CS271925B1 - Method of semiconductor device's p-n junction - Google Patents

Abstract

The method of passivation concerns the fact that 20 to 30 percent by weight of polyamide carboxylic acid with the molecular height of 2.0 to 7.0x10<4> gmol <-1> is applied onto the surface of the component. The drying follows during a period of at least 1 hour at a temperature of 40 to 100 degrees C, eventually in the vacuum and imidisation. The dissolvent to its advantage contains 0.1 to 6.0 percent of cyclopentanone.

Description

(57) The method of passivation consists in applying 20 to 30 wt. solution of polyanidic carboxylic acid having a molecular weight of 2.0 to 7.D.10 ⁴ g · ol ' ^A , followed by heating for at least 1 h at 40 to 100 ° C, optionally under vacuum and inidization. Preferably, the solvent contains from about 0.1% to about 6.0% cyclopentanone.

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CS 271925 Bl

The present invention relates to a process for the single or multiple electron and hole transition of PN semiconductor devices by polyimide-based polymers.

Various inorganic and organic pastry gates are used to achieve stable electrical parameters of these components. By way of example, silica, silicon nitride, alkali-free boron glass, polycrystalline silicon, 'silicones,' epoxides, polyimides, on which they form an adhesive and homogeneous film of defined electro-insulating and dielectric vlaetnoetes, which protects the semiconductor from the environment mechanical handling,

The crucial requirement to create paaivačni vratvy Jaouich abnormally low obaah ion and polarizable impurities 'temperature circumstance ¹ dlelektrlcké characteristics enedné workability, sufficient adhesion to the substrate,' for example to the surface of the silicon oxide and the possibility of forming conductive křemikul oeat like.

These requirements are met to a large extent by a polyimide-based polymer used as a PN-pervious transfer layer, usually with an adhesion promoter and deposited on a carefully cleaned surface and cloths. The advantage of polyimides is its high temperature resistance, better! dielectric parameters than may have inorganic protective layers, ¹ very good barrier properties, better than silicones β possibility of conductive ceat formation, Oako raw materials for synthesis of polyamide polyamide hydroxylic acid precursor polyether amide, are used mainly aromatic acid dlenhydrides and aromatic diemines in which ether bridges are preferred to provide reduced polymer absorption upon sweeping application, which may be combined in suitable molar ratios. After application of a solution of 10 to 15% by weight, the polyamide of the carboxylic acid, for example in Ν, am-dimethylformamide, N-methyl-2-pyrrolidone, isopropanol. of dimethylsulphoxide or N, N-dimethylacetsimide as a component followed by thermal imidization at temperatures of 100 to 400 ° C, while the removal of volatile low molecular weight components and virtually 100% of the imidization process is assumed. Failure to meet these requirements adversely affects the desired properties of the final product, the polyamide film, as it is known that the imidization cycle in this temperature range does not guarantee compliance with the classical claims, particularly since an initial imidization cycle temperature of at least 100 ° C causes rapid formation of a rigid coating. which makes it difficult to diffuse both solvent and condensation water,

The above-described imidization cycle and a polyamide carboxylic acid of undefined molecular weight do not guarantee compliance with the desired polyetide polyimides and, moreover, the polyimide varnish in the above-described solvents may be unstable and thus may change during storage of the latter. When using a concentration in the range of 10 to 15%, the applied polymer solution flows down mainly from the beveled faces of the veneer PN transition of power semiconductor elements.

These drawbacks are eliminated by the PN passivation method of the semiconductor device transitions according to the invention. It is based on the fact that 20 to 30 wt. a polyamide carboxylic acid solution having a molecular weight of 2.10 ⁴ to 7.10 ⁴ g mol ¹ , followed by drying for at least 1 h at temperatures of 40 to 100 ° C, followed by imidization for a longer period.

Preferably, the solvent contains 0.1 to 6.0% cyclopentanone.

The advantage of the process of carrying out the passivation of the PN junction according to the invention is the virtually complete course of imidization, the improved protective properties of the coating, and the greater stability of the polymer solution during storage, which is ensured by the addition of cyclopentonone.

Other advantages of adding cyclopentanone to the solvent system It is easier to remove the solvent during drying by suppressing the interaction between the polymer and the solvent. The use of a polyamide carboxylic acid with a molecular weight of 2.10 ⁴ to 7.10 ⁴ moles ^per liter allows for easier film formation. At the same time, the use of a higher concentration ensures better application of the polymer solution. the possibility of applying a stronger layer and a fine covering of fine edges. No

CS 271925 B1 the polymer solution does not flow off the inclined surfaces.

The method of peeling according to the invention is explained in more detail in the following examples.

Example 1

Power semiconductor diode with one PN junction, where the etched PN junction is treated with N-methylpyrrolidone acetone, then rinsed with deionized water, dried for 0.2 h at 300 ° C and cooled to room temperature, not this surface. 0/1 wt. solution of gaa-aminopropyltrethoxyellan in deionized water, coating ee allowed to react 30 e followed by drying at 110 ° C for 0.5 h. Cooling to room temperature is followed by 23 wt. polyamide carboxylic acid solution formed by reacting pyromellitic acid dienhydride and 4,4-dianinodiphenylmethane with a molar mass

70.10 ³ gmol ^-1 in N-methylpyrrolidone e 1 ', 5 wt. cyclopentanone. This is followed by drying under vacuum at a pressure of 1 kPa, 60 ° C for 5 h and curing under a nitrogen atmosphere at 150 ° C, baking at 200 ° C and finally at 300 ° C, for 1 hour each.

Example 2

The power semiconductor thyristor is a PN junction where the etched PN junction is treated with a mixture of dimethylene sulfide oxidation to n, then rinsed with pure methanol, dried for 0.5 h at 250 ° C and cooled to room temperature. naneeen 0/6% wt. a solution of gamma-aminopropyltriethoxyeilene in propanol-water / coating was allowed to react for 15 h, followed by heating at 90 ° C for 1 h. After cooling to room temperature, 20 wt. solution of polyamide of carboxylic acid formed by reaction of pyromellitic acid dianhydride and 4/4-diaminodiphenylmethane with a molar mass of 55.10 gmol in dimethylsulfoxide. This is followed by drying at 76 ° C for 10 hours and curing at 180 ° C, then baking at 250 ° C and finally at 350 ° C, for 1 hour each.

Example 3

Power semiconductor diode 8 with a single PN junction ^: wherein the etched PN junction is treated with a mixture of N-methylpyrrolidonecetone, then rinsed with deionized water, dried for 0.5 h at 300 ° C and cooled to room temperature, applied to this surface. 3 wt.%, A solution of .alpha.-aminopropyltrlethoxysilene in isopropanol-water, ¹ coating was allowed to react for 60 e, followed by drying at 120 DEG C. for 0.5 h. After cooling to room temperature, 27 wt. solution of the polyamide carboxylic acid formed by the reaction of dianhydride;

% of pyromellitic acid and 4,4-diaminodiphenyl ether with a molar mass of 35.10 gmol in N-methylpyrrolidone β 1.5% by weight, cyclopentanone. Drying is then carried out for 2 hours at 50 ° C and 4 hours at 100 ° C β, cured in a nitrogen atmosphere at 150 ° C, then at 200 ° C β, finally at 300 ° C, for 1 hour and 30 minutes. at 400 ° C.

Example 4

Power semiconductor thyristor with three PN junction, where the etched PN junction is treated with dimethylsulfoxide acetone, then rinsed with ethanol, dried for 40 min. at 0 '

280 C e cooled to room temperature, 0.8% wt. solution of gem-aminopropyl-triethoxy-7-ethylene in decanted ethanol-water was allowed to react for 20 s, followed by drying at 130 ° C for 15 min. Cooling to room temperature is followed by 30 wt. solution of polyamide carboxylic acid formed by reaction of pyromellitic dianhydride and 4,4-diaminodiphenyl ether with a molar mass of 20.10 ³ gmol ^-1 in a mixture of N-methylpyrrolldone with 4 wt. cyclopentanone. This is followed by drying for 3 hours at 80 ° C β curing in a nitrogen atmosphere at 170 ° C, then at 250 ° C and finally at 360 ° C for 1 hour each.

The method according to the invention can be used in semiconductor technology.

Claims (2)

OBJECT OF THE INVENTION 1 · Process for the PN transition of a polyimide polyimide polymer semiconductor component based on a polyamide carboxylic acid solution eynthesized from an aromatic acid dianhydride and an aromatic diamine in a solvent of N-methyl-2-pyrrolidone, N ' -dimethylformamide * 20 to 30% by weight of a solution of polyamide carboxylic acid having a molecular weight of 2 * 0 to 7 * 10 * 10 ⁴ gmol followed by drying for at least 1 hour at temperatures of 40 to 100 ° C, followed by Imldlzace * 2 * The method of carrying out the PN junction of the semiconductor eucalyptus according to item 1 * ^{1 is} characterized by. characterized in that the solvent contains 0% to 6.9% cyclopentanone.