the element.

Abstract: A radiation-sensitive material comprising a polyacid composed of tungsten and niobium, titanium and/or tantalum. A uniform film can be formed by an easy spin coating method. The polyacid has a radiation sensitivity higher than that of a polyacid comprising only tungsten.

Abstract: A process for forming a pattern comprising forming an alkali-soluble polymer layer on a substrate, forming a radiation-sensitive composition layer containing a diazonium salt on the alkali-soluble polymer layer to form a resist layer having a two-layer structure, exposing the resist layer to a radiation to cause the change in solubility in an aqueous alkaline solution at the boundary between the two layers and forming a predetermined pattern in the resist layer by a usual resist process. The resist layer may comprise a plurality of layers comprising the two-layer structure as a repeating unit structure.

Abstract: Disclosed is a radiation sensitive composition which comprises a radiation sensitive compound decreased in absorption of radiation upon irradiation with radiation and an organic polymer which, upon being formed into a film, changes in its solubility and decreases in solubility in a desired solvent due to the presence of decomposition product of said radiation sensitive compound which is produced by irradiation with the radiation. A process of formation of pattern using said composition is also disclosed. Fine resist pattern of 0.5 .mu.m line-and-space patterns or less can be formed with sufficiently high contrast.

Abstract: A thick polymer film containing an aromatic bisazide and/or an aromatic sulfonyl azide compound is formed on a substrate having topography level on its surface to flatten said surface and then heated or the whole surface thereof is exposed to a light. A mask pattern having a dry etching resistance higher than that of the polymer is formed on the polymer film, exposed parts of the polymer film are removed by the dry etching and the exposed parts of the film to be processed are removed to form a pattern.

Abstract: A photosensitive composition comprising an azide compound represented by the formula: ##STR1## wherein each of X and Y is an aromatic substituent group, at least one of X and Y being an aromatic substituent group having an azide group, and n and m are zeros or integers of 1, and a polymeric compound. Since this composition has high resolution and is photosensitive to light having a wavelength of 436 nm, it permits employment of a reduction projection printer and is suitable for fabrication of semiconductor devices.

Abstract: There is disclosed a mask for X-ray lithography wherein a peroxopolytungsten compound is used as an absorber, and a process for producing the same. Since this compound has a sensitivity for electron beams and light and serves as an absorber for X-rays, a mask for X-ray lithorgraphy is made only by applying this compound to a substrate, exposing the same to light to form a transferred pattern, and effecting development. Thus, the step of etching the absorber which is essential in the conventional process, is not needed. Therefore, masks having a highly accurate pattern and few defects can be produced with a high production yield.

Abstract: A film of a photoresist having phenolic hydroxyl groups is irradiated with far-ultraviolet radiation, and is thereafter developed with an alkaline aqueous solution. Using as a mask a resist pattern thus obtained, dry etching is carried out to form a microscopic pattern. Since the photoresist is highly immune against the dry etching, the microscopic pattern can be formed at a high precision. By adding an azide of a specified structure, the photoresist has its sensitivity to the far-ultraviolet radiation enhanced more.

Abstract: A negative photoresist having benzene rings is irradiated with short-wavelength ultraviolet radiation, and is developed to form a photoresist pattern whose sectional shape is an inverted trapezoid. Using the photoresist pattern, the lift-off process having heretofore required troublesome steps can be performed very easily.

Abstract: Disclosed is a pattern formation method comprising exposing a photosensitive composition comprising a bisazide compound represented by the following general formula: ##STR1## wherein A stands for an atom or atomic group selected from O, S, CH.sub.2, CH.sub.2 CH.sub.2, SO.sub.2 and S.sub.2, X stands for an atom or atomic group selected from H and N.sub.3, and when X is H, Z is a group of N.sub.3 and when X is N.sub.3, Z is an atom of H or Cl, and a polymeric compound to deep UV rays, to form fine patterns.

Abstract: A radiation-sensitive composition comprising an iodine-containing azide compound at least a part of which can be fixed substantially in a polymer by exposure to a radiation and a polymer, or a radiation-sensitive composition comprising an azide compound, an iodine compound at least a part of which can be fixed substantially in a polymer by exposure to a radiation and a polymer. This composition can be subjected to the dry development with oxygen plasma after the exposure followed by heating.

Abstract: Disclosed is a selective etching method of a polyimide type resin film which uses an etching mask consisting of a negative type photoresist material prepared by adding a photosensitive reagent to an unsaturated ketone polymer such as polymethylisopropenylketone as the base resin and an etching solution consisting of 20 to 40% by volume of hydrazine hydrate and the balance of a polyamine. The etching method of the present invention can provide the pattern of the polyimide type resin film having high dimensional accuracy by wet etching.