GB1585477A - Semiconductors - Google Patents
Semiconductors Download PDFInfo
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- GB1585477A GB1585477A GB1219/77A GB121977A GB1585477A GB 1585477 A GB1585477 A GB 1585477A GB 1219/77 A GB1219/77 A GB 1219/77A GB 121977 A GB121977 A GB 121977A GB 1585477 A GB1585477 A GB 1585477A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
- H01L21/02123—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon
- H01L21/02126—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
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- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
- H01L21/02282—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
- H01L21/02318—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment
- H01L21/02337—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment treatment by exposure to a gas or vapour
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
- H01L23/29—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the material, e.g. carbon
- H01L23/293—Organic, e.g. plastic
- H01L23/296—Organo-silicon compounds
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
- H01L23/31—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape
- H01L23/3157—Partial encapsulation or coating
- H01L23/3171—Partial encapsulation or coating the coating being directly applied to the semiconductor body, e.g. passivation layer
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- H—ELECTRICITY
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
- H01L23/31—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape
- H01L23/3157—Partial encapsulation or coating
- H01L23/3178—Coating or filling in grooves made in the semiconductor body
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
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- H—ELECTRICITY
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/10—Details of semiconductor or other solid state devices to be connected
- H01L2924/11—Device type
- H01L2924/12—Passive devices, e.g. 2 terminal devices
- H01L2924/1204—Optical Diode
- H01L2924/12044—OLED
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- Computer Hardware Design (AREA)
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- Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
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- Structures Or Materials For Encapsulating Or Coating Semiconductor Devices Or Solid State Devices (AREA)
Abstract
The novel semiconductor device comprises a body made of semiconductor material having at least two regions of opposite conductivity type. Between the regions of opposite conductivity type there is a P-N junction. An end part of at least one P-N junction is exposed on the surface of the body and has a layer of protective coating material directly on the surface of the body and the exposed end part. The protective coating material is a cured reaction product of a silicon-free organic diamine, an organic tetracarboxylic dianhydride and a polysiloxane containing amine terminal groups. It contains repetitive structural units of the following formula: <IMAGE> containing 15 to 40 mol% of intercondensed structural units of the following formula <IMAGE> R, R', R'', Q, x, n and m are defined in the preceding Patent Claim 1.
Description
(54) IMPROVEMENTS IN SEMICONDUCTORS
(71) We, GENERAL ELECTRIC COMPANY, a corporation organized and existing under the laws of the State of New York, United States of America, of 1
River Road, Schenectady 12305, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to improvements in semiconductors and in particular to copolymers as protective coating materials for semiconductor elements.
Heretofore, some prior art methods provide coating at least preselected exposed surface areas of semiconductor elements with electrically insulating oxide materials. Such coatings are thin layers and have virtually no resistance to mechanical abrasion and require relatively expensive processing equipment. In almost all instances a second and thicker coat of a protective coating material is provided to protect the initial electrically insulating material. Silicone greases, varnishes, rubbers and resins which are employed as the overcoating of protective material have been found lacking in desirable physical characteristics.
The present invention provides a semiconductor element comprising a body of semiconductor material; at least two regions of opposite type conductivity formed in the body; a P-N junction disposed between and formed by the abutting surfaces of each pair of regions of opposite type conductivity; an end portion of at least one P-N junction exposed at a surface of the body; a layer of a protective coating material disposed directly on the surface of the body and the exposed end portion of at least one P-N junction; the protective coating material being a copolymer material which is a reaction product of a silicon-free organic diamine, an organic tetra carboxylic dianhydride and a polysiloxane diamine which when cured has recurring structural units of the formula:
with from 15 to 40 mol percent intercondensed structural units based on the total number of units of the formula:
wherein:
R is a divalent hydrocarbon radical;
R' is a monovalent hydrocarbon radical;
R" is a tetravalent organic radical;
Q is a divalent silicon-free organic radical which is the residue of an organic
diamine;
and
x is an integer having a value of 1--4.
The present invention also provides a semiconductor element wherein the protective coating is formed from a solution of a polymeric material comprising a copolymer material which is a reaction product of a silicon-free organic diamine, either 2,2-bis [4-(3,4-dicarboxyphenoxy)phenyl] propane dianhydride or 2,2-bis [4 (2,3-dicarboxyphenoxy)phenyl] propane dianhydride, and an amine capped polysiloxane, the reaction product having recurring structural units of the formula:
with from 15 to 40 mol percent intercondensed structural units based on the total numbers of units of the the formula:
wherein:
R is a divalent hydrocarbon radical;
R' is a monovalent hydrocarbon radical;
R" is the tetravalent residue of ether 2,2-bis [4-(3,4-dicarboxyphenoxy)
phenyl] propane dianhydride or 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]
propane dianhydride;
Q is a divalent silicon-free organic radical which is the residue of an organic
diamine;
and
x is an integer having a value of 1 to 4 and a solvent.
The number of units in formulae I and II may be in the range 10 to 10,000 or more.
The present invention will be further described, by way of example only, with reference to the accompanying drawings in which: FIGURES 1, 2 and 3 are side elevation views, in cross-section of a semiconductor element processed in accordance with the teachings of this invention.
FIGURE 4 is a top planar view of the element of FIGURE 3.
FIGURES 5 and 6 are side elevation views, in cross-section, of portions of semiconductor elements.
With reference to FIGURE 1, there is shown a semiconductor element 10 comprised of a body 12 of semiconductor material. The body 12 is prepared by suitable means, such for example, as by polishing and lapping to parallelism two opposed surfaces 14 and 16. The body 12 has two or more regions of opposite-type conductivity and a P-N junction formed by the abutting surfaces of each pair of regions of opposite-type conductivity. The end portion of at least one P-N junction is exposed in a surface of the body 12. The body 12 comprises a suitable semiconductor material such, for example, as silicon, silicon carbide, germanium, compounds of Group II and Group VI elements and compounds of Group III and Croup V elements.
In order to more fully describe the invention and for no other purpose, the body 12 will be described as being comprised of silicon semiconductor material having five regions of conductivity and four P-N junctions. Such a configured element 10 may function as thyristor. Therefore, the body 12 has regions 18 and 20 of P-type conductivity, a region 19 of P±type conductivity, and regions 22, 24, and 26 of N-type conductivity. P-N junctions 28, 30, 32 and 34 are formed by the abutting surfaces of the respective pairs of regions 18 and 22, 22 and 20, 20 and 24, and 20 and 26 of opposite-type conductivity.
One means of controlling the surface electric field on such a controlled rectifier is to contour the side surface 36 after affixing the partially processed body 12 to a large area contact 38 by a layer 40 of a suitable ohmic electrical solder.
Electrical contacts 42 and 44 are affixed to the respective regions 24 and 26. As illustrated, the contouring of the surface 36 results in the well known "double bevel" surface.
Referring now to FIGURE 2 there is shown a semiconductor element 50 embodying a double positive bevel configuration for controlling the surface electric field. All items denoted by the same reference numbers as those in Element
10 of Figure 1 are the same and function in the same manner as the corresponding item in Element 10. Element 50 functions as a thyristor for the configuration illustrated. Regardless of the method employed to control the surface electric field, selected end portions of at least some of the P-N junctions are exposed at surface areas of the body 12. It is necessary therefore to apply a suitable material to protect the exposed end portions of the P-N junctions.
A layer 46 of a protective coating material such, for example, as a polyimidesilicone copolymer is disposed on at least the surface 36 and the exposed end portion of at least the P-N junctions 28 and 30. The protective coating material may be disposed on the surface 36 as a polymer precurser dissolved in a suitable solvent. Upon heating, or by evaporation at room temperature, the protective coating material of the layer 46 is polymerized in situ on the surface 36 and the end portion of at least one P-N junction. Preferably, the material of the layer 46 is applied to the preselected surface area of the surface 36 of the body 12 as a solution of a polymeric intermediate. Application of the material to at least the surface 36 of the body 12 is practiced by such suitable means as spraying, spinning, brushing, screen printing, and the like. The body 12 with the applied protective coating material is then heated to convert the resinous soluble polymer intermediate to a cured, solid, and selectively insoluble material.
The protective coating material of the layer 46 is preferably one which, when cured, exhibits excellent adhesion to the surface 36. Additionally, the material should exhibit good abrasion resistance and resistance to the chemical reagents utilized in finishing the fabrication of the device 10.
A suitable material for forming the layer 46 and meeting the aforesaid requirements is the reaction product of a silicon-free organic diamine, an organic tetracarboxylic dianhydride and a polysiloxane diamine which is a polymer precurser soluble in a suitable organic solvent. On curing, it yields a copolymer having recurring structural units of the formula:
with from 15 to 40 mol percent and preferably 25 to 35 mol percent intercondensed structural units of the formula:
wherein R is a divalent hydrocarbon radical, R' is a monovalent hydrocarbon radical, R" is a tetravalent organic radical, Q is a divalent silicon-free organic radical which is the residue of an organic diamine, and x is an integer having a value of 14.
The above-mentioned block copolymers can be prepared by effecting reaction, in the proper molar proportions, of a mixture of ingredients comprising a diamino-siloxane of the general formula:
a silicon-free diamino compound of the formula: NH2-Q-NH2 and a tetracarboxylic acid dianhydride having the formula:
wherein R, R', R" Q and x have the meanings given above.
It will be recognized that the ultimate polyimide-siloxane composition used in the practice of this invention will consist essentially of the imido structures found in
Formulas I and II. However, the actual precursor materials resulting from the reaction of the diamino siloxane, the silicon-free organic diamine and the tetracarboxylic acid dianhydride will initially be in the form of a polyamic acid structure composed of structural units of the formula:
where R, R', R", Q and x have the meanings given above.
The diamino siloxanes of Formula III which may be used in the practice of the present invention include compounds having the following formulas:
and the like.
The diamines of Formula IV above are described in the prior art and are to a large extent commercially available materials. Typical of such diamines from which the prepolymer may be prepared are the following: m-phenylenediamine; p-phenylenediamine; 4,4'-diaminodiphenylpropane; 4,4'-diaminodiphenylmethane (hereinafter referred to as "methylenedianiline") benzidine;* 4,4'-diaminodiphenyl sulfide; 4,4'-diaminodiphenyl sulfone; 4,4'-diaminodiphenyl ether; 1 ,5-diaminophthalene; 3,3'-dimethylbenzidine; 3,3'-dimethoxybenzidine; 2,4-bis (p-amino-t-butyl)toluene; bis(p-pamino-t-butylphenyl)ether; bis(p-p-methyl-o-aminopentyl)benzene; I ,3-diamino-4-isopropylbenzene; 1 ,2-bis(3-aminopropoxy)ethane; m-xylylenediamine; p-xylylenediamine; bis(4-aminocyclohexyl)methane; decamethylenediamine; 3-methylheptamethylenediamine; 4,4-dimethylheptamethylenediamine; 2,11-dodecanediamine; 2,2-dimethylpropylenediamine; actamethylenediamine; 3-methoxyhexamethylenediamine; 2,5-dimethylhexamethylenediamine 2,5-dimethylheptamethylenediamine; 3-methylheptamethylenediamine; *We make no claim to the use of benzidine in contravention of the carcinogen substances Regulations 196) 5-methylnonamethylenediamine; 1,4-cyclohexanediamine; 1,12-octadecanediamine; bis(3-aminopropyl)sulfide;
N-methyl-bis(3-aminopropyl)amine; hexamethylenediamine; heptamethylenediamine; nonamethylenediamine; and mixtures thereof. It should be noted that these diamines are given merely for the purpose of illustration and are not considered to be all-inclusive. Other diamines not mentioned will readily be apparent to those skilled in the art.
The tetracarboxylic acid dianhydrides of Formula V may further be defined in that the R" is a tetravalent radical, e.g. a radical derived from or containing an aromatic group containing at least 6 carbon atoms characterized by benzonoid unsaturation, wherein each of the 4 carbonyl groups of the dianhydride are attached to a separate carbon atom in the tetravalent radical, the carbonyl groups being in pairs in which the groups in each pair are attached to adjacent carbon atoms of the R radical or to carbon atoms in the R" radical at most one carbon atom-atom removed, to provide a S-membered or 6-membered ring as follows:
Illustrations of dianhydrides suitable for use in the present invention (with their reference designation in parenthesis)include: pyromellitic dianhydride (PMDA); 2,3,6,7-naphthalene tetracarboxylic dianhydride; 3,3,4,4'-diphenyl tetracarboxylic dianhydride; 1,2,5,6-naphthalene tetracarboxylic dianhydride; 2,2',3,3'-diphenyl tetracarboxylic dianhydride; 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride; bis(3,4-dicarboxyphenyl)sulfone dianhydride; 2*2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (B PA dianhydride); 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane d ianhydride; benzophenone tetracarboxylic acid dianhydride (BPDA); perylene-1,2,7,8-tetracarboxylic acid dianhydride; bis (3,4-dicarboxyphenyl)ether dianhydride, and bis(3,4dicarboxyphenyl)methane dianhydride; and aliphatic anhydrides such as cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, etc. The incorporation of other anhydrides, such as trimellitic anhydride, to make amide-imide-siloxane polymers is not precluded.
Application of the block copolymers or blends of polymers in a suitable solvent (including, for example, N-methyl-2-pyrrolidone, N,N-dimethylacetamine,
N,N-dimethylformamide, etc.) alone or combined with non-solvents, to the substrate material may be by conventional means such as dipping, spraying, painting and spinning. The block copolymers or blends of polymers may be dried in an initial heating step at temperatures of about 75 to 1500C for a sufficient time frequently under vacuum to remove the solvent. The polyamic acid is then converted to the corresponding polyimide-siloxane by heating at temperatures of about l500-3000C for a sufficient time to effect the desired conversion to the polyimide structure and final cure.
A preferred curing cycle for materials of the above general formula is as follows:
(a) from 15 to 30 minutes of from 135"C to 1500C in dry N,.
(b) from 15 to 60 minutes at about 185"C + 10 C in dry N2.
(c) from 1 to 3 hours at about 225"C in vacuum.
Alternately, it has been found that one may be able to cure the coating material in other atmospheres such as, for example, as air for ease of commercial application of this invention.
In particular, a solution of the polymerprecurser in the form of the polyamic acid form dissolved in N-methyl pyrrolidone containing 25% solids weight is prepared in the following manner:
To a reaction flask flushed by nitrogen is charged the following chemical ingredients:
401.25 grams N-methyl-2-pyrrolidone
18.6 grams 1 ,3bis(y-aminopropyl)tetramethyldisiloxane 34.65 grams methylenedianiline
The reaction mixture is stirred until a homogeneous mixture is reasonably assured. To the mixture 80.50 grams of benzophenone tetracarboxylic acid dianhydride is added while the mixture is stirred continuously. Stirring is continued for a period of about 5 hours to obtain a homogeneous fluid. The fluid is very resinous and the length of time of stirring assures completion of the reaction of the chemical constituents therein.
Sufficient material is applied to the surface 36 to provide a layer 46, the thickness of which is from 1 micron to 100 microns. The minimum thickness is determined by the requirement that the cured material prevent the penetration of the ambient moisture and sodium ion contamination through the layer 46 to the silicon of the surface 36 and to afford the surface 36 good protection from damage by abrasion action. Additionally, when used as an overcoating of oxide passivated devices, the minimum thickness is that giving the necessary spatial isolation between surface ion contamination and the underlying p-n junction.
It is desirable that the material of the coating 46 be applied to the surface 36 as a precursor. The precursor consists of resinous material in a suitable solvent. It has been found that a precursor wherein from 10 percent to 40 percent solids by weight are contained therein is suitable for semiconductor work. Preferably the precursor has from 20 to 40 percent solid resinous material contained therein.
Referring now to FIGURES 3 and 4, there is shown a semiconductor element 110 embodying the polymeric material of this invention. The element 110 comprises a body 112 of semiconductor material. The body 112 is prepared by suitable means, such, for example, as by polishing and lapping to parallism two opposed surfaces 114 and 116. The body 112 has three regions 118, 120 and 122 of alternate and opposite type conductivity. The region 122 may be of the two regions 124 and 126 of like conductivity but each of a different level of resistivity. P-N junctions 128 and 130 are formed by the abutting surfaces of the respective regions 118 and 120 and 120 and 124 of opposite type conductivity. The element 110, as illustrated, is to function as a transistor wherein region 118 is an emitter, region 120 is the base and region 120 is the collector.
Electrical contacts 132, 134 and 136 a're affixed to respective regions 118, 120 and 136 which function respectively as the emitter, base and collector contacts. A layer 138 or a thermally grown oxide such, for example, as silicon dioxide or deposited coatings such as aluminum oxide, silicon nitride or aluminum nitride, is disposed on the remainder of the surface 114. An electrical isolation groove 140 is formed in the body 112 and extends from the top surface 114 downwardly through the region 120, across P-N junction 130, through region 124 into region 126. The groove 140 in the outer peripheral portion of the element 110 helps control the electrical properties of the element 110. 142 is a polymer material disposed in the surfaces of the groove 140.
With reference to FIGURE 5, when the element 110 is an NPN transistor, the material of the layer 46 has been found to provide an excellent means for stabilizing the electrical characteristics of the element 110. As shown inFIGURE 5, in the operating mode, mobile sodium ions, as a contaminant, are present on the surface 144 of a passivation layer 138 of silicon dioxide as indicated by the plus signs thereon. The layer 138 is approximately 3000A in thickness. As a result of the presence of the mobile sodium ions channel formation 143 is induced in the P region 120, across P-N junction 128, through region 118 to the surface 114.
Consequently, the element 110 exhibits a higher leakage current and low, irreversible breakdown voltages.
Referring now to FIGURE 6, a thin layer 146 of the polymeric material, described heretofore with respect to the material comprising the layer 46 of the element 10 layer 146 of the element 110, is disposed on the surface 144 of the layer 138. The thickness of the layer 146 is, like layer 46, from about 1 micron to 100 microns. As a result of the layer 146, the effect of the mobile ions is substantially reduced. Current leakage is very small in comparison to the uncoated element and voltage breakdown greatly enhanced and more than doubled in value. It is believed that the material of the layer 146 immobilizes some of the mobile ions and displaces the remainder by causing them to be spaced further from the surface 114 of the element 110 than they previously were as shown in FIGURE 5.
Other advantages of the use of the material of the layer 146 have been discussed. The cured polymeric material is able to withstand temperatures of about 450"C. This beneficial result enables one to passivate the element 110 prior to mount down and lead bonding. Thus the element 110 is protected from contamination during relatively dirty processing operations.
It is believed, also, that the siloxane, or silicone, portion of the polymer is acting as an adhesion promoter. Therefore, very small amounts thereof may be satisfactory and the molar proportion of the siloxane portion present in the polymer may be as low as 7.5 percent.
In order to illustrate the teachings of this invention, high voltage power transistors were prepared using state-of-the art planar technology. The transistor configuration illustrated in FIGURES 3 and 4 is of a mesa configuration with the collector-base junction exposed at the surface of an etched moat. These transistors are.passivated by applying the polymer precurser solution selectively in the moat area to coat any exposed silicon in the structure. A solution of the polymer precursor in the form of the polyamic acid form dissolved in N-methyl-2pyrrolidone containing 25 percent solids by weight was disposed on the surface of each body in which end portions of P-N junctions were exposed.
The polymer precursor solution was formed by reacting benzophenone tetracarboxylic acid dianhydride with methylene dianiline and bis(yaminopropyl)tetramethyl-disiloxane, the latter two diamine materials being present in the molar ratio of 70:30. The reaction was carried out at a temperature of less than 50"C and using suitable purified and dried materials to favor a large molecular weight polymer.
The protective coating material was cured in three stages of heating. Each coated device or wafer was heated to a temperature of 135"C + 5"C for 20 minutes in an atmosphere of dry nitrogen gas. At the completion of this process time, the temperature was raised to 1850C + 5"C and the devices held at temperature in dry nitrogen gas for 30 minutes, whereupon the material is then heated for at least 1 hour in a vacuum at 2250C.
An examination of the cured coatings showed them to be clear and free of bubbles. All the devices were evaluated electrically. The coated devices showed superior electrical characteristics. Measurements of reverse leakage and base to collector breakdown voltage (BVCBO) gave repeatable values 800 volts which approached the theoretical value expected for the 20-40 Q cm n- material used showing that bulk breakdown rather than surface breakdown was occurring.
Leakage levels under reverse bias conditions at voltages approaching breakdown
were - I A at room temperature (collector area - 0.4 cm2).
In contrast, similar devices but uncoated shown reverse leakage - 0.1 mA at several hundred volts and breakdown irreversibly at voltage of 200-400 volts.
The dielectric constant for the cured material of the coating 46 was 3.0. The dielectric strength was 400 volts per micrometer for a material thickness of 2.4,us.
The bulk resistivity of the cured material was 10'7 ohm-cm at 250C. The surface charge of the cured material was 1.8 x 10" per square cemtimeter and positive.
The coated devices were soaked in tap water for 12 hours with negligible effect on its operating characteristics. Sustained reverse bias of the element caused no change in reverse leakage current for periods of up to about 6 hours at a temperature of approximately 90"C.
When the silicone content of the material is from 25 to 35 mol percent, excellent physical and electrical properties are obtained. The material exhibits excellent adhesion to the surface of the semiconductor material. Additionally, the cured material has excellentg abrasion resistance and forms an excellent moisture and mobile ion barrier seal for the element.
The above features make the material of this invention superior to the prior art material. Further, its ease of application as a one-part component and simple curing cycle enhance its adaptability to manufacturing processing in the semiconductor industry.
WHAT WE CLAIM IS:
1. A semiconductor element comprising a body of semiconductor material; at least two regions of opposite type conductivity formed in the body; a P-N junction disposed between and formed by the abutting surfaces of each pair of regions of opposite type conductivity; an end portion dfat least one P-N junction exposed at a surface of the body; a layer of a protective coating material disposed directly on the surface of the body and the exposed end portion of at least one P-N junction; the protective coating material being a copolymer material which is a reaction product of a silicon-free organic diamine, an organic tetra carboxylic dianhydride and a polysiloxane diamine which when cured has recurring structural units of the formula:
with from 15 to 40 mol percent intercondensed structural units of the formula:
wherein:
R is a divalent hydrocarbon radical;
R' is a monovalent hydrocarbon radical;
R" is a tetravalent organic radical;
Q is a divalent silicon-free organic radical which is the residue of an organic
diamine;
and
x is an integer having a value of I4.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (15)
1. A semiconductor element comprising a body of semiconductor material; at least two regions of opposite type conductivity formed in the body; a P-N junction disposed between and formed by the abutting surfaces of each pair of regions of opposite type conductivity; an end portion dfat least one P-N junction exposed at a surface of the body; a layer of a protective coating material disposed directly on the surface of the body and the exposed end portion of at least one P-N junction; the protective coating material being a copolymer material which is a reaction product of a silicon-free organic diamine, an organic tetra carboxylic dianhydride and a polysiloxane diamine which when cured has recurring structural units of the formula:
with from 15 to 40 mol percent intercondensed structural units of the formula:
wherein:
R is a divalent hydrocarbon radical;
R' is a monovalent hydrocarbon radical;
R" is a tetravalent organic radical;
Q is a divalent silicon-free organic radical which is the residue of an organic
diamine;
and
x is an integer having a value of I4.
2. A semiconductor element as claimed in claim I wherein the layer has a
thickness of from I micron to 100 microns.
3. A semiconductor element as claimed in claim 1 or claim 2 wherein the polymeric material is the reaction product of benzophenone tetracarboxylic acid dianhydride with methylene dianiline and bis(aminopropyl)tetramethyl- disiloxane.
4. A semiconductor element as claimed in any one of claims 1 to 3 wherein the semiconductor material is silicon.
5. A semiconductor element as claimed in any one of claims I to 4 wherein the organic tetracarboxylic acid dianhydride is 2,2-bis[4-3,4-dicarboxyphenoxy)phenyl] propane dianhydride or 2;2-bis[4-(2,4-dicarboxyphenoxy)phenyl] propane dianhydride.
6. A semiconductor element as claimed in any one of claims I to 5 wherein the silicon-free organic diamine is 4,4'-diaminodiphenylmethane.
7. A semiconductor element as claimed in any one of claims I to 6 wherein the diamino polysiloxane is 1,3-bis (y-aminopropyl) tetramethyldisiloxane.
8. A modification of the semiconductor element as claimed in any one of the preceding claims wherein the P-N junction is disposed between, and formed by, the abutting surfaces of the material of a pair of regions of opposite type conductivity, extends to a surface of the body and has layer of silicon dioxide is disposed thereon the layer of a protective coating material being disposed on the layer of silicon dioxide.
9. A semiconductor element as claimed in any one of the preceding claims wherein the protective coating is formed from a solution of a polymeric material which on curing comprises a copolymer material which is a reaction product of a silicon-free organic diamine, either 2,2-bis [4-(3,4-dicarboxyphenoxy)phenyl] propane dianhydride or 2,2-bis [4-(2,3-dicarboxyphenoxy)phenyl] propane dianhydride, and a diamino polysiloxane, the reaction product having recurring structural units when cured of the formula:
with from 15 to 40 mol percent intercondensed structural units based on the total numbers of units of the formula:
wherein:
Ris a divalent hydrocarbon radical;
R' is a monovalent hydrocarbon radical;
R" is the tetravalent residue of ether 2,2-bis [4-(3,4-dicarboxyphenoxy)
phenyl] propane dianhydride or 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyll propane dianhydride;
Q is a divalent silicon-free organic radical which is the residue of an organic
diamine;
and
x is an integer having a value of 1 to 4 and a solvent.
10. A semiconductor as claimed in claim 9 wherein the polymeric material -comprises from 10 to 40 percent by weight of the solution.
II. A semiconductor as claimed in claim 9 wherein the percent resinous material in solution is 25.
12. A semiconductor as claimed in any one of claims 9 to I 1 wherein the silicon-free organic diamine is 4,4'-diaminodiphenylmethane.
13. A semiconductor as claimed in any one of claims 9 to 12 wherein the polysiloxane diamine is 1,3-bis (y-aminopropyl tetramethyldisiloxane.
14. A semiconductor element as claimed in claim 1 substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
15. A semiconductor as claimed in claim 9 substantially as hereinbefore described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US65209276A | 1976-01-26 | 1976-01-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1585477A true GB1585477A (en) | 1981-03-04 |
Family
ID=24615479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1219/77A Expired GB1585477A (en) | 1976-01-26 | 1977-01-12 | Semiconductors |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS6047741B2 (en) |
| CH (1) | CH629335A5 (en) |
| DE (1) | DE2702921A1 (en) |
| FR (1) | FR2339252A1 (en) |
| GB (1) | GB1585477A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2162854A (en) * | 1984-08-10 | 1986-02-12 | Gen Electric | High molecular weight siloxane polyimides, intermediates therefor, and methods for their preparation and use |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL59344A (en) * | 1979-03-01 | 1983-06-15 | M & T Chemicals Inc | Precursor solutions of silicone copolymer materials made from a siloxane containing a bis-amino aryl ether or thioether |
| JPS58152018A (en) * | 1982-03-05 | 1983-09-09 | Hitachi Chem Co Ltd | Coating composition for protecting semiconductor device |
| US5094919A (en) * | 1988-06-30 | 1992-03-10 | Nippon Steel Chemical Co., Ltd. | Polyimide copolymers and process for preparing the same |
| JPH03116857A (en) * | 1989-09-29 | 1991-05-17 | Mitsui Petrochem Ind Ltd | Light emitting or photodetective device |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3325450A (en) * | 1965-05-12 | 1967-06-13 | Gen Electric | Polysiloxaneimides and their production |
| GB1230421A (en) * | 1967-09-15 | 1971-05-05 | ||
| US3615913A (en) * | 1968-11-08 | 1971-10-26 | Westinghouse Electric Corp | Polyimide and polyamide-polyimide as a semiconductor surface passivator and protectant coating |
| US3553282A (en) * | 1969-09-08 | 1971-01-05 | Gen Electric | Siloxane containing polyamide acid blends |
| US3597269A (en) * | 1969-09-30 | 1971-08-03 | Westinghouse Electric Corp | Surfce stabilization of semiconductor power devices and article |
| US3740305A (en) * | 1971-10-01 | 1973-06-19 | Gen Electric | Composite materials bonded with siloxane containing polyimides |
| JPS5421073B2 (en) * | 1974-04-15 | 1979-07-27 | ||
| SE418433B (en) * | 1975-12-11 | 1981-05-25 | Gen Electric | SEMICONDUCTOR ELEMENT WITH A LAYER OF A POLYMERIC SILOXAN-CONTAINING MEMBRANE MEMBRANE MATERIAL WITH VARIABLE PERMEABILITY APPLIED ON SELECTED SURFACE OF THE ELEMENT |
| SE418432B (en) * | 1975-12-11 | 1981-05-25 | Gen Electric | SET FOR TREATMENT OF A SELECTED AREA WITH A SEMICONDUCTOR |
| DE2655963C3 (en) * | 1976-12-10 | 1982-03-04 | Agfa-Gevaert Ag, 5090 Leverkusen | Holding device for sheet-shaped and three-dimensional originals on the movable original transport carriage of an optical copier |
-
1977
- 1977-01-12 GB GB1219/77A patent/GB1585477A/en not_active Expired
- 1977-01-25 DE DE19772702921 patent/DE2702921A1/en not_active Withdrawn
- 1977-01-25 FR FR7701973A patent/FR2339252A1/en active Granted
- 1977-01-26 JP JP52006882A patent/JPS6047741B2/en not_active Expired
- 1977-01-26 CH CH95177A patent/CH629335A5/en not_active IP Right Cessation
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2162854A (en) * | 1984-08-10 | 1986-02-12 | Gen Electric | High molecular weight siloxane polyimides, intermediates therefor, and methods for their preparation and use |
| DE3526269A1 (en) * | 1984-08-10 | 1986-03-20 | General Electric Co., Schenectady, N.Y. | HIGH MOLECULAR WEIGHT SILOXANE POLYIMIDES, THEIR INTERMEDIATE PRODUCTS AND METHOD FOR THEIR PRODUCTION AND USE |
| GB2162854B (en) * | 1984-08-10 | 1989-07-26 | Gen Electric | High molecular weight siloxane polyimides, intermediates therefor, and methods for their preparation and use |
| DE3526269C2 (en) * | 1984-08-10 | 2003-06-26 | Microsi Inc | Process for manufacturing an electronic device |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2702921A1 (en) | 1977-09-01 |
| JPS6047741B2 (en) | 1985-10-23 |
| CH629335A5 (en) | 1982-04-15 |
| FR2339252A1 (en) | 1977-08-19 |
| FR2339252B1 (en) | 1982-11-05 |
| JPS52109873A (en) | 1977-09-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PE20 | Patent expired after termination of 20 years |
Effective date: 19970111 |