CN100392929C - Semiconductor device and method for fabrication thereof - Google Patents

Semiconductor device and method for fabrication thereof Download PDF

Info

Publication number
CN100392929C
CN100392929C CNB2005100701801A CN200510070180A CN100392929C CN 100392929 C CN100392929 C CN 100392929C CN B2005100701801 A CNB2005100701801 A CN B2005100701801A CN 200510070180 A CN200510070180 A CN 200510070180A CN 100392929 C CN100392929 C CN 100392929C
Authority
CN
China
Prior art keywords
nitride semiconductor
cutting zone
nitride
substrate
layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CNB2005100701801A
Other languages
Chinese (zh)
Other versions
CN1697273A (en
Inventor
神川刚
山田英司
荒木正浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Fukuyama Laser Co Ltd
Original Assignee
Sharp Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sharp Corp filed Critical Sharp Corp
Publication of CN1697273A publication Critical patent/CN1697273A/en
Application granted granted Critical
Publication of CN100392929C publication Critical patent/CN100392929C/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Semiconductor Lasers (AREA)
  • Led Devices (AREA)
  • Chemical Vapour Deposition (AREA)

Abstract

On a processed substrate having an engraved region as a depressed portion formed thereon, a nitride semiconductor thin film is laid. The sectional area occupied by the nitride semiconductor thin film filling the depressed portion is 0.8 times the sectional area of the depressed portion or less.

Description

Semiconductor device and manufacture method thereof
Technical field
The present invention relates to a kind of semiconductor device such as nitride semiconductor laser device, and the method for making this semiconductor device.
Background technology
Compare with the AlGaInP base semiconductor with AlGaInAs base, such as the nitride-based semiconductor of GaN, AlGaN, GaInN, AlGaInN, and mixed crystal has the bigger characteristics of band gap Eg, and is the direct-gap seminconductor material.For light emitting semiconductor device, for example to the semiconductor laser of the short wavelength range of green glow and the light-emitting diode of the wide emission wavelength scope of covering from the ultraviolet ray to ruddiness, these attributes make nitride-based semiconductor become attractive material to light emitting region in ultraviolet ray.Therefore, it is believed that nitride-based semiconductor will use to obtaining aspect environment and the medical field widely at high density compact disc and full-color display.
And nitride-based semiconductor has higher conductive coefficient than GaAs base semiconductor and other semiconductors, therefore estimates will obtain extensive use aspect high temperature, the high-output power device.In addition, nitride-based semiconductor do not require use with the AlGaAs base semiconductor in arsenic (As), the corresponding material of cadmium in the ZnCdSSe base semiconductor, or be used for they such as arsine (AsH 3) raw material, therefore expection belongs to the environmental protection compound semiconductor materials.
For nitride-based semiconductor, a traditional problem is: be example with the nitride semiconductor laser device, in the process of making nitride compound semiconductor device, rate of finished products, be the ratio of quantity and the device total amount of on single wafer, producing of the nitride semiconductor laser device of operate as normal, extremely low.
Reason is as described below.For each nitride semiconductor laser device that will make on the same wafer is separated from each other, at first, with wafer along direction cleavage perpendicular to the resonant cavity of nitride semiconductor laser device, thereby described wafer is divided into rectangular, the end face of resonant cavity is formed at the cleaved surface place.Next, for further will be now altogether each nitride semiconductor laser device on the strip separation member of the mutual cleavage of nitride-based semiconductor substrate separate, will along the further splitting of direction that is parallel to resonant cavity generated rectangular.Here, wafer is being divided into when rectangular, if the nitride-based semiconductor substrate is to be made of the nitride-based semiconductor such as n type GaN, nitride-based semiconductor substrate and position nitride semiconductor growing layer thereon have cleavage surface in the direction perpendicular to resonant cavity so, therefore are easy to cleavage.
But, because the nitride-based semiconductor substrate that is made of the nitride-based semiconductor such as n type GaN has hexagonal crystallographic texture, do not have cleavage surface in the direction that is parallel to the resonant cavity direction, therefore, be difficult to the described rectangular independently nitride semiconductor laser device that further is divided into.Therefore, the fractionation here can cause peeling off and rupturing, and along unexpected direction cleavage, these can cause low rate of finished products.
According to the traditional solution that provides at this problem, after the nitride semiconductor growing layer has covered substrate top, adopt scribing machine half cutting to substrate thickness from the surface of nitride semiconductor growing layer, the substrate of polishing afterwards makes it attenuation, next, on the flute surfaces of utilizing scribing machine to form, draw line, last, on substrate, apply a load.This helps with good rate of finished products each nitride semiconductor laser device separated from one another (referring to Japanese Patent Application Laid-Open No.H5-315646).
The Another reason of low rate of finished products is the generation of crackle.This type of crackle may originate from the nitride semiconductor growing layer that covers substrate top.Particularly, when making nitride semiconductor laser device, cover the nitride semiconductor growing layer, and this nitride semiconductor growing layer is made up of dissimilar films, for example GaN, AlGaN and InGaN film in substrate top.Here, the different films that form the nitride semiconductor growing layer have different lattice constants, thereby cause lattice mismatch, cause the generation of crackle.For fear of this situation,, adopt a kind of substrate after treatment according to a kind of traditional recommend method, and, after the nitride semiconductor growing layer is formed on its top, on the surface of nitride semiconductor growing layer, form depression, rather than planarization is carried out on the surface.This helps to reduce crackle (referring to Japanese Patent Application Laid-Open No.2002-246698).By adopting this method, for example might reduce by being formed at substrate top and constitute the crackle that the lattice constant mismatch between each film of nitride semiconductor growing layer causes.
When disclosed technology is made nitride semiconductor laser device in adopting above-mentioned Japanese Patent Application Laid-Open No.2002-246698 (Japanese Patent Application Publication No.2002-246698), as an example, the structure of nitride semiconductor growing layer can be as shown in figure 19.
Specifically, by form through overetched n type GaN substrate or similar material, handle on the surface of substrate 10 (referring to Figure 18 a and 18b), form nitride semiconductor growing layer 11, for example, nitride semiconductor growing layer 11 is by constituting according to stacked following each layer of specified order: the n type GaN layer 100 that 1.0 μ m are thick; 1.5 the n type Al that μ m is thick 0.062Ga 0.938N first coating (clad layer) 101; 0.2 the n type Al that μ m is thick 0.1Ga 0.9N second coating 102; 0.1 the n type Al that μ m is thick 0.062Ga 0.938N the 3rd coating 103; 0.1 the n type GaN ducting layer 104 that μ m is thick; By three InGaN trap layer and four multiple quantum well active layer 105 that the thick GaN barrier layer of 8nm constitutes that 4nm is thick; The p type Al that 20nm is thick 0.3Ga 0.7N vaporization prevention layer (evaporation prevention layer) 106; 0.05 the p type GaN ducting layer 107 that μ m is thick; 0.5 the p type Al that μ m is thick 0.062Ga 0.938N coating 108; And the thick p type GaN contact layer 109 of 0.1 μ m.Multiple quantum well active layer 105 has stacked in the following order layer: barrier layer, trap layer, barrier layer, trap layer, barrier layer, trap layer and barrier layer.
In crystallography, convention is: when the index in indication one crystal face or crystal orientation is negative, adds a horizontal line and represent this index on its absolute value.In following explanation owing to can't adopt this index, shown in adopt minus sign "-" expression negative exponent, its heel is stated the absolute value of index to some extent.
In this manual, the substrate substrate in addition that forms by nitride-based semiconductor of " different substrate " expression.The example of different substrates comprises: Sapphire Substrate, SiC substrate and GaAs substrate.
Expression has the substrate of cutting zone and oncus " to have handled substrate ", and this cutting is regional to be formed on the surface of nitride-based semiconductor substrate or on the surface of nitride semiconductor thin film stacked on the surface of nitride-based semiconductor substrate or different substrates with oncus.In following explanation, the stacked Mg layer of mixing, i.e. p type Al in order 0.3Ga 0.7N vaporization prevention layer 106, p type GaN ducting layer 107, p type Al 0.062Ga 0.938 N coating 108 and p type GaN contact layer 109 and the layer that forms is called " p layer ".
Handling on the treatment surface of substrate 10, by the stacked nitride semiconductor growing layer 11 of MOCVD (metal organic chemical vapor deposition), to have the nitride semiconductor wafer of depression on the surface that is formed on nitride semiconductor growing layer 11, shown in Figure 18 a and 18b.In Figure 18 a and 18b, unified expression planar orientation.
In Figure 18 b, adopt n type GaN substrate as substrate 10, and form striated cutting zone 16 and oncus 19 along [1-100] direction by dry etching such as RIE (reactive ion etching).The cutting zone is that 5 μ m are wide, and 3 μ m are dark, and the distance between two adjacent cutting zones is 15 μ m.At top, make structure nitride semiconductor growing layer 11 as shown in figure 19 by growing method such as MOCVD through etched substrate 10 like this.
But, disappointedly be, in adopting as Japanese Patent Application Laid-Open No.2002-246698 disclosed technology, with n type GaN substrate as substrate 10, when epitaxial growth nitride semiconductor growing layer 11 is made nitride semiconductor laser device on this n type GaN substrate by MOCVD or similar method, really crackle can be reduced, but rate of finished products can't be significantly improved.Specifically, by having made a plurality of nitride semiconductor laser devices as the disclosed technology of Japanese Patent Application Laid-Open No.2002-246698, therefrom randomly draw 100, measure its FFP (far field pattern along level and vertical direction, the far field pattern) FWHM (full widths athalf maximum, half maximum overall with).Here, think the FFP that shown FWHM its design load ± nitride semiconductor laser device in 1 ° the scope is an acceptable.As a result, the number that the FWHM of the FFP that is shown meets the requirements of nitride semiconductor laser device is 30, and rate of finished products is very low.
This is because stay the evenness that depression has reduced film on nitride semiconductor growing layer 11.The evenness that reduces causes each layer thickness in the nitride semiconductor growing layer 11 to change, thereby causes the characteristic of nitride semiconductor laser device to change along with the difference of individuality, and then has reduced characteristic and dropped on the interior device count of claimed range.Therefore, want to improve rate of finished products, not only will reduce crackle, also will improve the evenness of film.
In addition, also to measuring as the surface smoothness in the nitride semiconductor wafer surface of Figure 18 a, 18b and formation shown in Figure 19.The surface evenness measuring result that edge [1-100] direction obtains as shown in figure 20.The condition of measuring is as follows: measure length: 600 μ m; Measuring Time: 3s; Probe pressure: 30mg; And horizontal resolution: 1 μ m/ sample.On the curve from Figure 20, can find that in the wide zone of 600 μ m, measured the highest part in surface and the height difference between the lowermost portion are 200nm.
Shown in Figure 18 b, the reason of this poor flatness is: each layer thickness that is arranged in the nitride semiconductor growing layer 11 at substrate 10 tops changes along with the difference of the position on the wafer.Therefore, according to the position difference of making nitride semiconductor laser device on the wafer surface, the characteristic of nitride semiconductor laser device will take place to change greatly, and, its thickness to the characteristic of nitride semiconductor laser device have very big influence the thickness of mixing Mg p layer (corresponding to as shown in figure 19 from p type Al 0.3Ga 0.7The summation of the p type layer that N vaporization prevention layer 106 is arranged to p type GaN contact layer 109) difference along with the position in substrate surface changes greatly.
After the oncus structure that forms as current confinement structure, keep the oncus that is the wide striated of 2 μ m, and adopt ICP (inductively coupled plasma, inductively coupled plasma) equipment or similar devices, remove remainder by the dry etch technique etching.Therefore, if before etching, the p layer thickness changes with the difference of position in the wafer surface, and so after etching, the thickness that the properties influence of nitride semiconductor laser device is remained the most significantly the p layer will change along with the difference of position in the wafer surface.As a result, not only the layer thickness of nitride semiconductor laser device changes along with the difference of individuality, even in the middle of same nitride semiconductor laser device, the residue p layer thickness at some position can be almost nil, and is then quite big in other parts.The difference in thickness of residue p layer affects the Laser emission life-span of nitride semiconductor laser device, and aforesaid, such as the characteristic of the FWHM of FFP.
The big distribution of layer thickness in wafer surface is considered to be caused by following reason: comprising the speed of growth of handling the film that the oncus place on the substrate obtains by epitaxial growth of nitride-based semiconductor substrate, under the influence in cutting zone, to change, thereby cause growth rate inequality in the wafer surface.
Specifically, shown in Figure 21 a, from substrate 10 beginning epitaxial growths the time with cutting zone 16 formed thereon, in the initial period of growth, partly be called cutting region growing part 122 with growing in the bottom surface portions 124 in cutting zone 16 and the nitride semiconductor thin film of lateral parts 126, described cutting growth part 122 has only carried out partially filled to cutting zone 16.In this stage, the part of nitride semiconductor thin film on surface that grows in the summit portion 123 of oncus 19 is called grown on top part 121, when it was grown, it is smooth that the surface of nitride semiconductor thin film keeps.
The epitaxial growth of nitride semiconductor thin film enters stage shown in Figure 21 b from the above-mentioned stage shown in Figure 21 a after, cutting region growing part 122, promptly grow in the part of the nitride semiconductor thin film of the bottom surface portions 124 in cutting zone 16 and lateral parts 126, almost thoroughly filled cutting zone 16, at this moment, these parts are connected to grown on top part 121 by growth part 125, promptly grow in the lip-deep nitride semiconductor thin film part of the summit portion 123 of oncus 19.In this stage, make the raw material atom on the nitride semiconductor thin film surface that is attached to the summit portion 123 that is grown in oncus 19 and molecule (for example Ga atom) move or move in growth part 125 and the cutting region growing part 122 by means of heat energy.In wafer surface, the travel motion of this atom and molecule takes place very inhomogeneously, and migration distance does not wait yet in wafer surface.As a result, shown in Figure 21 b, reduced the surface flatness of grown on top part 121.
Distribute such as wafer surface inner bevel (off-angle) and wafer surface under the influence of nitride-based semiconductor substrate self inhomogeneities of substrate curvature distribution, under the influence of the inhomogeneities of the interior epitaxial growth speed of substrate surface, under the influence of the inhomogeneities of cutting technology and other factors, nitride semiconductor thin film also has been lowered along the flatness of [1-100] direction in the substrate surface.Specifically, on [1-100] direction, filling up the cutting 16 required times of zone does not wait, therefore, in the position of early filling up, the raw-material atom of formation nitride semiconductor thin film and molecule move or move in the middle of growth part 125 or the cutting region growing part 122 from the grown on top part 121 of oncus 19.Therefore, where are those atoms and molecular migration, where just need more time to form nitride semiconductor thin film, thereby cause the nitride semiconductor thin film thickening of formation in cutting zone 16.On the other hand, in the position of thoroughly not filling cutting zone 16, move to cutting zone 16 from the grown on top part 121 of oncus 19 without any the raw material atom that forms nitride semiconductor thin film or molecule; Even there be this moving, also only need less time to form nitride semiconductor thin film.Therefore, the nitride semiconductor thin film that forms in cutting zone 16 is thinner than the nitride semiconductor thin film of the more Zao position of filling up cutting zone 16.
In so-called supply state of a control, it is the state that growth rate is subjected to offering controls such as the atom of wafer surface and molecular flux, if form the raw-material atom and the molecular migration of nitride semiconductor thin film or flow in the middle of the cutting zone 16, because offering the raw material atom and the molecular flux on entire wafer surface fixes, so on the summit portion 123 of oncus 19 growth nitride semiconductor thin film, promptly grown on top part 121 is with attenuation.Otherwise, promptly, if flow in other words in the cutting zone 16 without any the raw material atom or the molecular migration that form nitride semiconductor thin film, the nitride semiconductor thin film of growth on the summit portion 123 of oncus 19 so, promptly grown on top part 121 is with thickening.
As a result, the thickness that is positioned at the grown on top part 121 on the summit portion 123 of oncus 19 changes at wafer plane, thereby has reduced the surface flatness of nitride semiconductor thin film.Therefore, want to improve flatness, must suppress to form the raw material atom of nitride semiconductor thin film and molecule from grown on top part 121 migrations of oncus 19 or move to growth part 125 or cutting region growing part 122 and form nitride semiconductor thin film.
And, have been found that, when disclosed above-mentioned technology is made semiconductor laser device in passing through Japanese Patent Application Laid-Open No.2002-246698, if in nitride semiconductor growing layer 11 lip-deep depression, form electrode, in depression, the electric current leakage path will be produced, therefore normal I-V characteristic can't be obtained.Usually, on depression, form such as SiO 2Dielectric film, form electrode more thereon.But it is inhomogeneous that existing here depression causes being formed at the dielectric film on surface, thereby leave over a large amount of fine cracks, extremely thin zone and aperture (hole) etc.Therefore, electric current leaks by the non-homogeneous part of formed dielectric film.
On the other hand, also find, disclosed above-mentioned technology is manufactured on each nitride semiconductor laser device on the nitride-based semiconductor substrate when separated from one another in will be by Japanese Patent Application Laid-Open No.H5-315646, owing to be after the intact nitride semiconductor growing layer of the stacked on top of nitride-based semiconductor substrate, just to form groove by scribing machine, therefore, may damage the nitride semiconductor growing layer internally, thus deterioration the characteristic of nitride semiconductor laser device.
Summary of the invention
In view of the problem that runs into usually discussed above, one object of the present invention is to provide a kind of semiconductor device and manufacture method thereof, wherein, when arranging the semiconductor device of method manufacturing such as nitride semiconductor laser device of nitride semiconductor growing layer on by the substrate that on its surperficial at least a portion, has nitride semiconductor layer, prevented the generation of crackle, and, by suppressing partly to move or move to from the lip-deep grown on top of oncus the method that forms of the regional nitride semiconductor thin film that causes of cutting by raw material atom that forms nitride semiconductor thin film and molecule, formed nitride semiconductor growing layer, thereby eliminated electric current leakage path and damage with excellent surface flatness.
Want to realize above-mentioned purpose, according to the present invention, the method of making nitride compound semiconductor device comprises: first step, on at least a portion surface is on the nitride-based semiconductor substrate of nitride-based semiconductor, or by arranging on such nitride-based semiconductor substrate on the substrate that nitride semiconductor thin film forms, formation has been handled substrate as the cutting of at least one sunk part zone with as the spine portion in non-cutting zone thereby form; With second step, the nitride semiconductor layer part that layout is made of a plurality of nitride semiconductor thin films on the surface that is formed at the cutting zone of handling on the substrate and spine portion.Here, in first and second steps, the area of section that will begin to be parallel to the plane institute region surrounded of the surface of spine portion extending along the sunk part that cuts perpendicular to the plane of the bearing of trend of sunk part with from the surface of spine portion is made as A, the area of section that nitride semiconductor thin film covered that is arranged in the sunk part is made as B, and the B/A that represents the filling ratio of nitride semiconductor thin film in the sunk part so is 0.8 or lower.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in first step, the sunk part in formed cutting zone has the A/F that surpasses 100 μ m, in second step, the gross thickness from the spine portion surface to the nitride semiconductor layer part surface is 0.8 times of the sunk part degree of depth or lower.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in first step, the sunk part in formed cutting zone has the A/F that surpasses 30 μ m but be less than or equal to 100 μ m, and in second step, the gross thickness from the spine portion surface to the nitride semiconductor layer part surface is 2 times of the sunk part degree of depth or lower.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in first step, the sunk part in formed cutting zone has more than or equal to 2 μ m, A/F smaller or equal to 30 μ m, and in second step, the gross thickness from the spine portion surface to the nitride semiconductor layer part surface is 3 times of the sunk part degree of depth or lower.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that this method further comprises: third step, form electrode pad being arranged in to handle on nitride semiconductor layer substrate surface, that be formed at second step part, at the enterprising line lead bonding of electrode pad, thereby realize outside the connection, and then on substrate, form a plurality of nitride compound semiconductor devices.Here, in third step, on the cutting zone, do not form electrode pad.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in third step, apart from the edge 5 μ m in cutting zone or form electrode pad more than the 5 μ m.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in first step, and spine portion has more than or equal to 92 μ m, smaller or equal to the width of 4mm.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion forms a nitride compound semiconductor device in being clipped in two spine portion between the adjacent cutting zone, or a plurality of nitride compound semiconductor device.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is carried out scribing on bottom that is positioned at the nitride-based semiconductor substrate part under the cutting zone of handling substrate just or end face, thereby realizes that chip separates.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that this method further comprises: the 4th step, the bearing of trend in the cutting zone of nitride compound semiconductor device is a first direction, substrate has been handled in splitting on perpendicular to the direction of described first direction, has the rectangular of a plurality of nitride compound semiconductor devices thereon to form each; With the 5th step, cut apart rectangularly on the direction of first direction being parallel to, each nitride compound semiconductor device on rectangular is divided into independently chip, thereby realizes that chip separates.Here, in the 5th step, thereby carry out on the end face that is arranged in the nitride semiconductor layer part on the cutting zone or on the bottom surface of the part of the nitride-based semiconductor substrate under being positioned at the cutting zone just scribing handle form be parallel to the line of first direction after, carry out chip and separate.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that described method comprises the described the 4th and the 5th step, and, in the 5th step, on the end face that is arranged in the nitride semiconductor layer part on the cutting zone or be positioned at just on the bottom surface of the nitride-based semiconductor substrate part under the cutting zone, and on the end face that is arranged in the nitride semiconductor layer part on the spine portion or be positioned at just and carry out scribing on the bottom surface of the nitride-based semiconductor substrate part under the spine portion and handle, thereby realize that chip separates.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that described method comprises the 4th and the 5th step, and, in the 5th step, form line with form from the solid line of each rectangular end to end.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that described method comprises the 4th and the 5th step, and, in the 5th step, on each rectangular part, form the line of solid line shape.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that described method comprises the 4th and the 5th step, and, in the 5th step, form line with form from the dotted line of each rectangular end to end.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that described method comprises the 4th and the 5th step, and, in the 5th step, in the marginal portion, form line at the edge that on direction, forms perpendicular to first direction.
According to the present invention, by a kind of making nitride compound semiconductor device in the method for above-mentioned manufacturing nitride compound semiconductor device.
Alternatively, according to the present invention, the method of making semiconductor device comprises: first step, in its at least a portion surface, have and form cutting zone that forms as at least one sunk part and the spine portion that forms as non-cutting zone on the substrate of nitride semiconductor layer, form with this and handle substrate.Here, described method further comprises: second step, and the inflow that forms as raised portion along two edges that are formed at the spine portion of handling on the substrate prevents wall; And third step, handle on the substrate, have on the surface that the inflow that is formed at second step prevents the cutting zone of wall and spine portion and form the nitride semiconductor layer part that comprises at least a nitride semiconductor thin film being formed at, thereby the inflow that forms on the both sides along spine portion prevents to form on the wall nitride semiconductor layer part, the inflow that form to raise thus prevents part, thereby has a difference in height with the surface of the flat of the lip-deep nitride semiconductor layer part that is arranged in spine portion.
In the method for above-mentioned manufacturing nitride compound semiconductor device, when suggestion forms the nitride semiconductor layer part in third step, thoroughly do not fill sunk part as the cutting zone.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in second step, by SiO 2, Al 2O 3, TiO 2, a kind of formation among ZrO and the W flows into and prevents wall.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion forms in second step and flows into when preventing wall, make to flow into to prevent wall perpendicular to self, and have more than or equal to 50nm on the direction perpendicular to the surface of spine portion thus, smaller or equal to the thickness of 3 μ m.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion forms in second step and flows into when preventing wall, makes to flow into to prevent that wall has more than or equal to 1 μ m, smaller or equal to the width of 25 μ m on the direction that prevents the wall length direction perpendicular to inflow.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that this method further comprises: the 4th step, handle substrate surface being arranged in, have the inflow that is formed at third step and prevent that the nitride semiconductor layer of wall from partly upward forming electrode pad, at the enterprising line lead bonding of electrode pad, thereby realize outside the connection, and then on substrate, form a plurality of semiconductor device.Here, in the 4th step, on the cutting zone, do not form electrode pad.
Alternatively, according to the present invention, the method of making semiconductor device comprises: first step, in at least a portion surface, have and form cutting zone that forms as at least one sunk part and the spine portion that forms as non-cutting zone on the substrate of nitride semiconductor layer, form with this and handle substrate; With second step, the nitride semiconductor layer part that formation is made of a kind of nitride semiconductor thin film at least on the surface that is formed at the cutting zone of handling on the substrate and spine portion.Here, in second step, make and be arranged near the thickness of the part of the nitride semiconductor layer on two marginal portions of the spine portion in cutting zone thickness greater than the nitride semiconductor layer part of beyond two edges of spine portion, arranging, last thickness is to record from the surface of spine portion to the surface of nitride semiconductor layer part, back one thickness also is to record from the surface of spine portion to the surface of nitride semiconductor layer part, prevents part thereby form from the inflow of the surface rising of the planar section of the nitride semiconductor layer part that is arranged in the region surface except that two marginal portions of spine portion.
In the method for above-mentioned manufacturing nitride compound semiconductor device, when suggestion forms the nitride semiconductor layer part in second step, thoroughly do not fill sunk part as the cutting zone.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in second step, and the height difference between the inflow that surface and the surface from described flat of the flat of the nitride semiconductor layer part that is arranged in the spine portion surface are raise prevents partly is 150nm or bigger.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is the GaN of thickness smaller or equal to 0.5 μ m with handling the nitride semiconductor thin film that substrate surface directly contacts in second step.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is AlGaN with handling the nitride semiconductor thin film that substrate surface directly contacts in second step.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is GaN with handling the nitride semiconductor thin film that substrate surface directly contacts in second step, and, GaN is being arranged in when handling substrate surface, the temperature of having handled substrate surface is 1025 ℃.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in second step, with handling the nitride semiconductor thin film that substrate surface directly contacts is GaN, and, when arranging GaN, the unit interval provides and comprises nitrogen-atoms and provide as the raw-material mole flow velocity of V group element and unit interval that to comprise the gallium atom be 2000 or higher as the ratio between the raw-material mole of flow velocity of III family element.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in second step, and the nitride semiconductor thin film that forms the nitride semiconductor layer part comprises that Al content is 0.02 AlGaN layer.
In the method for above-mentioned manufacturing nitride compound semiconductor device, advise that this method further comprises: the 4th step, handle substrate surface being arranged in, the nitride semiconductor layer that is formed at second step is partly gone up the formation electrode pad, at the enterprising line lead bonding of electrode pad, thereby realize outside the connection, and then on substrate, form a plurality of semiconductor device.Here, in the 4th step, on the cutting zone, do not form electrode pad.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is in the 4th step, apart from the edge 30 μ m in cutting zone or form electrode pad more than the 30 μ m.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion forms a nitride compound semiconductor device in being clipped in two spine portion between the adjacent cutting zone, or a plurality of nitride compound semiconductor device.
In the method for above-mentioned manufacturing nitride compound semiconductor device, suggestion is on the end face that is arranged in the nitride semiconductor layer part on the cutting zone or be positioned at just and carry out scribing on the bottom surface that handling the substrate part under the cutting zone and handle, thereby realizes that chip separates.
In the method for above-mentioned manufacturing nitride compound semiconductor device, when suggestion forms as the cutting zone of sunk part in first step, sunk part is had more than or equal to 1 μ m, smaller or equal to the degree of depth of 20 μ m.
In the method for above-mentioned manufacturing nitride compound semiconductor device, when suggestion forms as the cutting zone of sunk part in first step, make sunk part have A/F more than or equal to 1 μ m.
Utilize in the said method any, may prevent that all the cutting zone from being filled up by nitride semiconductor thin film and may prevent that the different piece of nitride semiconductor thin film from meeting on the cutting zone, and form the cavity.
In the method for above-mentioned manufacturing nitride compound semiconductor device, when suggestion forms as the cutting zone of sunk part in first step, make to be clipped in two spine portion between the adjacent cutting zone and to have more than or equal to 140 μ m, smaller or equal to the width of 4mm.
According to the present invention, a kind of making semiconductor device of the method by above-mentioned manufacturing semiconductor device.
Description of drawings
Fig. 1 a is the schematic cross section of the nitride semiconductor laser device of first embodiment of the invention;
Fig. 1 b is the schematic top view of the nitride semiconductor laser device of the first embodiment of the present invention;
Fig. 2 a is the schematic cross section of handling substrate with cutting zone with rectangle cross sectional shape formed thereon;
Fig. 2 b is the schematic cross section of handling substrate with cutting zone with triangle and trapezoidal sectional shape formed thereon;
Fig. 3 a is the schematic top view of handling substrate of the first embodiment of the present invention;
Fig. 3 b is the schematic cross section of handling substrate of the first embodiment of the present invention;
Fig. 4 a is in the first embodiment of the present invention, in the starting stage of nitride semiconductor thin film growth, has handled the schematic cross section of substrate;
Fig. 4 b is in the first embodiment of the present invention, in the later stage of nitride semiconductor thin film growth, has handled the schematic cross section of substrate;
Fig. 5 is the graph of a relation between the average deviation σ of compactedness C and p layer thickness in the first embodiment of the present invention;
Fig. 6 a is in the first embodiment of the present invention, under the state of cutting zone by the nitride semiconductor thin film filling, has handled the schematic cross section of substrate;
Fig. 6 b is in the first embodiment of the present invention, under the state of cutting zone by the nitride semiconductor thin film filling, has handled the schematic cross section of substrate;
Fig. 6 c is in the first embodiment of the present invention, forms under the state in the cavity that is centered on by nitride semiconductor thin film in the cutting zone, has handled the schematic cross section of substrate;
Fig. 7 a is in the first embodiment of the present invention, divides the partial schematic top view of nitride-based semiconductor substrate into strips;
Fig. 7 b is in the first embodiment of the present invention, divides the partial schematic cross-sectional view of nitride-based semiconductor substrate into strips;
Fig. 8 a is in the first embodiment of the present invention, and the schematic top view of the chip separation point position on the nitride semiconductor laser device is described;
Fig. 8 b is in the first embodiment of the present invention, and the schematic cross section of the chip separation point position on the nitride semiconductor laser device is described;
Fig. 9 is in the first embodiment of the present invention, is divided into the schematic cross section of the nitride semiconductor laser device of separate chip;
Figure 10 a is in another example of the first embodiment of the present invention, and the schematic top view of the chip separation point position on the nitride semiconductor laser device is described;
Figure 10 b is in another example of the first embodiment of the present invention, and the schematic cross section of the chip separation point position on the nitride semiconductor laser device is described;
Figure 11 a is the schematic cross section of the nitride semiconductor laser device of second embodiment of the invention;
Figure 11 b is the schematic top view of the nitride semiconductor laser device of second embodiment of the invention;
Figure 12 a is the schematic top view of handling substrate of the second embodiment of the present invention;
Figure 12 b is the schematic cross section of handling substrate of the second embodiment of the present invention;
Figure 13 is in the second embodiment of the present invention, has the schematic cross section at a part of wafer of handling the nitride semiconductor thin film of growing on the substrate;
Figure 14 a is in the second embodiment of the present invention, under the state of cutting zone by the nitride semiconductor thin film filling, has handled the schematic cross section of substrate;
Figure 14 b is in the second embodiment of the present invention, forms under the state in the cavity that is centered on by nitride semiconductor thin film in the cutting zone, has handled the schematic cross section of substrate;
Figure 15 a is in the second embodiment of the present invention, divides the partial schematic top view of nitride-based semiconductor substrate into strips;
Figure 15 b is in the second embodiment of the present invention, divides the partial schematic cross-sectional view of nitride-based semiconductor substrate into strips;
Figure 16 is in the third embodiment of the present invention, has the partial schematic cross-sectional view at the wafer of handling the nitride semiconductor thin film of growing on the substrate;
Figure 17 is the graph of a relation between height difference H and the acceptable device count;
Figure 18 a is the schematic top view with the conventional wafer that is arranged in the nitride semiconductor growing layer of handling substrate top;
Figure 18 b is the schematic cross section with the conventional wafer that is arranged in the nitride semiconductor growing layer of handling substrate top;
Figure 19 is the schematic cross section of nitride semiconductor growing layer;
Figure 20 is the schema mapping with the surface height difference on the conventional wafer that is arranged in the nitride semiconductor growing layer of handling substrate top;
Figure 21 a is in the starting stage of nitride semiconductor thin film growth, the conventional schematic cross section of handling substrate; And
Figure 21 b is the later stage in the nitride semiconductor thin film growth, the conventional schematic cross section of handling substrate.
Embodiment
At first, will be to what use in this specification, some terms of expressing key principle define." cutting zone " is illustrated in the striated sunk part that forms on the surface of nitride-based semiconductor substrate or different substrates, similar with shown in Fig. 2 a and Fig. 2 b.Fig. 2 a and Fig. 2 b handle through cutting, thereby have formed the schematic cross section of the substrate of cutting zone 16 and oncus 19 thereon.The cross sectional shape in this type of cutting zone 16 may not be a rectangle, can also be triangle shown in Fig. 2 b or trapezoidal; That is to say only needs moulding is carried out in cutting zone 16, makes that producing difference in height between sunk part and raised portion gets final product.May not assign to form each cutting zone 16 with single depressed part, as described in follow-up explanation, each cutting zone 16 can be made up of a plurality of sunk parts and the narrow flat that is clipped in therebetween.
Similarly, the formed banded raised portion of " oncus " expression.In Fig. 2 a and Fig. 2 b, cutting zone 16 and oncus 19 are to form according to the striated pattern that extends along a direction.Also can form cutting zone 16 or oncus 19 according to the lattice that extends along cross one another different directions.On single substrate, formed cutting zone 16 can have different shapes, the different degree of depth or different width.Interval that can be different on single substrate forms cutting zone 16.
" nitride-based semiconductor substrate " expression is by Al xGa yIn zThe substrate that N (0≤x≤1,0≤y≤1,0≤z≤1, and x+y+z=1) constitutes.Here, in the nitrogen element that the nitride-based semiconductor substrate contains, there is the nitrogen element below 10% or 10% can be approximately by As, P or Sb element substitution (condition is that substrate keeps hexagonal crystallographic texture).And Si, O, Cl, S, C, Ge, Zn, Cd, Mg or Be can mix in the nitride-based semiconductor substrate.In these dopant materials, Si, O and Cl are particularly suited for n type nitride-based semiconductor.Be suitable for use as the nitride-based semiconductor substrate the primary flat direction be C plane { 0011}, A plane { 11-20}, R plane { 1-102}, M plane { 1-100} or { 1-101} plane.As long as the substrate primary flat departs from the angle of any one direction in those crystal planes and is less than or equal to 2 °, its configuration of surface just can be satisfactory.
First embodiment
Now, with reference to relevant drawings the first embodiment of the present invention is illustrated.Present embodiment relates to the nitride semiconductor laser device as the example of nitride compound semiconductor device.But, should be understood that the present invention is suitable for the nitride compound semiconductor device of any other type.Fig. 1 a is the schematic cross section of the nitride compound semiconductor device of present embodiment, and Fig. 1 b is the top view of Fig. 1 a.Fig. 3 b is in this embodiment of the invention, handling on the substrate 10 before the growing nitride semiconductive thin film, has not handled the schematic cross section of substrate 10, and Fig. 3 a is the top view of Fig. 3 b.In these figures, unified expression in-plane.For example, by in the mode of arranging nitride semiconductor growing layer 11 of handling on the substrate 10 shown in Fig. 3 a and Fig. 3 b, make the nitride semiconductor laser device shown in Fig. 1 a and Fig. 1 b with structure as shown in figure 19.
By having the mode of handling growing nitride semiconductor growing layer 11 on the substrate 10 in the cutting zone 16 formed thereon, make the nitride semiconductor laser device of present embodiment as sunk part.With regard to this nitride semiconductor laser device, at first, how explanation is made and has been handled substrate 10 with reference to the accompanying drawings.In the present embodiment, suppose to adopt n type GaN substrate as handling substrate 10.
The thick SiO of sputtering deposit 1 μ m on the whole surface of n type GaN substrate at first 2Film or analog.Next, by the normal optical carving technology, form striated photoresist pattern along [1-100] direction, make described photoresist pattern have the wide opening of 5 μ m, and the distance at center to the adjacent stripes center from a certain striped along [11-20] direction (hereinafter this distance being called spacing) is 400 μ m.Next, by the dry etch technique such as RIE (reactive ion etching, reactive ion etching), etching SiO 2With n type GaN substrate, thereby form groove depth Y with 5 μ m and cutting zone 16 with A/F X of 5 μ m.After this, adopt HF (hydrofluoric acid) or analog, remove SiO as etchant 2Adopt this method manufacturing to have the cutting zone 16 shown in Fig. 3 a and Fig. 3 b formed thereon and the substrate of processing 10 of oncus 19 (being non-cutting zone).
The above-mentioned SiO of vapor deposition 2The method that is adopted may not be a sputtering deposit, can also be electron beam deposition, plasma CVD etc.The spacing of photoresist pattern may not be aforesaid 400 μ m, and all right change is with the width of the suitable nitride semiconductor laser device that will make.Handling the engraving method that forms 16 employings of cutting zone on the substrate 10 can be dry etching or wet etching.
Having handled substrate 10 can form by the method that directly forms cutting zone 16 as mentioned above on the surface of n type GaN substrate, perhaps can be by at first growth is by the nitride semiconductor thin film that materials such as GaN, InGaN, AlGaN, InAlGaN constitute on the surface of n type GaN substrate, the method for carrying out cutting afterwards forms.
On the substrate of making as mentioned above of processing 10, suitably adopt known technology such as MOCVD, epitaxial growth nitride semiconductor growing layer 11 as shown in figure 19 is to make the nitride semiconductor laser device shown in Fig. 1 a and Fig. 1 b.
Therefore, nitride semiconductor laser device shown in Fig. 1 a and Fig. 1 b has at the nitride semiconductor growing layer of making as mentioned above 11 of handling formation on the substrate 10 with cutting zone 16, and described nitride semiconductor growing layer 11 has stacked in order a plurality of nitride semiconductor thin films as shown in figure 19.And, on the surface of nitride semiconductor growing layer 11, form the laser stripe (laser stripe) 12 that serves as the laser waveguide and laser stripe 12 is clipped in the middle and is used for the SiO that electric current limits with being provided for 2Film 13.At laser stripe 12 and SiO 2On the surface of film 13, form p lateral electrode 14.On the other hand, on the bottom surface of handling substrate 10, form n lateral electrode 15.In addition, the surface portion that is positioned at the p lateral electrode 14 on the laser stripe 12 is just formed rising striped (elevatedstripe) 18.
On handling substrate 10, form after the nitride semiconductor growing layer 11, adopt suitable known technology, make nitride semiconductor laser device with aforesaid oncus structure.Therefore, no longer described in detail with regard to this respect.Afterwards, will be because of arranging that a plurality of nitride semiconductor laser devices that nitride semiconductor growing layer 11 forms are divided into independent devices handling on the substrate 10 (wafer).Specifically, at first, along being parallel to the direction splitting of [11-20] direction (referring to Fig. 1 a and Fig. 1 b), so that be divided into rectangular shown in Fig. 7 a and Fig. 7 b, each is rectangular to have a plurality of nitride semiconductor laser devices with wafer.Here, in the present embodiment, cavity length along the length of resonant cavity direction (i.e. [1-100] direction), is 600 μ m promptly.But cavity length may not equal described value, and cavity length may preferably be in any value of 300 μ m in 1200 mu m ranges.The rectangular chip that is divided into that will so be split into then, thus make each nitride semiconductor laser device separated from one another.After a while, will be elaborated to how carrying out the chip separation.
According to above-mentioned explanation, make the nitride semiconductor laser device shown in Fig. 1 a and Fig. 1 b.Here, will be from laser stripe 12 central authorities to cutting the distance at 16 edges, zone be made as " d ".In the present embodiment, establish d=40 μ m.Should be noted that for the easy to understand cross section structure when generating the cross section of the nitride semiconductor laser device shown in Fig. 1 a and Fig. 1 b, that carries out position that chip separates and hereafter actually carries out chip to separate the cutting zone at place different.
In the nitride semiconductor laser device shown in Fig. 1 a and Fig. 1 b, p lateral electrode 14 is by Mo/Au, Mo/Pt/Au, single Au layer etc., begins to form near a side of nitride semiconductor growing layer 11 more from it.In the present embodiment, adopt SiO 2Film 13 is as the dielectric film that carries out the electric current restriction.As an alternative, can adopt ZrO, TiO 2Deng material as dielectric film.
In this nitride semiconductor laser device, growing nitride semiconductive thin film and be grown between the flatness of the nitride semiconductor thin film on the oncus and have correlation as described below in cutting zone 16 how.
When on having the substrate of processing 20 in cutting zone 16 formed thereon, beginning epitaxial growth, shown in Fig. 4 a, the growing nitride semiconductive thin film, as the grown on top part 21 on the summit portion 23 that is positioned at oncus with as being positioned at the lateral parts 24 in cutting zone 16 and the cutting region growing part 22 on the bottom surface portions 25.Before the growing nitride semiconductive thin film, establish the A/F and the degree of depth that are formed at the cutting zone 16 of handling on the substrate 20 and be respectively X and Y.In addition, establish and begin to be parallel to the line that extends on described surface from the surface of the summit portion 23 of oncus and formed cutting regional edge boundary line 26.Here, in cutting zone 16, the area of section of establishing the part that is centered on by lateral parts 24, bottom surface portions 25 and cutting regional edge boundary line 26 is A.Therefore, area of section A equals X * Y.
In the epitaxially grown starting stage, shown in Fig. 4 a, be what to be separated by lip-deep nitride semiconductor thin film the grown on top part 21 that forms and the cutting region growing part 22 that forms by the nitride semiconductor thin film on lateral parts 24 that grows in cutting zone 16 and the bottom surface portions 25 of the summit portion 23 that grows in oncus.Carrying out along with the nitride semiconductor thin film growth shown in Fig. 4 b, grows in the grown on top part 21 on the summit portion 23, by growth part 27, is connected to the cutting region growing part 22 that grows in the cutting zone 16.Like this, the area of section of establishing the cutting region growing part 22 that so is grown in the cutting zone 16 is B, and the ratio of establishing area of section B and above-mentioned area of section A is C.Adopt this to fill the degree in cutting zone 16 than value representation nitride semiconductor thin film.
For example, shown in Fig. 6 a, in cutting zone 16, arrange nitride semiconductor thin film, the former is thoroughly filled, and, at this moment, think that compactedness C is 100% no matter so whether the surface of the nitride semiconductor thin film of growth is smooth until the latter.On the other hand, shown in Fig. 6 b,, so just calculate compactedness C according to the aforementioned calculation method if the nitride semiconductor thin film (being cutting region growing part 22) that cutting zone 16 is not arranged in is wherein thoroughly filled, thus C=(B/A) * 100%.On the contrary, shown in Fig. 6 c, if grown on top part 21 growths along cross growth are very fast, make and still keep cavity 31 in the cutting zone 16, the different piece of nitride semiconductor thin film (being grown on top part 21) will be met on those cavities 31 so, as a result, the surface flatness of nitride semiconductor thin film is inferior, works hardly to reducing crackle.Therefore, do not consider the example just mentioned in the present embodiment.
Adopt following manner estimation flatness.By making wafer in the method for arranging the nitride semiconductor growing layer 11 that constitutes by a plurality of nitride semiconductor thin films on the substrate 10 of handling shown in Fig. 1 a and Fig. 1 b, that have cutting zone 16 formed thereon, before being etched with formation oncus structure, observation post gets wafer at the optical interference microscopically, to measure the p layer thickness.Adopt the index of the variation of p layer thickness in the wafer surface as flatness.Specifically, the design load of supposing the p layer thickness is 0.670 μ m, measures the p layer thickness on 20 points in wafer plane, calculates the average deviation σ of the measurement result that so obtains.This average deviation σ is illustrated in the intensity of variation between the thickness that records on described 20 points.Average deviation σ is big more, the various characteristics of nitride semiconductor laser device, and for example the variation of FFP, threshold current, slope efficiency etc. is big more.In order to suppress the property difference of nitride semiconductor laser device, described average deviation σ must be reduced to below 0.01.Incidentally, the computational methods of average deviation σ are as follows: at first try to achieve poor between the mean value of each one-tenth-value thickness 1/10 that records on 20 points and 20 measured values, again with the absolute value addition summation of these differences, at last with tried to achieve and divided by 20.
Fig. 5 shows, before being etched with formation oncus structure, and the relation between the compactedness C in nitride semiconductor thin film filling cutting zone 16 and the intensity of variation of p layer thickness.The contents are as follows shown in the curve among Fig. 5.If compactedness C is greater than 80%, then the average deviation σ of p layer thickness increases suddenly; If compactedness C is smaller or equal to 80%, then the average deviation σ of p layer thickness keeps very little.For example, be 70% o'clock manufacturing nitride semiconductor laser device at compactedness C, the average deviation σ of p layer thickness is 0.0034 μ m so, this is a splendid result.
For example, can be by the method for control nitride semiconductor thin film gross thickness, or by the A/F X in control cutting zone 16 and the method for degree of depth Y, the compactedness C in cutting zone 16 is reduced to below 80% or 80%.Here, the gross thickness of nitride semiconductor thin film (hereinafter referred gross thickness) expression, in having the substrate of processing 10 in cutting zone 16 formed thereon, the thickness on the surface of the nitride semiconductor growing layer 11 that forms to stacked various nitride semiconductor thin film in order from its surface that does not form the part in cutting zone 16.That is to say, its expression, form laser stripe 12 (referring to Fig. 1 a) after, from the surface of handling the part that does not form cutting zone 16 on the substrate 10 to the thickness on the surface that is positioned at the laser stripe 12 on the nitride semiconductor growing layer 11.Here, do not comprise SiO 2Film 13 and p lateral electrode 14.
Seek out good film flatness, at the A/F X in cutting zone 16 during greater than 100 μ m, grow in cutting region growing part 22 on the bottom surface portions 25 in cutting zone 16 with the growth identical, thereby obtain identical with it thickness with the lip-deep grown on top part 21 of the summit portion 23 that grows in the oncus that does not form cutting zone 16.Therefore, when gross thickness be 0.8 times of degree of depth Y of cutting zone 16 or when lower, the compactedness C in cutting zone 16 is smaller or equal to 80%.
When the A/F X in cutting zone 16 more than or equal to 2 μ m, but during smaller or equal to 30 μ m, the opening in cutting zone 16 is narrow, makes the raw material atom and the molecule that form nitride semiconductor thin film can't fully enter cutting zone 16.Therefore, the speed of growth that grows in the cutting region growing part 22 on the bottom surface portions 25 in cutting zone 16 is lower than the speed of growth of the summit portion 23 lip-deep grown on top parts 21 that grow in the oncus that does not form 16 places, cutting zone, so the former thickness is little than the latter.Therefore, when gross thickness be 3 times of degree of depth Y of cutting zone 16 or when lower, the compactedness C in cutting zone 16 is smaller or equal to 80%.
When the A/F X in cutting zone 16 greater than 30 μ m, but when being less than or equal to 100 μ m, the value of X drops between above-mentioned two scopes, therefore, when gross thickness be cutting zone 16 degree of depth Y twice or when lower, the compactedness C in cutting zone 16 is smaller or equal to 80%.Incidentally, if the A/F X in cutting zone 16 is less than 2 μ m, with the inept state that occurs shown in Fig. 6 c.Therefore, in the present embodiment, the A/F X that establishes cutting zone 16 is more than or equal to 2 μ m.
That is estimated also has, and is formed with on the substrate of processing 10 in cutting zone 16 formed crackle when arranging the nitride semiconductor growing layer of being made up of various nitride semiconductor thin films 11 according to above-mentioned explanation thereon.The result is as follows.When compactedness C smaller or equal to 80% the time, the crack density in the film is 0 crackle/cm 2When compactedness C more than or equal to 80% the time, the crack density in the film is 3 to 4 crackle/cm 2And when compactedness C was 100%, the crack density in the film was about 10 crackle/cm 2That is to say, make it smaller or equal to 80%, might produce the nitride semiconductor laser device that p layer thickness variation degree reduces, the nitride semiconductor thin film flatness is good and the crackle generation reduces by reducing compactedness C.
Afterwards, the chip that the nitride semiconductor laser device that so produces is divided into separation.Before chip separated, at first the splitting wafer was to form resonator surface.Now, with reference to the accompanying drawings this implementation method is illustrated.Fig. 7 b shows along the part of the schematic cross section of the wafer of the direction splitting that is parallel to [11-20] direction (referring to Fig. 1 a and Fig. 1 b), it is its top view that the purpose of splitting wafer is to be divided into bar and Fig. 7 a that the splitting surface is formed with resonator surface.
Be formed with thereon on the substrate of processing 10 in cutting zone 16, stacked nitride semiconductor growing layer 11, (referring to Fig. 1 a), each p lateral electrode pad 40 is by such as SiO to form p lateral electrode pad 40 and p lateral electrode 14 in its surface 2The dielectric film of film 13 constitutes.At these p lateral electrode pad 40 enterprising line lead bondings.It is thick to 1 μ m that P lateral electrode pad 40 is typically about 100nm.Nitride semiconductor growing layer 11 has the current-limiting layer that is positioned at inside, and, adopting this layer to realize that each p lateral electrode pad 40 is made of a p lateral electrode 14 separately in " the flush type electric current limit laser device " of electric current restriction.In addition, on the top surface of p lateral electrode pad 40, form rising striped 18, and, n lateral electrode 15 on the bottom surface of handling substrate 10, formed.Shown in Fig. 7 a, the distance of establishing between the edge in two edges of p lateral electrode pad 40 and adjacent with those edges of p lateral electrode pad 40 respectively cutting zone 16 is respectively M and N.
Shown in Fig. 7 a and Fig. 7 b, on cutting zone 16, do not form p lateral electrode pad 40.This is because because nitride semiconductor growing layer 11 is positioned at the air spots on the cutting zone 16, form such as SiO on this surface, place 2Dielectric film, will cause cracking, connecting dislocation, hole, local thin part etc.Compare with the zone in addition, zone on the cutting zone 16, the electrical insulating property that these region lists reveal is low, and causes the leakage of current.
In addition, even when thoroughly being filled in cutting zone 16, do not find visible groove or depression, be arranged in the process that nitride semiconductor thin film wherein fills gradually that the nitride semiconductor thin film in the cutting zone 16 also can produce defective, dislocation, crackle etc. in cutting zone 16.Therefore, on the surface that is positioned at the nitride semiconductor growing layer 11 on the cutting zone 16, form SiO 2Deng causing low electrical insulating property.Therefore, if on cutting zone 16 or depression, form p lateral electrode pad 40, in those zones, may observe spontaneous emission light.This spontaneous emission only produces when leakage current is flowed through nitride semiconductor laser device.At the 5 μ m places, edge in distance cutting zone 16 or farther place when forming p lateral electrode pad 40, (, do not observe spontaneous emission light referring to a) place beyond the zone of Fig. 1 from laser stripe 12.Therefore, equal 5 μ m from the edge in cutting zone 16 to all being preferably greater than of two edges of p lateral electrode pad 40 apart from M and N.
Present embodiment relates to a kind of ridge-striped (ridge-stripe) type laser, described laser by use be formed on the nitride semiconductor growing layer 11 such as SiO 2Dielectric film realized the electric current restriction, also present embodiment can be applied to the laser of any other type, VSIS (V-channeled substrate inner stripe, V-shaped groove substrate interior striped) the type laser that for example in nitride semiconductor growing layer 11, has current-limiting layer.In such laser, on the surface of nitride semiconductor growing layer 11, be not used in the dielectric film that carries out the electric current restriction, and p lateral electrode pad 40 is made of p lateral electrode 14 separately.Should be noted that in this manual electrode pad is represented electrode pad or the electrode self on the insulating surface.And, in such laser, when in cutting zone 16, forming p lateral electrode pad 40, as in ridge-stripe laser, to flow through the gross leak electric current, penetrate thereby reduced the characteristic of nitride semiconductor laser device and caused it to swash.It is believed that this is to be caused by the degree of crystallinity deterioration that is positioned at the current-limiting layer on the cutting zone 16.Therefore, in lasers such as VSIS type, equal 5 μ m from the edge in cutting zone 16 to also being preferably greater than of two edges of p lateral electrode pad 40 apart from M and N.
Present embodiment relates to a kind of structure, in this structure, it is p lateral electrode pad that n type GaN substrate is used as the lip-deep electrode pad of having handled substrate 10 and being formed at nitride semiconductor growing layer 11, but, present embodiment can be applied in any other structure; For example, also present embodiment can be applied in the nitride semiconductor laser device with following structure, that is: form by p N-type semiconductor N material and handle substrate 10, form the surface of nitride semiconductor growing layer 11 and the electrode pad that forms in its surface is a n type electrode pad by n type nitride semiconductor thin film.
When going between bonding, to decide according to the structure of nitride semiconductor laser device although be positioned at the diameter of the head of guide-wire tip, it is about 80 μ m usually, and therefore, the width of p lateral electrode pad 40 must be more than or equal to 80 μ m.Therefore, the spacing T in cutting zone 16 need satisfy formula T 〉=[width (more than or equal to 80 μ the m)+10 μ m of the A/F X in cutting zone 16 (more than or equal to 2 μ m)+p lateral electrode pad 40 (from two edges of p lateral electrode pad 40 to the minimum value apart from M and N sum at the edge in cutting zone 16)].As T during, in the nitride semiconductor thin film of being arranged, may crack greater than 4mm.Therefore, the spacing T in cutting zone 16 is preferably smaller or equal to 4mm.Therefore, the spacing T in cutting zone 16 is preferably greater than and equals 92 μ m, but smaller or equal to 4mm.
Be divided into rectangular shown in Fig. 7 a and Fig. 7 b with being made in a plurality of nitride semiconductor laser devices of handling on the substrate 10, afterwards, be divided into separate chip.Now, to how carrying out the chip separation illustrated with reference to the accompanying drawings.
In Fig. 7 b, chip separation point position 41 and 42 have been marked.At chip separation point position 41 and 42 places, from n lateral electrode 15 1 sides, or from nitride semiconductor growing layer 11 1 side, employing diamond pen etc. carries out the scribing operation.Afterwards, the blade that will have the acute angle blade places on the line (hereinafter being called line) that is marked, and exerts pressure on blade by using fracture equipment, thereby makes rectangular splitting under pressure.Line is preferably extended along the central authorities in cutting zone 16.But in the present embodiment, as mentioned above, the compactedness C in cutting zone 16 is smaller or equal to 80%, and therefore, cutting zone 16 is not thoroughly filled, and leaves groove, and it plays guiding function for chip separates.Therefore, even line departs from the central authorities in cutting zone 16, as long as it extends in cutting zone 16, the just danger of not peeling off (chipping) or separating along unexpected direction.
Even line is extended in 16 outsides, cutting zone and in the chip separating process, if splitting departs from line, promptly advanced along unexpected direction,, will go on along the groove in the cutting zone 16 in case the crack arrives cutting zone 16.Thereby make adjacent nitride semiconductor laser device avoid wrecking.We think, it is all different with the respective attributes of nitride semiconductor thin film on the flat that is grown in non-cutting zone that the crack can not proceed to degree of crystallinity, planar orientation and other attributes that reason outside the cutting zone 16 is to be arranged in the nitride semiconductor thin film in the cutting zone 16.
In the present embodiment, shown in Fig. 7 a and Fig. 7 b, preferably on each oncus, promptly on the non-cutting zone between two adjacent cutting zones, make a nitride semiconductor laser device.But, also may take any other structure, for example, on each oncus, promptly on the non-cutting zone between two adjacent cutting zones, make two or more nitride semi-conductor laser devices.
Shown in Fig. 8 a and Fig. 8 b, can carry out the scribing operation in chip separation point position 52 and 53, but can only be arranged in the resonator surface lateral section in cutting zone 16, thereby line 50 only is formed in the middle of the described marginal portion.Also can form the line shown in dotted line line 51.Even when adopting this method to carry out the scribing operation, may realize under good rate of finished products that also chip separates.Can form line as the solid line (not shown).
Separate by chip, obtain independently nitride semiconductor laser device as shown in Figure 9 as above-mentioned realization.In the present embodiment, utilize the groove that is arranged in cutting zone 16 to implement chip and separate, described groove is that cutting zone 16 is not arranged in the result that nitride semiconductor thin film is wherein thoroughly filled.Compare with the conventional method that in the chip separating step, newly is formed for the groove that chip separates, this method has reduced the infringement to nitride semiconductor thin film, prevent the decline of nitride semiconductor laser device characteristic, and allowed under good rate of finished products, to carry out the chip separation.
Alternatively, shown in Figure 10 a and 10b, can carry out chip in the following manner separates, promptly, form two stripe-shaped sunk parts 66, afterwards, in the folded flat site of those two stripeds, the bottom surface or nitride semiconductor growing layer 11 (as shown in Figure 1a) side surface of wafer carried out the scribing operation.Utilize this structure, in the chip separating process, even extend along unexpected direction in the crack, the sunk part 66 that is positioned at both sides can prevent that also fracture extension from arriving its outside, thereby makes contiguous nitride semiconductor laser device avoid infringement.So, carry out the scribing operation in folded between sunk part 66, the flat site, need not to carry out the scribing operation, thereby might under good rate of finished products, implement the chip separation at sunk part 66 places as the chip separation point position 60 that indicates among Figure 10 b and 61.Shown in 10a, formed line can be dotted line line 62, or only carries out scribing at the resonator surface lateral section and handle and the line 63 of formation, or solid line line 64, or leaves the solid line line 65 of not drawing part.
Second embodiment
Next, with reference to relevant drawings the second embodiment of the present invention is illustrated.Present embodiment and hereinafter embodiment all relate to nitride semiconductor laser device as the semiconductor device example.But, should be understood that the present invention is applicable to the semiconductor device of any other kind.Figure 11 a is that schematic cross section and Figure 11 b of the semiconductor device of present embodiment is the top view of Figure 11 a.Figure 12 b is in this embodiment of the invention, is handling on the substrate 10 before the growing nitride semiconductive thin film, and the schematic cross section and Figure 12 a that have handled substrate 10 are the top views of Figure 12 b.In Figure 11 a, 11b, 12a and 12b, the unified high preferred orientation that indicates.
In the nitride semiconductor laser device of present embodiment, by the substrate of processing 10 that the nitride-based semiconductor substrate that is formed with on it as the cutting zone 16 of sunk part constitutes, further has the striated SiO that extends to form along [1-100] direction at the place, both sides of oncus 19 (being non-cutting zone) 2Wall.Handled the top of substrate 10 at this, growing nitride semiconductor growing layer 11, and make nitride semiconductor laser device thus.With regard to this nitride semiconductor laser device, at first how to make and handled substrate 10 with reference to description of drawings.In the present embodiment, suppose to adopt n type GaN substrate as handling substrate 10.
At first, on the whole surface of n type GaN substrate, the thick SiO of sputtering deposit 1 μ m 2Film etc.Next,, form striated photoresist pattern, make photoresist have the wide opening of 5 μ m, and be 250 μ m from the distance of central authorities along [11-20] direction to the central authorities of next striped of a striped along [1-100] direction by the normal optical carving technology.Next, by dry etch technique such as RIE (reactive ion etching), etching SiO 2With n type GaN substrate, be that 5 μ m, A/F X are the cutting zone 16 of 5 μ m to form groove depth Y.After this, adopt HF (hydrofluoric acid) to wait as etchant removal SiO 2The substrate 10 of handling that is formed with cutting zone 16 and oncus 19 on it adopts this mode to make.
In the present embodiment, by vapor deposition SiO 2Method on the surface of n type GaN substrate, form SiO 2Film.As an alternative, can on the surface of n type GaN substrate, form the dielectric film etc. of any other kind.Form above-mentioned SiO 2Method may not be sputtering deposit, can also be electron beam deposition, plasma CVD etc.The spacing of photoresist pattern may not be aforesaid 250 μ m, and it can change, to adapt to the width of the nitride semiconductor laser device that will make.In the present embodiment, by forming cutting zone 16 in the method etching.As an alternative, can be by formation cutting zones 16 such as wet etchings.
The substrate of processing 10 that adopts this mode to make, can form by the mode that directly on the surface of n type GaN substrate, forms cutting zone 16 as mentioned above, perhaps can be by the nitride semiconductor thin film that at first growth is made of GaN, InGaN, AlGaN, InAlGaN etc. on the surface of the nitride-based semiconductor substrate outside n type GaN substrate or the n type GaN substrate or on the different substrate, the mode of carrying out cutting afterwards forms.
After adopting this mode to form to have the substrate of processing 10 in cutting zone 16 thereon, position, go up vapor deposition SiO at oncus 19 (that is, non-cutting zone) 2, to form SiO 2Film.Next, along the both sides of oncus 19, adopt the normal optical lithography, width is the striated photoresist pattern of D on formation [1-100] direction.Here, the photoresist pattern adopts a kind of mode to form, that is: the side extended line in cutting zone 16 overlaps with the sidewall surfaces of photoresist pattern.Afterwards, by the wet etching of dry etching or employing HF (hydrofluoric acid) etc., etching SiO 2Film is up to the surface that exposes n type GaN substrate.Form in this way and handled substrate 10, shown in Figure 12 a and Figure 12 b, be formed with cutting zone 16 and oncus 19 thereon, and the striated SiO that has width D, thickness T and extend along place, both sides [1-100] direction of oncus 19 2 Wall 17.
In the present embodiment, SiO 2Wall 17 is by SiO 2Constitute.As an alternative, this wall can be by SiO 2Any material in addition constitutes, for example Al 2O 3, TiO 2, ZrO or W.Such as Al 2O 3, TiO 2, ZrO or W any material have selectivity on the following meaning: attempting when its surface forms GaN or AlGaN film, the growth of GaN or AlGaN or does not slowly perhaps exist fully.When the both sides along oncus 19 formed the wall that is made of this class selective material, these walls had prevented that GaN or the raw-material atom of AlGaN and molecule from flowing into cutting zone 16.This makes such as SiO 2, Al 2O 3, TiO 2, ZrO or W selective material become the preferred material of described wall.
Forming SiO in the manner described above 2During wall 17, if be formed at SiO on the oncus 19 2The thickness T of film so, just is difficult to form the uniform SiO of thickness less than 50nm in the scope of wafer surface 2Film.Otherwise, forming SiO in the manner described above 2During wall 17, if be formed at SiO on the oncus 19 2The thickness T of film is greater than 3 μ m, disadvantageously, and from SiO 2The stress of film will act on to nitride semiconductor thin film.Therefore, forming SiO 2Under the situation of wall 17, be formed at the SiO on the oncus 19 2The thickness T of film is preferably greater than and equals 50nm, but smaller or equal to 3 μ m.
On the other hand, if the SiO on the direction that is parallel to [11-20] direction 2The width D of wall 17 disadvantageously, at this moment, is difficult to carry out described technology, thereby is difficult to form SiO less than 1 μ m 2Wall 17.Otherwise, if described width D greater than 25 μ m, also is worthless, at this moment, from SiO 2The stress of film will act on nitride semiconductor thin film.Therefore, on the direction that is parallel to [11-20] direction, SiO 2The width D of wall 17 is preferably greater than and equals 1 μ m, but smaller or equal to 25 μ m.
In addition, if the degree of depth Y in the cutting zone 16 of Xing Chenging is less than 1 μ m in this manner, cutting zone 16 is just filled by nitride semiconductor growing layer 11.This strain that will cause appearing in the nitride semiconductor growing layer 11 can not obtain discharging, thereby causes the generation of crackle.Otherwise, if degree of depth Y more than or equal to 20 μ m, in the back in the chip separating step of Shi Shiing, to wafer polishing when its thickness is the 100 μ m left and right sides, wafer may rupture.Therefore, the degree of depth Y in cutting zone 16 is preferably greater than and equals 1 μ m, but smaller or equal to 20 μ m.
On the substrate of making according to above-mentioned explanation of processing 10, suitably adopt known technology such as MOCVD, that epitaxial growth is made of a plurality of nitride semiconductor thin films, be the nitride semiconductor growing layer 11 of example with structure shown in Figure 19, to make the nitride semiconductor laser device shown in Figure 11 a and Figure 11 b.
Figure 13 is the schematic cross section of wafer of nitride semiconductor thin film of having grown thereon, it is conceived to as mentioned above to arrange nitride semiconductor growing layer 11 on the substrate 10 handling, has handled the SiO that substrate 10 is formed with cutting zone 16 and oncus 19 on it and forms along the both sides of above-mentioned oncus 19 2Wall 17.As shown in figure 13, growing nitride semiconductive thin film, its conduct: the grown on top part 75 of middle body that is positioned at the summit portion 71 of oncus 19; The inflow of two marginal portions that is positioned at the summit portion 71 of oncus 19 prevents part 74, and part has formed SiO in described two edges 2Wall 17a and 17b are (corresponding to the SiO among Figure 11 a 2Wall 17); And be arranged in the lateral parts 72 in cutting zone 16 and the cutting region growing part 77 on the bottom surface portions 73.Inflow prevents that part 74 is connected to cutting region growing part 77 by growth part 76.
As shown in figure 13, has SiO owing to handle substrate 10 2 Wall 17a and 17b prevent that part 74 has the profile of rising so flow into.Can allow SiO like this 2The raw material atom of wall 17a and 17b inhibition nitride semiconductor thin film and molecule also move to the cutting zone 16 thus from summit portion 71 migrations of oncus 19.Flow into thus and prevent that part 74 has the rising profile, help more effectively to suppress the raw material atom of nitride semiconductor thin film and molecule from summit portion 71 migrations of oncus 19 and move to thus the cutting zone 16.
Specifically, even the surface of the raw material atom of nitride semiconductor thin film and the molecule attached grown on top part 75 on the summit portion 17 that is grown in oncus 19, inflow prevents that part 74 from also will suppress its migration, and moves to grown on top part 75 thus and to the lateral parts 72 and the bottom surface portions 73 in cutting zone 16.Therefore, atom and the molecule that has been attached to the surface of grown on top part 75 only moves on the surface of grown on top part 75.This has improved the surface flatness of grown on top part 75, and helps to form the uniform nitride semiconductor thin film of thickness.Inflow prevents that part 74 is about 10 μ m to 30 μ m along the width that is parallel to the direction of [11-20] direction.
In present embodiment and the 3rd embodiment that illustrates later, " flatness " is meant the surface flatness of grown on top part 75 and 95 (being illustrated hereinafter, referring to Figure 16) and the surface flatness that is arranged in the nitride semiconductor thin film on those grown on top parts 75 and 95.As shown in figure 13, the edge is perpendicular to SiO 2The cross sectional shape that cut on the plane of the bearing of trend of wall 17a and 17b can be with SiO 2Wall 17a is the rectangle of example, or any other shape, for example SiO 2Wall 17b.
When adopting this mode to arrange nitride semiconductor growing layer 11, if the A/F X in cutting zone 16 less than 1 μ m, so, shown in Figure 14 a, cutting zone 16 will thoroughly be filled by cutting region growing part 77, thereby crack.Perhaps, shown in Figure 14 b, the grown on top part 75 that grows in oncus 19 surfaces is met on cutting zone 16 until the different piece of grown on top part 75 along cross growth, thereby stays cavity 51.This has reduced the surface flatness of grown on top part 75, and produces little effect to reducing crackle.Therefore, the A/F X in cutting zone 16 need be more than or equal to 1 μ m.
As mentioned above, flow into and to prevent that part 74 from making and on the grown on top part 75 on the summit portion 71 that is formed at oncus 19, obtain the surface of good flatness and become possibility.Have thus on the grown on top part 75 of good flatness, stacked in order a plurality of nitride semiconductor thin films, forming structure nitride semiconductor growing layer 11 as shown in figure 19, and adopt this mode to make nitride semiconductor laser device shown in Figure 11 a.Suitably adopt known technology to form nitride semiconductor growing layer 11, therefore, no longer provide detailed description on the one hand at this such as MOCVD.
Be formed at as mentioned above on the surface of handling this nitride semiconductor growing layer 11 on the substrate 10, forming laser stripe 12 and SiO 2Film 13, the former act as the laser light waveguide, and the latter is clipped in the middle laser stripe 12 and plays a part the electric current restriction.At laser stripe 12 and SiO 2On the surface of film 13, form p lateral electrode 14, and, n lateral electrode 15 on the bottom surface of handling substrate 10, formed.Here, the middle body that is positioned at the surface of the p lateral electrode 14 on the laser stripe 12 just is formed rising striped 18.If the central authorities of laser stripe 12 are to SiO 2The distance that wall 17 is positioned at the edge of laser stripe 12 1 sides is " e ".In the present embodiment, this distance " e " equals 40 μ m.
In addition, in this nitride semiconductor laser device, from its side near nitride semiconductor growing layer 11, p lateral electrode 14 is made of Mo/Au, Mo/Pt/Au, single Au layer etc.In the present embodiment, adopt SiO 2Film 13 is as the dielectric film of restriction electric current.As an alternative, might adopt ZrO, TiO 2Deng material as dielectric film.It should be noted that, in order to make the cross section structure easy to understand, Figure 11 a and 11b show the cross section of mononitride semiconductor laser device, make chip separation point position that described nitride semiconductor laser device adopts and are different from hereinafter described actual and carry out the position that chip separates, and promptly the cutting zone 16.
Suitably adopting known technology, arranging that on handling substrate 10 after the nitride semiconductor growing layer 11, making has the nitride semiconductor laser device of oncus structure as mentioned above, therefore, no longer is elaborated with regard to this respect.Afterwards, will be by a plurality of nitride semiconductor laser devices formed thereon are separated into individual devices handling substrate 10 (wafer) to go up layout nitride semiconductor growing layer 11.Here, at first remove and handled the part of substrate 10, thereby make wafer be as thin as about 100 μ m.After this, on the bottom surface of handling substrate 10, form n lateral electrode 15.Next, along being parallel to the direction splitting wafer of [11-20] direction (seeing Figure 11 a and 11b), forming resonator surface, thereby in view of the above wafer is divided into rectangularly, each is rectangular to have a plurality of nitride semiconductor laser devices, shown in Figure 15 a and 15b.Here, in the present embodiment, cavity length promptly, is 600 μ m along the length of resonant cavity direction (i.e. [1-100] direction).But cavity length may not necessarily equal described value, and it can be to be preferably placed at any value of 300 μ m in 1200 mu m ranges.Afterwards, on resonator surface, by electron beam deposition etc. alternately vapor deposition by SiO 2And TiO 2The dielectric film that constitutes is to form the dielectric multilayer reflectance coating.This dielectric multilayer reflectance coating may not be necessarily by SiO 2/ TiO 2Constitute, but can be by for example SiO 2/ Al 2O 3Constitute.
Adopt this mode to make shown in Figure 15 a and 15b, have the rectangular of position a plurality of nitride semiconductor laser devices thereon.Figure 15 b is along being parallel to the direction splitting wafer of [11-20] direction (shown in Figure 11 a and 11b) and the part of the rectangular schematic cross section that obtains, and the purpose of splitting wafer is to form resonator surface and Figure 15 a is the top view of Figure 15 b.
Shown in Figure 15 a and 15b and in structure rectangular, be formed with cutting zone 16 thereon and be formed with SiO along the both sides of oncus 19 2On the substrate of processing 10 of wall 17, arrange nitride semiconductor growing layer 11, form p lateral electrode pad 80 and p lateral electrode 14 (shown in Figure 11 a and 11b) on the surface of nitride semiconductor growing layer 11, each p lateral electrode pad 80 is by such as SiO 2The dielectric film of film 13 constitutes.Because the lead-in wire bonding is to implement on the surface of p lateral electrode pad 80, so, set its thickness usually and be approximately 100nm to 1 μ m.Here, nitride semiconductor growing layer 11 has the current-limiting layer that is positioned at inside, and in " the flush type electric current limit laser device " that carry out the electric current restriction with described current-limiting layer, each in the p lateral electrode pad 80 all is made of separately p lateral electrode 14.In addition, on the top surface of the aforesaid p lateral electrode of structure pad 80, form rising striped 18, and, on the bottom surface of handling substrate 10, form n lateral electrode 15.Shown in Figure 15 a, the distance of establishing from the both sides of p lateral electrode pad 80 to the edge in adjacent with these both sides of p lateral electrode pad 80 respectively cutting zone 16 is respectively P and Q.
Shown in Figure 15 a and 15b, on cutting zone 16, do not form the p lateral electrode pad 80 that forms according to above-mentioned explanation.This be because, because the air spots of nitride semiconductor growing layer 11 on the cutting zone 16, so on this surface, place, form such as SiO 2Dielectric film will cause cracking, connecting dislocation, hole, local thin part etc.Compare with the zone beyond 16 tops, cutting zone, these zones demonstrate low electrical insulating property, thereby cause electric current to leak.
In addition, even when thoroughly being filled in cutting zone 16, do not find visible groove or depression, be arranged in the process that nitride semiconductor thin film wherein fills gradually that the nitride semiconductor thin film in the cutting zone 16 also can produce defective, dislocation, crackle etc. in cutting zone 16.Therefore, on the surface that is positioned at the nitride semiconductor growing layer 11 on the cutting zone 16, form SiO 2Deng causing low electrical insulating property.Therefore, if on cutting zone 16 or depression, form p lateral electrode pad 80, in those zones, may observe spontaneous emission light.This spontaneous emission only produces when leakage current is flowed through nitride semiconductor laser device.In addition, prevent that to the inflow of 30 μ m part 74 from being that both sides along oncus 19 form because width on the direction that is parallel to [11-20] direction is about 10 μ m, therefore, it is worthless forming p lateral electrode pads 80 in those zones.
Based on above stated specification, when forming p lateral electrode pad 80 more than or equal to 30 μ m places, (, do not observe aforesaid spontaneous emission light referring to a) zone beyond the zone of Figure 11 from laser stripe 12 at the edge in distance cutting zone 16.Therefore, all be preferably greater than to the distance P two edges of p lateral electrode pad 80 and Q by the edge in cutting zone 16 and equal 30 μ m.
Present embodiment relates to a kind of ridge-stripe laser, described laser by be formed on the nitride semiconductor growing layer 11 such as SiO 2Dielectric film realized the electric current restriction, also present embodiment can be applied to the laser of any other type, for example have VSIS (V-channeled substrate inner stripe) the type laser of the current-limiting layer that is positioned at nitride semiconductor growing layer 11.In such laser, on the surface of nitride semiconductor growing layer 11, be not used in the dielectric film of electric current restriction, and p lateral electrode pad 80 is made of separately p lateral electrode 14.And, in such laser, when being to form p lateral electrode pad 80 in the cutting zone 16, as in ridge-stripe laser, to flow through the gross leak electric current, penetrate thereby reduced the characteristic of nitride semiconductor laser device and caused it to swash.We think that this is to cause owing to the degree of crystallinity that is positioned at the current-limiting layer on the cutting zone 16 reduces.Therefore, in lasers such as VSIS type, also be preferably greater than to the distance P at two edges of p lateral electrode pad 80 and Q from the edge in cutting zone 16 and equal 30 μ m.
Present embodiment relates to a kind of structure, in this structure, it is p lateral electrode pad that n type GaN substrate is used as the lip-deep electrode pad of having handled substrate 10 and being formed at nitride semiconductor growing layer 11, but, present embodiment can be applied in any other structure; For example, present embodiment can be applied in the nitride semiconductor laser device with following structure: form by p N-type semiconductor N material and handle substrate 10, form the surface of nitride semiconductor growing layer 11 and be n type electrode pad by n type nitride semiconductor thin film at its electrode pad of forming of surface.
When going between bonding, decide according to the structure of nitride semiconductor laser device although be positioned at the diameter of the head of guide-wire tip, it typically is about 80 μ m, therefore, the width of p lateral electrode pad 80 must be more than or equal to 80 μ m.Therefore, the spacing T between two adjacent cutting zones 16 must satisfy formula T 〉=[width of p lateral electrode pad 80 (more than or equal to 80 μ m)+60 μ m (distance P between the both sides of p lateral electrode pad 80 and the limit in cutting zone 16 and apart from the minimum value of Q sum)].If the spacing T between the adjacent cutting zone 16 then is difficult to make nitride semiconductor laser device less than 140 μ m.Therefore, the spacing T between the adjacent cutting zone 16 is preferably greater than and equals 140 μ m.As T during, in the nitride semiconductor thin film of being arranged, may crack greater than 4mm.Therefore, the spacing T in adjacent cutting zone 16 is preferably greater than and equals 140 μ m, but smaller or equal to 4mm.
Afterwards, with the same among first embodiment, to separating with the above-mentioned rectangular chip that carries out shown in Figure 15 b, to make discrete nitride semiconductor laser device as Figure 15 a.Now, to how carrying out the chip separation illustrated with reference to the accompanying drawings.
In the present embodiment, at first, in the chip separation point position 81 shown in Figure 15 b or 82 places, chip separation point position carry out scribing and handle.Chip separation point position 82 is located on the end face of handling the nitride semiconductor growing layer of arranging in the cutting zone 16 that forms on the substrate 10 11 and chip separation point position 81 is positioned on the bottom surface of handling substrate 10 parts that is positioned at just under the cutting zone 16.Line is preferably placed at the central authorities in cutting zone 16.But in the present embodiment, as mentioned above, cutting zone 16 is not thoroughly filled by nitride semiconductor growing layer 11, leaves chip is separated the groove that plays guiding function.Therefore, even line departs from the central authorities in cutting zone 16,, just do not peel off or along the danger of unexpected direction separation as long as it extends in cutting zone 16.
In addition, when line was extended in the outside in cutting zone 16, in the chip separation process, line may be departed from the crack, thereby extends along unexpected direction.Even extend along unexpected direction by this way in the crack, in case the crack arrives adjacent cutting zone 16, it will extend along the groove of 16 inside, cutting zone.Thereby make adjacent nitride semiconductor laser device avoid wrecking.
In the present embodiment, shown in Figure 15 a and Figure 15 b, on each oncus 19, promptly on the non-cutting zone between the adjacent cutting zone 16, make a nitride semiconductor laser device.As an alternative, also may make a plurality of nitride semiconductor laser devices at this place.In the present embodiment, each cutting zone 16 is made of a sunk part.As an alternative, also each cutting zone may be formed and have a plurality of sunk parts and be clipped in narrow flat between these sunk parts.
Employing is adopted to be formed with SiO on it according to the said method of present embodiment 2The substrate of processing 10 of wall 17 is made a plurality of nitride semiconductor laser devices, described SiO 2The thickness T of wall 17 is 500nm, and the width D on the direction that is parallel to [11-20] direction is 3 μ m.In the nitride semiconductor laser device of made, randomly draw 100 and measure its FWHM vertical and horizontal direction FFP.Here, think the FFP that shown FWHM its design load ± those nitride semiconductor laser devices in 1 ° the scope are acceptables.The result is that the number of the nitride semiconductor laser device that the FWHM of the FFP that is shown meets the demands is 92.On the contrary, in the nitride semiconductor laser device that the routine techniques that adopts previous explanation is made, find only can accept for 30.By comparison, the method for present embodiment obviously provides and has obtained the greatly rate of finished products of raising.
Reason is, in the zone that makes nitride semiconductor laser device, the inflow that forms along the both sides of oncus 19 prevents that part 74 from helping to suppress the raw material atom of nitride semiconductor thin film and molecular migration to cutting zone 16.That is to say that surface flatness is improved in the zone that makes nitride semiconductor laser device, therefore, make the thickness of each nitride semiconductor thin film that forms nitride semiconductor growing layer 11 even.
In addition, adopt the substrate of processing 10 that is formed with cutting zone 16 on it, can allow the 11 interior strain that exists of nitride semiconductor growing layer in the scope of wafer surface, become inhomogeneous, thereby make it act on different directions.Can allow the strain that is present in the nitride semiconductor growing layer 11 obtain discharging like this.In addition, make the cutting zone not exclusively be filled the release that will promote strain by nitride semiconductor growing layer 11.Therefore, there is not crackle to produce.
The 3rd embodiment
Next, with reference to relevant drawings the third embodiment of the present invention is illustrated.Figure 16 is in the present embodiment, has at the partial schematic cross-sectional view of handling the wafer of the nitride semiconductor thin film of growth on the substrate 10.In the present embodiment, different with second embodiment, do not form SiO along the edge of handling oncus 19 on the substrate 10 (being non-cutting zone) 2Wall.
Figure 16 has the schematic cross section of handling the wafer of the nitride semiconductor thin film of growth on the substrate 10 such, is formed with cutting zone 16 on the substrate 10 handling.As shown in figure 16, the growing nitride semiconductive thin film, it is as the grown on top part 95 that is arranged in summit portion 91 cores of oncus 19, two inflows near the marginal portion in cutting zone 16 that are positioned at the summit portion 91 of oncus 19 prevent part 94 and are positioned at the lateral parts 92 in cutting zone 16 and the cutting region growing part 97 on the bottom surface portions 93.Inflow prevents that part 94 is connected to cutting region growing part 97 by growth part 96.
As shown in figure 16, in the present embodiment, although do not form SiO 2Wall prevents from part 94 to prevent in the part 94 in these inflows but formed inflow with the rising profile, and the thickness of the nitride semiconductor thin film of being grown is greater than the thickness of grown on top part 95, to form difference in height.In following explanation, represent this difference in height with H.Inflow prevents that the reason that the thickness difference between the nitride semiconductor growing layer 11 in part 94 and the grown on top part 95 produces is: flow into the speed of growth that prevents nitride semiconductor thin film in the part 94 (being two marginal portions of the summit portion 91 of oncus 19 near cutting zones 16), be higher than the speed of growth of the nitride semiconductor thin film of grown on top part 95 (being the zone that does not comprise two marginal portion on the summit portion 91 of oncus 19).Inflow prevents in part 94 and the grown on top part 95 that the greatest differences of the speed of growth comes from the difference of evaporating possibility once more between the nitride semiconductor thin film, that is, once be adsorbed on the evaporation once again and do not form the possibility of nitride semiconductor thin film from the aufwuchsplate of the raw material atom of the nitride semiconductor thin film on the aufwuchsplate of nitride semiconductor thin film and molecule.
Specifically, the material atom and the molecule that have been attached to the surface of the nitride semiconductor thin film on the summit portion 91 of the oncus 19 that grows between the cutting zone 16 are at first crossed over the zone that the aufwuchsplate migration moves to energy stabilization in other words, in described zone, material atom and molecule combine with the atom and the molecule on surface, to form nitride semiconductor thin film.If these atoms and molecule can not move to the energy stabilization zone in the time of predetermined length, they will evaporate once more from aufwuchsplate.In addition, have been found that on the surface of substrate, to form cutting zone 16 o'clock, just as handling on the substrate 10, in the summit portion 91 of the oncus between cutting zone 16 19, the most stable zone of energy is two marginal portion near cutting zone 16.In these marginal portions near cutting zone 16, Zheng Fa possibility is low once again.Therefore, in two marginal portions of summit portion 91 near cutting zone 16 of oncus 19, the speed of growth of nitride semiconductor thin film is higher than other parts of the summit portion 91 of oncus 19, therefore, formed inflow and prevented part 94, the thickness of the nitride semiconductor thin film of growing at this place is greater than the thickness of the nitride semiconductor thin film in the grown on top part 95.
These inflows prevent that part 94 is by handling growing GaN or the formation of AlGaN layer on the substrate 10.Contrast between GaN and the AlGaN shows that when arranging the GaN layer, raw material atom and the molecule of GaN have more strong migration aptitude.Therefore, the GaN raw material atom and the molecule that have been attached on the summit portion 91 of oncus 19 move usually, and move to thus in the cutting zone 16, it allows to grow as the thick GaN layer of cutting region growing part 97 on the surface of lateral parts 92 and bottom surface portions 93, and allows the formation and the little inflow to about about 10nm of height difference H on the surface of grown on top part 95 to prevent part 94.On the contrary, when arranging the AlGaN layer, AlGaN raw material atom and molecule (especially Al) only have weak migration aptitude.Therefore, the AlGaN raw material atom and the molecule that have been attached to the summit portion 91 of oncus 19 do not move in the cutting zone 16, but still remain on the summit portion 91 of oncus 19.Summit portion 91 migrations that AlGaN raw material atom on the summit portion 91 of oncus 19 and molecule are crossed over oncus 19 have been remained in.Here, because two marginal portions of the summit portion 91 of oncus 19 are aforesaid energy stabilization zone, therefore, in these zones, raw-material atom of AlGaN and molecule are fettered, and fail to be evaporated once more, formed film on the contrary, as a result, the thickness of the AlGaN layer of being grown prevents part 94 greater than grown on top part 95 thereby formed to flow into.When the Al content among the AlGaN more than or equal to 2% the time, the inflow that is made of the AlGaN layer of being grown prevents that the thickness of part 94 is big.In this way, prevent part 94 owing to formed to flow into, the AlGaN raw material atom and the molecule that have been attached to the surface of grown on top part 95 only move on the surface of grown on top part 95.Can provide possibility for formed grown on top part 95 has the surface of good flatness like this.The inflow of Xing Chenging prevents that the width Z (referring to Figure 16) of part 94 on the direction that is parallel to [11-20] direction is about 10 μ m to 30 μ m like this.
Like this, be formed with thereon on the substrate of processing 10 of cutting zone 16 and oncus 19, the nitride semiconductor growing layer 11 that layout is made of a plurality of nitride semiconductor thin films, thereby make a plurality of nitride semiconductor laser devices, that nitride semiconductor growing layer 11 has is aforesaid, on the surface of grown on top part 95 with flow into and prevent the height difference H that forms between the top of part 94.In the nitride semiconductor laser device of made, randomly draw 100 and measure its FWHM vertical and horizontal direction FFP.Here, think the FFP that shown FWHM its design load ± those nitride semiconductor laser devices in 1 ° the scope are acceptables.Figure 17 is the graph of a relation between height difference H and the number that passes through assessment acceptable nitride semiconductor laser device.As shown in figure 17, in height difference H during more than or equal to 150nm, the number of acceptable nitride semiconductor laser device is more than or equal to 85, thereby high finished product rate is provided.Otherwise when height difference H during less than 150nm, the number of acceptable nitride semiconductor laser device is smaller or equal to 40, and rate of finished products sharply descends.Its reason is: in the nitride semiconductor laser device of height difference H less than 150nm, be arranged in the thickness of each nitride semiconductor thin film on the summit portion 91 of oncus 19, not only in the wafer surface scope, change, even in single nitride semiconductor laser device, also have variation.Therefore, want under high finished product rate, to make nitride semiconductor laser device, must make the surface of grown on top part 95 and flow into height difference H between the top prevent part 94 more than or equal to 150nm.That is to say, utilization is more than or equal to the height difference H of 150nm, when on handling substrate 10, forming the nitride semiconductor growing layer 11 that constitutes by a plurality of nitride semiconductor thin films, might in the surface of each nitride semiconductor thin film on the summit portion 91 that is arranged in oncus 19, obtain the surface of good flatness, thereby reduce the varied in thickness of each nitride semiconductor thin film.
In addition, when adopting AlGaN form to flow into as mentioned above to prevent part 94, even the GaN of growth with strong migration aptitude after this flows into and prevent that part 94 from also will suppress GaN raw material atom and molecular migration and also moving to thus in the cutting zone 16.That is to say, owing at first arranged AlGaN layer on the substrate 10 handling, make that inflow prevents to have big height difference H between the surface of part 94 and grown on top part 95 with weak migration aptitude.Even arrange the GaN layer with strong migration aptitude after this, GaN also will be fettered, and avoid growing into the lateral parts 92 that is positioned at cutting zone 16 and the cutting region growing part 97 on the bottom surface portions 93.
Even at first handling on the substrate 10 under the situation of arranging the GaN layer, if the thickness of GaN layer smaller or equal to 0.5 μ m, so by stacked in order subsequently nitride semiconductor thin film, for example, as shown in figure 19 from n type Al 0.062Ga 0.938N first coating 101 is to p type GaN contact layer 109, also might form height difference H and prevent part 94 more than or equal to the inflow of 150nm.On the other hand, under the situation of GaN layer thickness greater than 0.5 μ m, GaN raw material atom and molecule will move and flow into thus in the cutting zone 16, thereby cause the remarkable growth of the cutting region growing part 97 on lateral parts 92 and the bottom surface portions 93.Therefore, shown in Figure 21 b, cutting zone 16 is almost thoroughly filled by GaN.The migration that this has just further promoted in cutting zone 16 makes the uneven thickness of GaN layer, has reduced the surface flatness of grown on top part 95.Based on these facts, when as shown in figure 19 nitride semiconductor growing layer 11 of arrangement, thickness by making the n type GaN layer 100 that contacts with the surface of handling substrate 10 might suppress to form the raw material atom of n type GaN layer 100 and the inflow of molecule smaller or equal to 0.5 μ m.Can pass through from Al 0.062Ga 0.938N first coating 101 begins growth, and forms nitride semiconductor growing layer 11 handling the mode of not arranging n type GaN layer 100 on the substrate 10.Adopt this mode, also can under the surface of good flatness, form nitride semiconductor growing layer 11.
As mentioned above, by being formed with the mode of handling growth AlGaN on the substrate 10 in cutting zone 16 thereon, form inflow and prevent part 94.Even have been found that to substitute growing GaN, (provide raw-material NH in the unit interval as V group element N by control block substrate (susceptor) temperature and raw-material mol ratio V/III 3The mole flow velocity with provide in the unit interval as the ratio between mole flow velocity of the raw-material TMGa of the element Ga of III family) method, also might suppress the migration of GaN raw material atom and molecule, and form thus and grown on top part 95 between the inflow that has more than or equal to the height difference H of 150nm prevent part 94.Provided the explanation of handling the growth conditions of growing GaN on the substrate 10 that is formed with cutting zone 16 thereon below, formed inflow prevents that height difference H between part 94 and grown on top part 95 surfaces is more than or equal to 150nm.The block substrate temperature is approximately equal to the surface temperature of handling substrate.
Usually, on handling substrate 10 during growing n-type GaN layer 100 (as shown in figure 19), to have handled the block substrate temperature of substrate 10 (wafer) be 1075 ℃ in placement on it.Under this condition, raw material atom and the molecule of n type GaN move, and flow on a large scale in the cutting zone 16, therefore, can not form the inflow with enough big height difference H and prevent part 94.In order to address this problem, the temperature of block substrate is made as 1025 ℃, promptly, lower 50 ℃ than common block substrate temperature, and, under this temperature during growing n-type GaN, formed inflow prevents that the height difference H between the surface of part 94 and grown on top part 95 from being 300nm, promptly greater than 150nm.We think that its reason is: the block substrate temperature is low, and to have caused handling the surface temperature of substrate 10 lower, thereby suppressed the migration of n type GaN raw material atom and molecule (Ga atom, N atom etc.).
On the other hand, with regard to raw-material mol ratio V/III, although the raw material mol ratio V/III of growing n-type GaN layer 100 is generally 1033, the raw material mol ratio V/III of growing n-type GaN layer 100 is 2066 here, i.e. the twice of common mol ratio.Although under common raw material mol ratio, grown on top part 95 and inflow prevent that the height difference H between the part 94 is about 10nm, but at raw material mol ratio V/III is 2066, promptly be higher than at 2000 o'clock, height difference H is about 320nm, prevents part 94 thereby formed the enough big inflow of height difference H.This be because, in GaN raw material atom and molecule attached in the growing film surface, and when on the growing film surface, moving under the heat energy effect, if raw material mol ratio V/III height then provides NH with high amount 3, make NH 3In the N atom and the Ga atom among the TMGa react rapidly, be absorbed in the film with the form of GaN.That is to say that when raw material mol ratio V/III was high, GaN raw material atom and molecule (for example Ga atom and the N atom) migration on the growing film surface was fettered, the result when arranging the AlGaN layer, has formed the inflow with big height difference H and has prevented part 94.On the contrary, when raw material mol ratio V/III is low, so that NH to be provided in a small amount 3, therefore, the Ga atom that has been attached to the growing film surface can't react rapidly with the N atom and form GaN.The move distance lengthening that this makes GaN raw material atom and molecule such as the Ga atom be produced by migration, thus promote it to flow into cutting zone 16.That is to say, raw material mol ratio V/III is made as equals or be higher than 2000, might limit GaN raw material atom and molecule in the lip-deep migration of growing film, therefore, might form inflow and prevent part 94 with gratifying big height difference H, specifically, the height difference H of counting from the surface of grown on top part 95 is more than or equal to 150nm.
As mentioned above, when on handling substrate 10, arranging the nitride semiconductor growing layer 11 that constitutes by a plurality of nitride semiconductor thin films, in order to lay out such n type GaN layer 100, make formed inflow prevent that height difference H between part 94 and the grown on top part 95 is more than or equal to 150nm, at first, be under 1025 ℃ the condition, only to arrange n type GaN layer 100 in the block substrate temperature, afterwards the block substrate temperature is risen to 1075 ℃, arrange except that multiple quantum well active layer 105, from Al 0.062Ga 0.938N first coating 101 is to each layer of p type GaN contact layer 109.Incidentally, multiple quantum well active layer 105 is to arrange under 700 ℃ to 800 ℃ temperature, and this is that the vapour pressure of In is too high, makes In to be adsorbed in the film because under 1075 ℃.
Alternatively, only arrange n type GaN layer 100 under more than or equal to 2000 condition at raw material mol ratio V/III, afterwards, raw material mol ratio V/III smaller or equal to 2000 condition under, arrange at least from Al 0.062Ga 0.938N first coating 101 to n type Al 0.062Ga 0.938Each layer of N the 3rd coating 103.For each layer from n type GaN ducting layer 104 to p type GaN contact layers 109 of follow-up layout, raw material mol ratio V/III can be more than or equal to 2000, also can be smaller or equal to 2000.
Adopt this method, by on the substrate of processing 10 that has under given conditions the n type GaN layer 100 that forms, arranging nitride semiconductor growing layer 11, might form and grown on top part 95 between height difference H prevent part 94 more than or equal to the inflow of 150nm.Finally, this makes formation become possibility by the nitride semiconductor growing layer 11 that nitride semiconductor thin film stacked, that have the excellent surface flatness in order constitutes.When forming n type GaN layer 100, aforesaid two kinds of conditions can be combined; Specifically, it can form more than or equal to 2000 o'clock when the block substrate temperature is 1025 ℃ and at raw material mol ratio V/III.
In addition, during forming nitride semiconductor growing layer 11, form and flow into when preventing part 94, make to flow into and prevent that the width Z of part 94 on the direction that is parallel to [11-20] direction is littler, help to widen the flat of oncus 19, thereby make these parts be more suitable for making nitride semiconductor laser device thereon.In addition, the migration aptitude of GaN raw material atom and molecule is strong more, and formed width Z just may be narrow more.But too strong migration aptitude will cause the injection to cutting zone 16, and this is worthless.Therefore, the width Z that preferably inflow is prevented part 94 is controlled at 10 μ m between the 30 μ m.
The application require respectively on May 10th, 2004 and on June 10th, 2004 in the patent application No.2004-139919 of Japan's submission and the priority of 2004-172291, at this it is introduced in full with for referencial use.

Claims (16)

1. method of making nitride compound semiconductor device, described method comprises:
First step, on the nitride-based semiconductor substrate that its surperficial at least a portion is a nitride-based semiconductor, or by arranging on such nitride-based semiconductor substrate on the substrate that nitride semiconductor thin film forms, formation forms thus and has handled substrate as the cutting of at least one sunk part zone with as the spine portion in non-cutting zone; With
Second step is all arranged the nitride semiconductor layer part that is made of a plurality of nitride semiconductor thin films being formed on the described surface of having handled described cutting zone on the substrate and described spine portion,
Wherein, in described first and second steps,
To be made as A along the area of section that cuts perpendicular to the plane of the bearing of trend of described sunk part, described sunk part and begin from the described surface of described spine portion is parallel to the plane institute region surrounded of this surface of this spine portion extending, and
The occupied area of section of described nitride semiconductor thin film that is arranged in the described sunk part is made as B,
The B/A that represents the filling extent of nitride semiconductor thin film described in the described sunk part so is 0.8 or littler.
2. the method for claim 1,
Wherein, in described first step, in described cutting zone, formed described sunk part has the A/F greater than 100 μ m, and
Wherein, in described second step, it is 0.8 times of the degree of depth of described sunk part or lower to the gross thickness on the surface of described nitride semiconductor layer part from the described surface of described spine portion.
3. the method for claim 1,
Wherein, in described first step, in described cutting zone, formed described sunk part has greater than 30 μ m but is less than or equal to the A/F of 100 μ m, and
Wherein, in described second step, it is 2 times of the degree of depth of described sunk part or lower to the gross thickness on the surface of described nitride semiconductor layer part from the described surface of described spine portion.
4. the method for claim 1,
Wherein, in described first step, in described cutting zone, formed described sunk part has more than or equal to 2 μ m but smaller or equal to the A/F of 30 μ m, and
Wherein, in described second step, it is three times of the degree of depth of described sunk part or lower to the gross thickness on the surface of described nitride semiconductor layer part from the described surface of described spine portion.
5. the method for claim 1, described method further comprises:
Third step, form electrode pad being arranged on the described nitride semiconductor layer part described surface of having handled substrate, that be formed at described second step, on described substrate, form a plurality of nitride compound semiconductor devices thus, connect to realize the outside at the enterprising line lead bonding of described electrode pad
Wherein, in described third step, on described cutting zone, do not form described electrode pad.
6. method as claimed in claim 5,
Wherein, in described third step, form described electrode pad more than or equal to 5 μ m places at the edge in the described cutting of distance zone.
7. the method for claim 1,
Wherein, in described first step, described spine portion has more than or equal to 92 μ m but smaller or equal to the width of 4mm.
8. the method for claim 1,
Wherein, in being sandwiched in two described spine portion between the adjacent cutting zone, form a nitride compound semiconductor device.
9. the method for claim 1,
Wherein, in being sandwiched in two described spine portion between the adjacent cutting zone, form a plurality of nitride compound semiconductor devices.
10. the method for claim 1,
Wherein, be positioned at just described described cutting zone of having handled substrate below the bottom surface of part of described nitride-based semiconductor substrate on or carry out scribing on the end face of described nitride-based semiconductor substrate, realize that thus chip separates.
11. method as claimed in claim 5, described method further comprises:
The 4th step, the described substrate of having handled of splitting on the vertical direction of the first direction that extends with the described cutting zone of described nitride compound semiconductor device has the rectangular of a plurality of described nitride compound semiconductor devices to form on each its; With
The 5th step is cut apart described rectangularly being parallel on the direction of described first direction, described each nitride compound semiconductor device on rectangular is divided into discrete chip, realizes that thus chip separates,
Wherein, in described the 5th step, thereby on the end face that is arranged in the described nitride semiconductor layer part on the described cutting zone or be positioned at just carry out on the bottom surface of part of the described nitride-based semiconductor substrate below the described cutting zone scribing handle form be parallel to the line of described first direction after, carry out described chip and separate.
12. method as claimed in claim 11, described method comprise the described the 4th and the 5th step,
Wherein, in described the 5th step, on the end face that is arranged in the described nitride semiconductor layer part on the described cutting zone or be positioned at just on the bottom surface of part of the described nitride-based semiconductor substrate below the described cutting zone, and, implement described chip thus and separate on the end face that is arranged in the described nitride semiconductor layer part on the described spine portion or be positioned at just and carry out scribing on the bottom surface of part of the described nitride-based semiconductor substrate below the described spine portion and handle.
13. method as claimed in claim 11, described method comprise the described the 4th and the 5th step,
Wherein, in described the 5th step, passing through on each is rectangular and forming profile is the described line of solid line.
14. method as claimed in claim 11, described method comprise the described the 4th and the 5th step,
Wherein, in described the 5th step, forming profile on each rectangular part is the described line of solid line.
15. method as claimed in claim 11, described method comprise the described the 4th and the 5th step,
Wherein, in described the 5th step, passing through on each is rectangular and forming profile is the described line of dotted line.
16. method as claimed in claim 11, described method comprise the described the 4th and the 5th step,
Wherein, in described the 5th step, in the marginal portion at the edge that on direction, forms, form described line perpendicular to described first direction.
CNB2005100701801A 2004-05-10 2005-05-10 Semiconductor device and method for fabrication thereof Active CN100392929C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2004139919A JP2005322786A (en) 2004-05-10 2004-05-10 Nitride semiconductor element and its manufacturing method
JP139919/04 2004-05-10
JP172291/04 2004-06-10

Related Child Applications (2)

Application Number Title Priority Date Filing Date
CN2007101490243A Division CN101119012B (en) 2004-05-10 2005-05-10 Method for fabrication of semiconductor device
CN2007101490239A Division CN101119011B (en) 2004-05-10 2005-05-10 Semiconductor device and method for fabrication of the same

Publications (2)

Publication Number Publication Date
CN1697273A CN1697273A (en) 2005-11-16
CN100392929C true CN100392929C (en) 2008-06-04

Family

ID=35349846

Family Applications (3)

Application Number Title Priority Date Filing Date
CN2007101490243A Active CN101119012B (en) 2004-05-10 2005-05-10 Method for fabrication of semiconductor device
CN2007101490239A Active CN101119011B (en) 2004-05-10 2005-05-10 Semiconductor device and method for fabrication of the same
CNB2005100701801A Active CN100392929C (en) 2004-05-10 2005-05-10 Semiconductor device and method for fabrication thereof

Family Applications Before (2)

Application Number Title Priority Date Filing Date
CN2007101490243A Active CN101119012B (en) 2004-05-10 2005-05-10 Method for fabrication of semiconductor device
CN2007101490239A Active CN101119011B (en) 2004-05-10 2005-05-10 Semiconductor device and method for fabrication of the same

Country Status (2)

Country Link
JP (1) JP2005322786A (en)
CN (3) CN101119012B (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070221932A1 (en) 2006-03-22 2007-09-27 Sanyo Electric Co., Ltd. Method of fabricating nitride-based semiconductor light-emitting device and nitride-based semiconductor light-emitting device
JP2009200478A (en) * 2008-01-21 2009-09-03 Sanyo Electric Co Ltd Semiconductor laser device and method of manufacturing the same
JP2011009610A (en) 2009-06-29 2011-01-13 Sharp Corp Nitride semiconductor laser device and wafer
CN102376835B (en) * 2010-08-23 2015-06-10 展晶科技(深圳)有限公司 Epitaxial substrate
CN109425315B (en) * 2017-08-31 2021-01-15 长鑫存储技术有限公司 Test carrier and test method of semiconductor structure
CN112567496A (en) * 2018-08-22 2021-03-26 株式会社村田制作所 Device substrate and assembly substrate
CN117219710B (en) * 2023-09-06 2024-08-16 广东中图半导体科技股份有限公司 Graphical composite substrate, preparation method thereof and LED epitaxial wafer

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5254873A (en) * 1991-12-09 1993-10-19 Motorola, Inc. Trench structure having a germanium silicate region
US5528615A (en) * 1993-07-20 1996-06-18 Mitsubishi Denki Kabushiki Kaisha Semiconductor laser and method of producing the semiconductor laser
JP2000082867A (en) * 1998-07-03 2000-03-21 Nichia Chem Ind Ltd Manufacture of nitride semiconductor laser element
JP2000277437A (en) * 1999-03-24 2000-10-06 Nichia Chem Ind Ltd Growth method for nitride semiconductor and element thereof
US20010025989A1 (en) * 2000-01-13 2001-10-04 Katsuyoshi Shibuya Semiconductor device and method of manufacturing the same
JP2002246698A (en) * 2001-02-15 2002-08-30 Sharp Corp Nitride semiconductor light-emitting device and method of manufacturing the same

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2765644B2 (en) * 1992-05-09 1998-06-18 日亜化学工業株式会社 Gallium nitride based compound semiconductor wafer cutting method
JP4432180B2 (en) * 1999-12-24 2010-03-17 豊田合成株式会社 Group III nitride compound semiconductor manufacturing method, group III nitride compound semiconductor device, and group III nitride compound semiconductor
US6566231B2 (en) * 2000-02-24 2003-05-20 Matsushita Electric Industrial Co., Ltd. Method of manufacturing high performance semiconductor device with reduced lattice defects in the active region
JP2001267242A (en) * 2000-03-14 2001-09-28 Toyoda Gosei Co Ltd Group iii nitride-based compound semiconductor and method of manufacturing the same
JP2001284291A (en) * 2000-03-31 2001-10-12 Toyoda Gosei Co Ltd Chip division method for semiconductor wafer
JP4388720B2 (en) * 2001-10-12 2009-12-24 住友電気工業株式会社 Manufacturing method of semiconductor light emitting device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5254873A (en) * 1991-12-09 1993-10-19 Motorola, Inc. Trench structure having a germanium silicate region
US5528615A (en) * 1993-07-20 1996-06-18 Mitsubishi Denki Kabushiki Kaisha Semiconductor laser and method of producing the semiconductor laser
JP2000082867A (en) * 1998-07-03 2000-03-21 Nichia Chem Ind Ltd Manufacture of nitride semiconductor laser element
JP2000277437A (en) * 1999-03-24 2000-10-06 Nichia Chem Ind Ltd Growth method for nitride semiconductor and element thereof
US20010025989A1 (en) * 2000-01-13 2001-10-04 Katsuyoshi Shibuya Semiconductor device and method of manufacturing the same
JP2002246698A (en) * 2001-02-15 2002-08-30 Sharp Corp Nitride semiconductor light-emitting device and method of manufacturing the same

Also Published As

Publication number Publication date
CN101119012B (en) 2010-04-21
CN101119011B (en) 2010-12-08
CN1697273A (en) 2005-11-16
CN101119012A (en) 2008-02-06
JP2005322786A (en) 2005-11-17
CN101119011A (en) 2008-02-06

Similar Documents

Publication Publication Date Title
US7157297B2 (en) Method for fabrication of semiconductor device
US7763527B2 (en) Semiconductor element, semiconductor device, and method for fabrication thereof
EP1104031B1 (en) Nitride semiconductor laser diode and method of fabricating the same
JP4540347B2 (en) Nitride semiconductor laser device and manufacturing method thereof
US20200321749A1 (en) Semiconductor laser diode
JP4169821B2 (en) Light emitting diode
CN100392929C (en) Semiconductor device and method for fabrication thereof
US20010013608A1 (en) Semiconductor device, its manufacturing method and substrate for manufacturing a semiconductor device
KR20020084194A (en) Production method of iii nitride compound semiconductor and iii nitride compound semiconductor element
JP2002009004A (en) Method of manufacturing nitride semiconductor, nitride semiconductor device, method of manufacturing the same semiconductor light emitting device and its manufacturing method
US20010016404A1 (en) GaN substrate including wide low - defect region for use in semiconductor element
JP4772314B2 (en) Nitride semiconductor device
JP2006134926A5 (en)
KR100639747B1 (en) Semiconductor laser, semiconductor device and their manufacturing methods
JP4679867B2 (en) Nitride semiconductor light emitting device and manufacturing method thereof
JP4890509B2 (en) Manufacturing method of semiconductor light emitting device
JP4689195B2 (en) Manufacturing method of semiconductor device
JP2004007009A (en) Manufacturing method of nitride semiconductor device
JP5530341B2 (en) Semiconductor device and manufacturing method thereof
JP4895488B2 (en) Nitride semiconductor light emitting device, manufacturing method thereof, and wafer
JP2007305635A (en) Nitride semiconductor light-emitting element
JP2011018912A (en) Nitride semiconductor device manufacturing method
JP5679699B2 (en) Nitride semiconductor light emitting device
CN113287205A (en) Method for obtaining smooth surfaces by epitaxial lateral overgrowth
JP5203412B2 (en) Nitride semiconductor light emitting device and manufacturing method thereof

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20220402

Address after: Asahi 1, Damen Machi, Fukuyama, Hiroshima, Japan

Patentee after: Sharp Fukuyama laser Co.,Ltd.

Address before: Osaka, Japan

Patentee before: Sharp Corp.

TR01 Transfer of patent right