CN1067805C - Method for connecting semiconductor crystal wafer with transparent conducting thin film - Google Patents

Abstract

The present invention belongs to a method for manufacturing a device in the field of a semiconductor device. A base sheet which comprises a semiconductor element structure is corroded. A base sheet with the same electric conduction performance is additionally used, and is plated with a transparent electric conduction film. A wafer containing the semiconductor element structure is clamped with the base sheet, is arranged in a high temperature furnace, is heated for a period of time, and is combined with the base sheet. The present invention can enhance the luminescence efficiency of diodes, and the present invention can be combined under lower temperature. Simultaneously, a thin layer can become a buffering layer with different lattice constant among the combined wafers, and thus, the structure of crystal combining interfaces is improved. The present invention has good practicality.

Description

Method for connecting semiconductor crystal wafer

The invention belongs to a kind of manufacturing device method in the field of semiconductor devices, refer in particular to the wafer that contains semiconductor element of manufacturing light-emitting diode and the combination technology of substrate.

In the light-emitting diode field, a kind of method that is usually used in improving light-emitting diode luminance is to adopt transparent wafer.Gallium aluminium arsenic (AlGaAs) red light emitting diodes with 660 millimicrons (nm) is an example, and this class light-emitting diode structure roughly can be divided into three kinds.First kind is diode structure as shown in fig. 1, and it contains a GaAs (GaAs) with band conductivity is that the list of substrate 11 is heterogeneous.The single heterojunction structure is a kind of AlGaAs layer 12 with positive conductivity of growth, a kind of AlGaAs layer 13 with negative conductivity of regrowth.The luminosity of this light-emitting diode is 500～800 milli candelas (mcd); Second kind is diode structure as shown in Figure 2, and it comprises AlGaAs bottom 22, the one not doping active A lGaAs middle level 23 with positive conductivity, and is with a negative conductivity AlGaAs upper strata 24, and its substrate is the GaAs layer 21 with positive conductivity.The luminosity of this class light-emitting diode is approximately 1.5 candelas (cd); The third is a diode structure as shown in Figure 3, and it is similar to second kind of structure, and it includes AlGaAs bottom 31, the one not doping active A lGaAs middle level 32 with positive conductivity, and the negative conductivity AlGaAs upper strata 33 of a band.But substrate is then replaced by the AlGaAs substrate 31 with positive conductivity.The luminosity of this light-emitting diode approximately can reach 3 candelas, and it doubles than second kind of light-emitting diode luminance.Its main cause has adopted transparent substrate exactly, and the light that makes light-emitting diode produce can not be absorbed when carrying out toward the transparent substrate direction.In the above-mentioned diode structure, each semiconductor layer all is with the liquid phase deposition growth, though the diode structure among Fig. 3 has best luminous efficiency, the AlGaAs substrate that grow very thick is very difficult.

Light-emitting diode at high efficiency other color gamut of growth, for example from the green glow to the red range, be high-brightness AlGaInP (AlGaInP) light-emitting diode of wavelength at 560 to 630 millimicrons (nm), as shown in Figure 4, this traditional double-heterostructure comprises a kind of (AlGaInP) bottom 43 with negative conductivity, one not doping (AlGaInP) active layer 44, and (AlGaInP) upper strata 45 with positive conductivity.In order to increase wandering from the conductive current of electrode tips 47 and 41, the thick layer 46 of the positive conductivity of one deck band of growing again on the upper strata 45 of double-heterostructure.

In the present AlGaInP diode, generally be with the GaAs of negative conductivity as substrate, yet because the light that major part is sent to substrate all by this lighttight substrate absorption, the luminous efficiency of diode is restricted.The F.A Keyes people such as (F.A.Kish) of California, USA Hewlett-Packard proposes a kind of with GaAs corrosion and transparent and with gallium phosphide (GaP) the substrate combination of the negative conductivity of belt transect with one, replacing former Improvement type diode, wherein employed wafer combination technology is before by breadboard Liao Z.L. of U.S. fiber crops state Lincoln people institute research and developments such as (Z.L.Liau).Though this Improvement type diode has higher luminosity, two shortcomings are arranged, the combination of first wafer must be carried out in quite high temperature, and general about is more than 830 ℃.Another shortcoming is on the faying face of gallium phosphide (GaP) and AlGaInP (AlGaInP), because not matching of lattice constant is easy to cause the crooked of wafer or break.

The objective of the invention is to propose a kind ofly place semiconductor wafer and another to contain between the wafer of semiconductor element with a transparent conducting thin film, as the semiconductor wafer combination technology of bonding agent therebetween, it not only has extraordinary conductivity and light transmission like this, and it can be in order to the resilient coating that combines as different crystal structure between two kinds of different materials, make the crystal combination technology under lower temperature, to carry out, thereby overcome the existing in prior technology problem.

The technical solution adopted in the present invention is, earlier with original substrate in order to the growth double-heterostructure, remove with traditional corrosion technology, be plated on the new transparent substrate with one deck transparent conducting thin film then, double-heterostructure and new substrate being clamped at places high temperature furnace after heating a period of time together again, wafer promptly combines and finishes high efficiency light-emitting diode, and its concrete steps are as follows:

A, prepare the wafer that first contains the GaAs semiconductor element;

B, second printing opacity GaP semiconductor chip of preparation;

Form indium oxide layer tin (ITO)/cadmium tin (CTO) transparent conducting thin film on c, the wafer that contains the GaAs semiconductor element this first or second printing opacity GaP semiconductor chip;

D, again this second printing opacity GaP semiconductor chip and first wafer that contains the GaAs semiconductor element are gripped, said tin indium oxide/indium oxide cadmium transparent conducting thin film is contained between the wafer of GaAs semiconductor element between second printing opacity GaP semiconductor chip and first;

E, the two plates that will grip place about one hour of about 500 ℃～700 ℃ high temperature furnaces heating, can finish the combination of wafer.

Characteristics of the present invention are to have good electrical conductivity and light transmission, simultaneously can be in lower temperature, finish the combination of wafer with the short period, simultaneously owing to after adding one deck transparent conducting thin film, can make wafer avoid diffusion of impurities or superlattice and quantum well structures layer to cause the deterioration of element with the counterdiffusion mutually of interlayer element.The present invention is except easy production, and light transmission film can be used as resilient coating again to adapt to the difference of lattice structure between the different materials.Because film itself is noncrystalline layer also, the different lattice constants of different materials and thermal coefficient of expansion can be cushioned its strain, in conjunction with after wafer more not flexible yet, the present invention can be in conjunction with bigger wafer thus, so it has bigger practicality.

Fig. 1 is a kind of single heterogeneous traditional type light-emitting diode structure sectional drawing of AlGaAs that contains.

Fig. 2 is a kind of traditional type light-emitting diode structure sectional drawing that contains the two heterogeneous and GaAs substrates of AlGaAs.

Fig. 3 is a kind of traditional type light-emitting diode structure sectional drawing that contains the two heterogeneous and AlGaAs substrates of AlGaAs.

Fig. 4 is a kind of light-emitting diode structure sectional drawing that contains AlGaInP pair of heterogeneous and combined GaP substrate.

Fig. 5 is a light-emitting diode structure sectional drawing of the present invention, and it contains an AlGaAs couple of heterogeneous and be coated with one deck ito thin film combined base GaP.

Fig. 6 is combined in 500 ℃ temperature current-voltage characteristic figure through one hour handle after with two GaP substrates with ito thin film for the present invention.

Fig. 7 is combined in 700 ℃ temperature current-voltage characteristic figure through one hour handle after with two GaP substrates with ito thin film for the present invention.

Fig. 8 is a light emitting diode construction sectional drawing of the present invention, the combined base GaP that it comprises an AlGaInP double-heterostructure and is coated with one deck ito thin film.

Further specify a better specific embodiment of the present invention in conjunction with above-mentioned accompanying drawing now.The present invention mainly replaces lighttight substrate with transparent substrate, provides a kind of simple and easy and high efficiency mode of production to make the light-emitting diode of high luminosity.It is the GaP substrate that a slice is coated with negative conductivity type gallium phosphide (GaP) transparent substrate of tin indium oxide (ITO) light transmission film and the negative conductivity type of another sheet, under 500 ℃ temperature, through one hour add thermal and finish.With among Fig. 6 as can be seen the substrate of this combination good current-voltage linear relationship is arranged.Fig. 7 is the I-E characteristic graph of a relation of another kind of combined base.This combined base then is under 700 ℃ temperature, and through one hour add thermal and make, its electric current and voltage also had good linear relationship.Should be noted that in conjunction with the transparent conducting thin film in the interface good light transmittance and conductivity will be arranged, though what the present invention used is the ITO material, other materials with similar characteristics, also have same function as cadmium tin CTO (Cadium-Tin-Oxide) film, utilize this substrate combination technology can improve the brightness of light-emitting diode.

The luminous intensity of the light-emitting diode of manufacturing of the present invention traditional type diode about and among Fig. 3 is identical, but it has avoided the difficulty of the very thick gallium aluminium arsenic AlGaAs substrate of necessary growth.

As shown in Figure 2, double-heterostructure in the tradition light-emitting diode has the substrate with positive conductivity, the gallium aluminium arsenic AlGaAs layer of the positive conductivity of one deck band of on substrate, growing earlier, the not doping active A lGaAs of long again one deck layer on it, the AlGaAs of the negative conductivity of last regrowth one band.

The present invention as shown in Figure 5, the traditional type diode gives erosion removal with the general corrosion choice of technology with its substrate earlier.New substrate is for being the gallium phosphide GaP transparent substrate 51 with positive conductivity equally, substrate surface is plated with the thin ITO transparent conducting thin film 52 of one deck, again it is gripped with the double-heterostructure of removing substrate and be placed in the high temperature furnace that is connected with nitrogen or hydrogen, heating is about one hour under about 500 ℃ temperature, can finish the combination of wafer.Therefore structure of the present invention includes with AlGaAs bottom 53, the not doping active A lGaAs middle level 54 of the thin ITO transparency conducting film 52, of the GaP transparent substrate 51, of positive conductivity with positive conductivity, and the negative conductivity AlGaAs upper strata 55 of a band.

Another enforcement of the present invention is the traditional type diode that contains AlGaInP that also can be used to produce as shown in Figure 4; To bear the GaP substrate replacement combination of conductivity again with the band that is coated with ito thin film, to finish diode as shown in Figure 8 with the GaAs substrate erosion removal of negative conductivity earlier.Though two heterogeneous material differences, same combination technology still can use.In the structure of Fig. 8, from bottom to top include AlGaInP bottom 84, one not doping AlGaInP active layer 85, an AlGaInP upper strata 86 and thick layer 87 and another electrode tips 88 with positive conductivity with positive conductivity of electrode tips 81, the negative conductivity GaP substrate 82 of a band, an ITO transparency conducting film that approaches 83, the negative conductivity of a band.

Claims (1)

1, a kind of method for connecting semiconductor crystal wafer is characterized in that including following steps:

C, prepare the wafer that first contains the GaAs semiconductor element;

D, second printing opacity GaP semiconductor chip of preparation;

Form indium oxide layer tin (ITO)/cadmium tin (CTO) transparent conducting thin film on c, the wafer that contains the GaAs semiconductor element this first or second printing opacity GaP semiconductor chip;

D, again this second printing opacity GaP semiconductor chip and first wafer that contains the GaAs semiconductor element are gripped, said tin indium oxide/indium oxide cadmium transparent conducting thin film is contained between the wafer of GaAs semiconductor element between second printing opacity GaP semiconductor chip and first;

E, the two plates that will grip place about one hour of about 500 ℃～700 ℃ high temperature furnaces heating, can finish the combination of wafer.

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