JP2006100793A - Compound semiconductor light-emitting element - Google Patents
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本発明は、化合物半導体発光素子に関する。 The present invention relates to a compound semiconductor light emitting device.
青色ＬＥＤ等のＧａＮ層を含む化合物半導体発光素子が広く使用されるようになるに従って、さらに高い発光出力を示す化合物半導体発光素子が求められるようになってきた。 As compound semiconductor light-emitting devices including GaN layers such as blue LEDs have been widely used, there has been a demand for compound semiconductor light-emitting devices that exhibit higher light output.
ここで、従来の化合物半導体発光素子は、電気絶縁性のサファイアからなる成長基板の上にＧａＮ層を含む化合物半導体機能層を備え、その上に二つの電極を備えたものであった。この従来の化合物半導体発光素子の場合、化合物半導体機能層の二つの面のうちサファイア成長基板とは反対側の面である発光面上に設置された二つの光不透過性の電極が光を遮り、発光出力を低下させていた。 Here, the conventional compound semiconductor light emitting device includes a compound semiconductor functional layer including a GaN layer on a growth substrate made of electrically insulating sapphire, and further includes two electrodes thereon. In the case of this conventional compound semiconductor light emitting device, two light-impermeable electrodes installed on the light emitting surface, which is the surface opposite to the sapphire growth substrate, of the two surfaces of the compound semiconductor functional layer block light. The light output was reduced.
そこで、Ｃｕからなる導電性基板（熱膨張率は１６．２×１０-6／℃）／ＧａＮ層を含む化合物半導体機能層／電極がこの順で積層されてなる構成を有する化合物半導体発光素子が提案されている（例えば、特許文献１参照）。このような構成とすることにより、導電性基板の化合物半導体機能層を備えた面と反対側の面にもう一方の電極を設置するかまたは導電性基板が電極を兼ねることができるようになり、発光面には一つの電極のみを設置すればよくなる。
ＥＰ−１３８５２１５−Ａ２には、対向する二つの主面を有する基板の一方の主面上に、少なくとも、１層以上のｐ型窒化物半導体層と、ＡｌaＩｎbＧａ1-a-bＮ（０≦ａ≦１、０≦ｂ≦１、ａ＋ｂ≦１）から成る井戸層とＡｌcＩｎdＧａ1-c-dＮ（０≦ｃ≦１、０≦ｄ≦１、ｃ＋ｄ≦１）から成る障壁層とを少なくとも含む量子井戸構造を有する活性層と、１層以上のｎ型窒化物半導体層と、を有する窒化物半導体素子の製造方法であって、対向する二つの主面を有し、前記ｎ型及びｐ型窒化物半導体層よりも大きな熱膨張係数を有する成長用基板の一方の主面上に、少なくとも、ｎ型窒化物半導体層と、活性層と、ｐ型窒化物半導体層と、を成長させて接合用積層体を形成し、前記ｐ型窒化物半導体層の上に１層以上の金属層から成る第１の接合層を設ける一方、対向する二つの主面を有し、前記ｎ型及びｐ型窒化物半導体層よりも大きく、かつ前記成長用基板と同じか小さい熱膨張係数を有する基板の一方の主面上に１層以上の金属層から成る第２の接合層を設け、第１の接合層と第２の接合層とを対向させて、接合用積層体と前記基板とを加熱圧接して接合し、前記接合用積層体の成長用基板を除去する窒化物半導体素子の製造方法が記載されている。
しかし、さらに高い発光出力が求められており、金属からなる導電性基板を用いてなり、ＧａＮ層を含み、発光出力の高い化合物半導体発光素子が求められている。
Therefore, a compound semiconductor light-emitting element having a configuration in which a conductive substrate made of Cu (thermal expansion coefficient is 16.2 × 10 −6 / ° C.) / A compound semiconductor functional layer including a GaN layer / an electrode is laminated in this order. It has been proposed (see, for example, Patent Document 1). By adopting such a configuration, it becomes possible to install the other electrode on the surface opposite to the surface provided with the compound semiconductor functional layer of the conductive substrate, or the conductive substrate can also serve as the electrode. It is only necessary to install one electrode on the light emitting surface.
In EP-1385215-A2, at least one p-type nitride semiconductor layer and Al a In b Ga 1-ab N (0) are formed on one main surface of a substrate having two opposing main surfaces. ≦ a ≦ 1,0 ≦ b ≦ 1 , a + b ≦ 1 well layer made of) and Al c In d Ga 1-cd N (0 ≦ c ≦ 1,0 ≦ d ≦ 1, c + d ≦ 1) barrier layer made of A nitride semiconductor device having an active layer having a quantum well structure including at least one and an n-type nitride semiconductor layer including at least one n-type nitride semiconductor layer. At least an n-type nitride semiconductor layer, an active layer, and a p-type nitride semiconductor layer on one main surface of a growth substrate having a larger thermal expansion coefficient than the p-type and p-type nitride semiconductor layers. Forming a laminated body for bonding, and comprising a metal layer including one or more metal layers on the p-type nitride semiconductor layer; A main layer of one of the substrates having two opposing principal surfaces, larger than the n-type and p-type nitride semiconductor layers and having a thermal expansion coefficient equal to or smaller than that of the growth substrate. A second bonding layer composed of one or more metal layers is provided on the surface, the first bonding layer and the second bonding layer are opposed to each other, and the bonding laminate and the substrate are bonded by heating and pressing. In addition, a method for manufacturing a nitride semiconductor device is described in which the growth substrate of the bonding laminate is removed.
However, there is a demand for a higher light emission output, and there is a need for a compound semiconductor light emitting device that uses a conductive substrate made of metal, includes a GaN layer, and has a high light emission output.
本発明の目的は、金属からなる導電性基板を用いてなり、ＧａＮ層を含み、発光出力の高い化合物半導体発光素子を提供することにある。 An object of the present invention is to provide a compound semiconductor light emitting device that uses a conductive substrate made of metal, includes a GaN layer, and has a high light emission output.
本発明者らは、上記問題を解決するために、金属からなる導電性基板を用いてなり、ＧａＮ層を含む化合物半導体発光素子について鋭意検討した結果、本発明を完成させるに到った。 In order to solve the above-mentioned problems, the present inventors have conducted a study on a compound semiconductor light-emitting element using a conductive substrate made of a metal and including a GaN layer. As a result, the present invention has been completed.
すなわち、本発明は、〔１〕導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層がこの順で積層されてなり、該導電性基板がＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す金属材料からなる導電性基板であることを特徴とする化合物半導体発光素子、
〔２〕導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層をこの順で有し、該導電性基板がＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す金属材料からなる導電性基板であることを特徴とする化合物半導体発光素子に係るものである。
That is, the present invention comprises: [1] conductive substrate / compound semiconductor functional layer including GaN layer / electrode / adhesion improving layer / adhesion layer in this order, and the conductive substrate is thermally expanded with GaN. A compound semiconductor light emitting device characterized in that it is a conductive substrate made of a metal material having a coefficient of thermal expansion of 1.5 × 10 −6 / ° C. or less,
[2] Conductive substrate / compound semiconductor functional layer including GaN layer / electrode / adhesion improving layer / adhesive layer in this order, and the conductive substrate has a thermal expansion coefficient difference of 1.5 × 10 5 from GaN The present invention relates to a compound semiconductor light-emitting element, which is a conductive substrate made of a metal material exhibiting a thermal expansion coefficient of −6 / ° C. or lower.
さらに、本発明は、〔３〕金属材料が、Ｗ、Ｍｏ、Ｈｆ、Ｌａ、Ｔａ、Ｉｒ、Ｒｕ、ＯｓおよびＮｂからなる群より選ばれる１種以上を主体とする金属材料である〔１〕または〔２〕に記載の化合物半導体発光素子、
〔４〕金属材料が、Ｗ、Ｍｏ、Ｈｆ、Ｌａ、Ｔａ、Ｉｒ、Ｒｕ、ＯｓおよびＮｂからなる群より選ばれる１種の金属材料である〔１〕または〔２〕に記載の化合物半導体発光素子、
〔５〕導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層がこの順で積層されてなり、該導電性基板がＧａＮの熱膨張率より１．５×１０-6／℃以下小さい熱膨張率を有する金属材料からなる導電性基板である化合物半導体発光素子、
〔６〕導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層をこの順で有し、該導電性基板がＧａＮの熱膨張率より１．５×１０-6／℃以下小さい熱膨張率を有する金属材料からなる導電性基板である化合物半導体発光素子、
〔７〕金属材料が、ＷおよびＭｏからなる群より選ばれる１種以上を主体とする金属材料である〔５〕または〔６〕に記載の化合物半導体発光素子、
〔８〕金属材料が、ＷおよびＭｏからなる群より選ばれる１種の金属材料である〔５〕または〔６〕に記載の化合物半導体発光素子、
〔９〕ＧａＮ層を含む化合物半導体機能層が、少なくともｎ型の導電性を有する層、発光層を有する窒化物系化合物半導体の層、ｐ型の導電性を有する層、をこの順に有することを特徴とする〔１〕〜〔８〕のいずれかに記載の化合物半導体発光素子、
〔１０〕密着性向上層がＴｉＰｔからなる金属材料であり、接着層がＡｕＳｎからなる金属材料である〔１〕〜〔９〕のいずれかに記載の化合物半導体発光素子、
〔１１〕（１）成長基板上に、ＧａＮ層を含む化合物半導体機能層を積層して積層体１を得る工程、
（２）積層体１のＧａＮ層を含む化合物半導体機能層上に、電極、密着性向上層、接着層をこの順に積層して積層体２を得る工程、
（３）積層体２の接着層と、別に準備した導電性基板に密着性向上層を積層して得られる積層体３の密着性向上層とを貼り合せて積層体５を得る工程、または積層体２の接着層と、別に準備した導電性基板に密着性向上層、接着層を積層して得られる積層体４の接着層とを貼り合せて積層体５を得る工程、
（４）前記の（３）の工程で得られた積層体５から成長基板を除去して積層体６を得る工程、
（５）前記の（４）の工程で得られた積層体６を素子分割する工程
を、この順で有することを特徴とする〔１〕〜〔１０〕のいずれかに記載の化合物半導体発光素子の製造方法、
〔１２〕（１）成長基板上に、ＧａＮ層を含む化合物半導体機能層を積層して積層体１を得る工程、
（２）積層体１のＧａＮ層を含む化合物半導体機能層に素子分離溝を作製し、分離された化合物半導体機能層の上に、電極、密着性向上層、接着層をこの順に積層して積層体７を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極を積層し、該化合物半導体機能層と電極とに素子分離溝を作製し、分離された電極の上に、密着性向上層、接着層をこの順に積層して積層体８を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極、密着性向上層をこの順に積層し、該化合物半導体機能層と電極と密着性向上層とに素子分離溝を作製し、分離された密着性向上層の上に、接着層を積層して積層体９を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極、密着性向上層、接着層をこの順に積層し、該化合物半導体機能層、密着性向上層、接着層に素子分離溝を作製して積層体１０を得る工程、
（３）積層体７、積層体８、積層体９、積層体１０のいずれかの接着層と、
別に準備した導電性基板に密着性向上層を積層して得られる積層体３の密着性向上層とを貼り合せて積層体１１を得る工程、または積層体７、積層体８、積層体９、積層体１０のいずれかの接着層と、別に準備した導電性基板に密着性向上層、接着層を積層して得られる積層体４の接着層とを貼り合せて積層体１１を得る工程、
（４）前記の（３）の工程で得られた積層体１１から成長基板を除去して積層体１２を得る工程、
（５）前記の（２）の工程で作製された素子分離溝に合わせて、積層体１２を切断する工程を、この順で有することを特徴とする〔１〕〜〔１０〕のいずれかに記載の化合物半導体発光素子の製造方法、
〔１３〕工程（１）が、成長基板上に、少なくともｎ型の導電性を有する層、発光層を有する窒化物系化合物半導体の層、ｐ型の導電性を有する層、をこの順に積層する工程であることを特徴とする〔１１〕または〔１２〕に記載の化合物半導体発光素子の製造方法、
〔１４〕金属材料が鏡面研磨されていることを特徴とする〔１〕〜〔１３〕のいずれかに記載の化合物半導体発光素子の製造方法に係るものである。
Further, the present invention is [3] a metal material mainly comprising at least one selected from the group consisting of W, Mo, Hf, La, Ta, Ir, Ru, Os and Nb. Or the compound semiconductor light emitting device according to [2],
[4] The compound semiconductor light-emitting device according to [1] or [2], wherein the metal material is one metal material selected from the group consisting of W, Mo, Hf, La, Ta, Ir, Ru, Os, and Nb. element,
[5] Conductive substrate / compound semiconductor functional layer including GaN layer / electrode / adhesion improving layer / adhesion layer are laminated in this order, and the conductive substrate is 1.5 × 10 5 from the thermal expansion coefficient of GaN. -6 / ° C. or less, a compound semiconductor light emitting device that is a conductive substrate made of a metal material having a small coefficient of thermal expansion,
[6] Conductive substrate / compound semiconductor functional layer including GaN layer / electrode / adhesion improving layer / adhesive layer in this order, and the conductive substrate is 1.5 × 10 −6 from the thermal expansion coefficient of GaN. Compound semiconductor light-emitting element which is a conductive substrate made of a metal material having a thermal expansion coefficient of less than / ° C
[7] The compound semiconductor light-emitting element according to [5] or [6], wherein the metal material is a metal material mainly composed of one or more selected from the group consisting of W and Mo.
[8] The compound semiconductor light emitting device according to [5] or [6], wherein the metal material is one metal material selected from the group consisting of W and Mo,
[9] The compound semiconductor functional layer including the GaN layer has at least an n-type conductivity layer, a nitride-based compound semiconductor layer having a light emitting layer, and a p-type conductivity layer in this order. The compound semiconductor light-emitting device according to any one of [1] to [8],
[10] The compound semiconductor light-emitting element according to any one of [1] to [9], wherein the adhesion improving layer is a metal material made of TiPt, and the adhesive layer is a metal material made of AuSn.
[11] (1) A step of obtaining a laminate 1 by laminating a compound semiconductor functional layer including a GaN layer on a growth substrate,
(2) A step of obtaining a laminate 2 by laminating an electrode, an adhesion improving layer, and an adhesive layer in this order on the compound semiconductor functional layer including the GaN layer of the laminate 1;
(3) The step of obtaining the laminate 5 by bonding the adhesive layer of the laminate 2 and the adhesion improving layer of the laminate 3 obtained by laminating the adhesion improving layer on a separately prepared conductive substrate, or lamination Bonding the adhesive layer of the body 2 and the adhesive layer of the laminate 4 obtained by laminating the adhesion improving layer and the adhesive layer to a separately prepared conductive substrate to obtain the laminate 5;
(4) A step of removing the growth substrate from the laminate 5 obtained in the step (3) to obtain a laminate 6;
(5) The compound semiconductor light-emitting device according to any one of [1] to [10], wherein the step of dividing the multilayer body 6 obtained in the step (4) is divided in this order. Manufacturing method,
[12] (1) A step of obtaining a laminate 1 by laminating a compound semiconductor functional layer including a GaN layer on a growth substrate,
(2) An element isolation groove is formed in the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the separated compound semiconductor functional layer. Obtaining a body 7;
Alternatively, an electrode is stacked on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, an element isolation groove is formed in the compound semiconductor functional layer and the electrode, and an adhesion improving layer is formed on the separated electrode. A step of obtaining a laminate 8 by laminating adhesive layers in this order;
Alternatively, an electrode and an adhesion improving layer are laminated in this order on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an element isolation groove is formed in the compound semiconductor functional layer, the electrode, and the adhesion improving layer, and separated. A step of obtaining a laminate 9 by laminating an adhesive layer on the adhesion improving layer formed;
Alternatively, an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an element isolation groove is formed in the compound semiconductor functional layer, the adhesion improving layer, and the adhesive layer. And obtaining the laminate 10,
(3) the adhesive layer of any one of the laminate 7, the laminate 8, the laminate 9, and the laminate 10,
A step of obtaining a laminate 11 by laminating an adhesion improvement layer of a laminate 3 obtained by laminating an adhesion improvement layer on a separately prepared conductive substrate, or a laminate 7, a laminate 8, a laminate 9, A step of obtaining a laminate 11 by bonding any adhesive layer of the laminate 10 and an adhesive layer of a laminate 4 obtained by laminating an adhesion improving layer and an adhesive layer on a separately prepared conductive substrate;
(4) A step of removing the growth substrate from the laminate 11 obtained in the step (3) to obtain a laminate 12;
(5) The method according to any one of [1] to [10], further including a step of cutting the stacked body 12 in this order in accordance with the element isolation groove formed in the step (2). A method for producing the compound semiconductor light-emitting device according to claim 1,
[13] In step (1), at least an n-type conductive layer, a nitride compound semiconductor layer having a light emitting layer, and a p-type conductive layer are stacked in this order on the growth substrate. [11] or [12], the method for producing a compound semiconductor light-emitting device according to [11],
[14] The method according to any one of [1] to [13], wherein the metal material is mirror-polished.
本発明の化合物半導体発光素子は、従来の化合物半導体発光素子より高い発光出力を示すので、屋内表示用のみならず、照明用、屋外表示用、ディスプレイ用、信号灯用など高い発光出力が求められる用途に好適に使用することができ、工業的に極めて有用である。 The compound semiconductor light-emitting device of the present invention exhibits higher light output than conventional compound semiconductor light-emitting devices. Therefore, not only indoor display but also lighting, outdoor display, display, signal light, etc. It can be suitably used for industrial applications and is extremely useful industrially.
本発明の化合物半導体発光素子は、導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層がこの順で積層されてなり、該導電性基板がＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す金属材料からなる導電性基板であることを特徴とする。
また、本発明の化合物半導体発光素子は、導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層をこの順で有し、該導電性基板がＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す金属材料からなる導電性基板であることを特徴とする。
金属材料からなる導電性基板として、ＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す金属材料からなる導電性基板を用いると、理由は明らかではないが、導電性基板／ＧａＮ層を含む化合物半導体機能層／電極がこの順で積層されてなる化合物半導体発光素子の発光出力が高くなる。
The compound semiconductor light emitting device of the present invention comprises a conductive substrate / compound semiconductor functional layer including a GaN layer / electrode / adhesion improving layer / adhesive layer in this order, and the conductive substrate is thermally expanded with GaN. It is a conductive substrate made of a metal material having a coefficient of thermal expansion of 1.5 × 10 −6 / ° C. or less.
The compound semiconductor light-emitting device of the present invention has a conductive substrate / compound semiconductor functional layer including a GaN layer / electrode / adhesion improving layer / adhesive layer in this order, and the conductive substrate is thermally expanded with GaN. It is a conductive substrate made of a metal material having a coefficient of thermal expansion of 1.5 × 10 −6 / ° C. or less.
When a conductive substrate made of a metal material showing a coefficient of thermal expansion of 1.5 × 10 −6 / ° C. or less is used as the conductive substrate made of a metal material, the reason is not clear. The light emission output of the compound semiconductor light emitting device in which the conductive substrate / the compound semiconductor functional layer including the GaN layer / the electrode is laminated in this order is increased.
ＧａＮの熱膨張率は５．５９×１０-6／℃（３００Ｋ、結晶ｃ面に垂直方向）であるので、ＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率とは、４．１×１０-6以上７．１×１０-6以下の範囲であり、この場合に化合物半導体発光素子の発光出力が高くなる傾向がある。導電性基板の金属材料とＧａＮとの熱膨張率差は１．２×１０-6／℃以下（すなわち、熱膨張率が４．４×１０-6以上６．８×１０-6以下の範囲である。）がより好ましい。なお、本発明における熱膨張率は、３００Ｋ（２３℃）における線熱膨張率である。 Since the thermal expansion coefficient of GaN is 5.59 × 10 −6 / ° C. (300 K, perpendicular to the crystal c plane), the thermal expansion difference between the thermal expansion coefficient and GaN is 1.5 × 10 −6 / ° C. or less. The rate is in the range of 4.1 × 10 −6 or more and 7.1 × 10 −6 or less, and in this case, the light emission output of the compound semiconductor light emitting element tends to be high. The difference in thermal expansion coefficient between the metal material of the conductive substrate and GaN is 1.2 × 10 −6 / ° C. or less (that is, the range of the thermal expansion coefficient is 4.4 × 10 −6 or more and 6.8 × 10 −6 or less). Is more preferable. In addition, the thermal expansion coefficient in this invention is a linear thermal expansion coefficient in 300K (23 degreeC).
本発明で用いることができ、ＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す導電性基板の材料としては、具体的には、Ｗ、Ｍｏ、Ｈｆ、Ｌａ、Ｔａ、Ｉｒ、Ｒｕ、ＯｓおよびＮｂからなる群より選ばれる１種以上（以下「組成Ａ」とする。）を主体とする金属材料が挙げられる。前記の金属元素単体の各々の熱膨張率は、１０-6／℃を単位として順に、４．５、５．１、５．９、６．５、６．５、６．６、６．８、７．０、７．１であり、これらの中でも、ＧａＮとの熱膨張率差が１．２×１０-6／℃以下であるので、Ｗ、Ｍｏ、Ｈｆ、Ｌａ、Ｔａ、ＩｒおよびＲｕからなる群から選ばれる１種以上がより好ましい。そして、ＷおよびＭｏからなる群から選ばれる１種以上がさらに好ましく、Ｍｏが最も好ましい。コスト面、作製の容易さの観点から、組成Ａの群より選ばれる材料種は少ない方が好ましく、１種のみであることがより好ましい。なお、本発明においては、半金属に該当する元素（例えば、Ｓｉ、Ｇｅ等を指す。）は金属元素には含まれない。 Specific examples of the conductive substrate material that can be used in the present invention and exhibit a coefficient of thermal expansion of 1.5 × 10 −6 / ° C. or less with respect to GaN include W, Mo, and Hf. , La, Ta, Ir, Ru, Os, and Nb, and a metal material mainly composed of one or more selected from the group consisting of La, Ta, Ir, Ru, Os, and Nb (hereinafter referred to as “composition A”). The coefficient of thermal expansion of each of the metal elements is 4.5, 5.1, 5.9, 6.5, 6.5, 6.6, 6.8 in order of 10 −6 / ° C. 7.0, 7.1, and among these, the difference in thermal expansion coefficient from GaN is 1.2 × 10 −6 / ° C. or less, so W, Mo, Hf, La, Ta, Ir, and Ru One or more selected from the group consisting of And 1 or more types chosen from the group which consists of W and Mo are still more preferable, and Mo is the most preferable. From the viewpoint of cost and ease of production, the number of material types selected from the group of composition A is preferably small, and more preferably only one type. In the present invention, an element corresponding to a semimetal (for example, Si, Ge, etc.) is not included in the metal element.
さらに、本発明の導電性基板には、組成Ａとともに、Ｓｉ、Ｇｅ、Ｃｒ、Ｔｉ、Ｒｈ、Ｐｔ、Ｖ、Ｐｄ、Ｎｉ、Ｃｏ、Ｆｅ、Ａｕ、Ｚｒ、Ｂｉ、Ｃｕ、Ｓｂ、Ａｇ、Ｍｎ、Ａｌ、Ｍｇ、Ｓｎ、Ｃｄ、Ｇａ、Ｚｎ、Ｉｎ、Ｙ、Ｒｅ、Ｓｒ、Ｂａ、Ｃｅ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕからなる群より選ばれる１種以上（以下「組成Ｂ」という。）を、熱膨張係数が前記範囲を超えない限り含有させることができる。本発明の導電性基板としては、組成Ａのみからなる場合が好ましい。そして、組成ＡおよびＢ以外の元素も、不可避不純物として本発明の導電性基板用に含有されていてもよい。不可避不純物の濃度は、各々の元素の濃度として通常は１００重量ｐｐｍ以下程度である。 Furthermore, the conductive substrate of the present invention includes Si, Ge, Cr, Ti, Rh, Pt, V, Pd, Ni, Co, Fe, Au, Zr, Bi, Cu, Sb, Ag, Mn together with the composition A. , Al, Mg, Sn, Cd, Ga, Zn, In, Y, Re, Sr, Ba, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu One or more selected from the group (hereinafter referred to as “composition B”) can be contained as long as the thermal expansion coefficient does not exceed the above range. The conductive substrate of the present invention is preferably composed of only composition A. And elements other than composition A and B may also be contained for the conductive substrate of the present invention as inevitable impurities. The concentration of inevitable impurities is usually about 100 ppm by weight or less as the concentration of each element.
金属材料からなる導電性基板として、ＧａＮの熱膨張率より１．５×１０-6／℃以下小さい熱膨張率を有する金属材料からなる導電性基板を用いると、理由は明らかではないが、導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層がこの順で積層されてなる化合物半導体発光素子の発光出力がさらに高くなるので好ましい。
ＧａＮより熱膨張率が１．５×１０-6／℃以下小さい熱膨張率を有する金属材料からなる導電性基板としては、ＷおよびＭｏからなる群から選ばれる１種以上が挙げられる。コスト面、作製の容易さの観点から、選ばれる材料種は少ない方が好ましく、１種のみであることがより好ましく、Ｍｏが最も好ましい。
When a conductive substrate made of a metal material having a thermal expansion coefficient smaller than that of GaN by 1.5 × 10 −6 / ° C. or less is used as the conductive substrate made of a metal material, the reason is not clear. This is preferable because the light emission output of the compound semiconductor light emitting device in which the functional substrate / the compound semiconductor functional layer including the GaN layer / the electrode / the adhesion improving layer / the adhesive layer is laminated in this order is further increased.
Examples of the conductive substrate made of a metal material having a coefficient of thermal expansion smaller than that of GaN by 1.5 × 10 −6 / ° C. or less include one or more selected from the group consisting of W and Mo. From the viewpoint of cost and ease of production, the number of selected material types is preferably small, more preferably only one, and most preferably Mo.
また、本発明の導電性基板の導電率は、３×１０4Ｓｃｍ-1以上が好ましく、３×１０5Ｓｃｍ-1以上がさらに好ましい。導電率の上限は特にないが、通常は１×１０6Ｓｃｍ-1程度である。 Further, the conductivity of the conductive substrate of the present invention is preferably 3 × 10 4 Scm −1 or more, more preferably 3 × 10 5 Scm −1 or more. There is no particular upper limit for the conductivity, but it is usually about 1 × 10 6 Scm −1 .
導電性基板の表面粗さは、化合物半導体機能層との接着しやすさの観点から、鏡面研磨されている方が好ましい。表面粗さとしては１０００Å以下が好ましく、２００Å以下がより好ましく、１００Å以下がさらに好ましい。
導電性基板の厚さは、薄すぎると導電性基板に割れ等の損傷が生じる等があり、厚すぎると材料コストがかかる等があり、通常１０μｍ〜２ｍｍ程度にある。好ましくは１０〜５００μｍ、より好ましくは３０〜２００μｍ程度にある。
The surface roughness of the conductive substrate is preferably mirror-polished from the viewpoint of easy adhesion to the compound semiconductor functional layer. The surface roughness is preferably 1000 mm or less, more preferably 200 mm or less, and even more preferably 100 mm or less.
If the thickness of the conductive substrate is too thin, the conductive substrate may be damaged such as cracks. If it is too thick, the material cost may be high, and is usually about 10 μm to 2 mm. Preferably it is about 10-500 micrometers, More preferably, it is about 30-200 micrometers.
本発明の化合物半導体発光素子を構成する電極としては、通常用いられているｐ電極としてＡｕ、Ｐｔ、Ｐｄ、Ｎｉ／Ａｕ、Ｎｉ／ＩＴＯ、ＩＴＯ／Ａｇ、Ａｕ粒子群／Ｐｔ／Ａｇ等、ｎ電極としてＩＴＯ、ＺｎＯ、Ａｌ、Ｔｉ／Ａｌ等の金属からなる電極を用いることができる。 As the electrodes constituting the compound semiconductor light emitting device of the present invention, commonly used p electrodes are Au, Pt, Pd, Ni / Au, Ni / ITO, ITO / Ag, Au particle group / Pt / Ag, etc., n An electrode made of a metal such as ITO, ZnO, Al, Ti / Al, or the like can be used as the electrode.
本発明の化合物半導体発光素子を構成する化合物半導体機能層は、発光素子の動作に必要な多層膜を意味し、少なくともｎ型の導電性を有する層、ｐ型の導電性を有する層、これらの間に発光層を有する窒化物系化合物半導体の層からなるものが好ましく、場合によっては、これらの多層膜を高品質の結晶にするために必要な単層あるいは多層の層をも含む場合がある。発光素子の動作に必要な多層膜とは、具体的にはｎ型伝導層、ｐ型伝導層、およびこれらの間に配置された発光層を含む多層膜である。ｎ型伝導層はｎ型コンタクト層やｎ型クラッド層などの複数の層から構成されることがあり、同様にｐ型伝導層もｐ型コンタクト層やｐ型クラッド層などの複数の層から構成されることがある。高品質の結晶にするために必要な単層あるいは多層の層とは、バッファ層、厚膜層、超格子薄膜層などである。そして、通常用いられる化合物半導体機能層の構成としては、ＧａＮ、ＡｌＮ等からなるバッファ層、ｎ−ＧａＮ、ｎ−ＡｌＧａＮ等からなるクラッド層、ＩｎＧａＮ、ＧａＮ等からなる発光層、アンドープＧａＮ、ｐ−ＧａＮ等からなるクラッド層、ＭｇドープＡｌＧａＮ、ＭｇドープＧａＮからなるキャップ層が順次積層されてなるものが挙げられる（例えば、特開平６−２６０６８２号公報、特開平７−１５０４１号公報、特開平９−６４４１９号公報、特開平９−３６４３０号公報を参照。）。 The compound semiconductor functional layer constituting the compound semiconductor light-emitting device of the present invention means a multilayer film necessary for the operation of the light-emitting device, and includes at least an n-type conductivity layer, a p-type conductivity layer, A nitride compound semiconductor layer having a light emitting layer in between is preferable, and in some cases, a single layer or a multilayer layer necessary for making these multilayer films into high-quality crystals may be included. . The multilayer film necessary for the operation of the light-emitting element is specifically a multilayer film including an n-type conductive layer, a p-type conductive layer, and a light-emitting layer disposed therebetween. The n-type conductive layer may be composed of a plurality of layers such as an n-type contact layer and an n-type cladding layer, and similarly the p-type conductive layer is composed of a plurality of layers such as a p-type contact layer and a p-type cladding layer. May be. A single layer or a multilayer layer necessary for obtaining a high-quality crystal includes a buffer layer, a thick film layer, a superlattice thin film layer, and the like. The structure of the normally used compound semiconductor functional layer includes a buffer layer made of GaN, AlN, etc., a cladding layer made of n-GaN, n-AlGaN, etc., a light emitting layer made of InGaN, GaN, etc., undoped GaN, p- A cladding layer made of GaN or the like, a Mg-doped AlGaN layer, and a cap layer made of Mg-doped GaN layer are sequentially laminated (for example, JP-A-6-260682, JP-A-7-15041, JP-A-9). -64419 and JP-A-9-36430).
次に、本発明の化合物半導体発光素子の製造方法について説明する。
本発明の化合物半導体発光素子の製造方法は、（１）成長基板上に、ＧａＮ層を含む化合物半導体機能層を積層して積層体１を得る工程、
（２）積層体１のＧａＮ層を含む化合物半導体機能層上に、電極、密着性向上層、接着層をこの順に積層して積層体２を得る工程、
（３）積層体２の接着層と、別に準備した導電性基板に密着性向上層を積層して得られる積層体３の密着性向上層とを貼り合せて積層体５を得る工程、または積層体２の接着層と、別に準備した導電性基板に密着性向上層、接着層を積層して得られる積層体４の接着層とを貼り合せて積層体５を得る工程、
（４）前記の（３）の工程で得られた積層体５から成長基板を除去して積層体６を得る工程、
（５）前記の（４）の工程で得られた積層体６を素子分割する工程
を、この順で有することを特徴とする。
まず、成長基板の上に前記に挙げたような化合物半導体機能層をＭＯＣＶＤ法によりエピタキシャル成長させて積層体１を製造する。
Next, the manufacturing method of the compound semiconductor light emitting element of this invention is demonstrated.
The method for producing a compound semiconductor light emitting device of the present invention includes (1) a step of obtaining a laminate 1 by laminating a compound semiconductor functional layer including a GaN layer on a growth substrate,
(2) A step of obtaining a laminate 2 by laminating an electrode, an adhesion improving layer, and an adhesive layer in this order on the compound semiconductor functional layer including the GaN layer of the laminate 1;
(3) The step of obtaining the laminate 5 by bonding the adhesive layer of the laminate 2 and the adhesion improving layer of the laminate 3 obtained by laminating the adhesion improving layer on a separately prepared conductive substrate, or lamination Bonding the adhesive layer of the body 2 and the adhesive layer of the laminate 4 obtained by laminating the adhesion improving layer and the adhesive layer to a separately prepared conductive substrate to obtain the laminate 5;
(4) A step of removing the growth substrate from the laminate 5 obtained in the step (3) to obtain a laminate 6;
(5) It is characterized by having in this order the step of dividing the laminate 6 obtained in the step (4).
First, the compound semiconductor functional layer as described above is epitaxially grown on the growth substrate by the MOCVD method to manufacture the laminate 1.
結晶成長用の成長基板としては、従来知られた成長基板を用いることができる。
窒化物半導体成長用の成長基板としては、サファイア、ＳｉＣ、Ｓｉなどからなる成長基板が挙げられる。
As a growth substrate for crystal growth, a conventionally known growth substrate can be used.
Examples of the growth substrate for growing a nitride semiconductor include a growth substrate made of sapphire, SiC, Si, or the like.
例えば、ＭＯＣＶＤ法においては、前記成長基板を加熱し、窒素原料ガス、ガリウム原料ガス、アルミニウム原料ガス、インジウム原料ガス等を流して化合物半導体機能層の結晶を成長させる（例えば、特開平７−２４９７９５号公報、特開平９−１１６１３０号公報を参照。）。窒素原料ガスとしては通常はアンモニア（ＮＨ3）が用いられる。ガリウム原料ガス、アルミニウム原料ガス、インジウム原料ガスとしては、各金属原子に炭素数が１から３のアルキル基もしくは水素が結合した、トリアルキル化物もしくは三水素化物が、通常用いられる。 For example, in the MOCVD method, the growth substrate is heated, and a nitrogen source gas, a gallium source gas, an aluminum source gas, an indium source gas, etc. are flown to grow a compound semiconductor functional layer crystal (for example, Japanese Patent Laid-Open No. 7-249795). No., JP-A-9-116130). As the nitrogen source gas, ammonia (NH 3 ) is usually used. As the gallium source gas, aluminum source gas, and indium source gas, trialkylates or trihydrides in which an alkyl group having 1 to 3 carbon atoms or hydrogen is bonded to each metal atom are usually used.
次いで、化合物半導体機能層に前記の金属材料からなり、ＧａＮとの熱膨張率差が１．５×１０-6／℃以下の熱膨張率を示す導電性基板を接着する。接着には熱圧着、ハンダ金属による接着等の通常工業的に行われている方法を用いることができる。 Next, a conductive substrate made of the above metal material and having a thermal expansion coefficient of 1.5 × 10 −6 / ° C. or less is bonded to the compound semiconductor functional layer. For the bonding, a method which is usually performed industrially, such as thermocompression bonding or solder metal bonding, can be used.
ここで、化合物半導体機能層上には、電極、密着性向上層、接着層がこの順に積層される。密着性向上層は、電極と導電性基板間の密着性向上、及び接着時等の工程で生じる可能性がある電極機能を劣化させる相互拡散等を防止する効果がある。
密着性向上層としては、Ｃｒ、Ｔｉ、Ｎｉ、Ｖからなる群より選ばれる１種以上と、Ｗ、Ｍｏ、Ｐｔ、Ａｇ、Ｃｕからなる群より選ばれる１種以上の組み合わせが挙げられ、特にＴｉ／Ｐｔ（例えば、Ｔｉの蒸着膜とＰｔの蒸着膜の積層）が、密着性向上層の効果が高いので、好ましい。
必要に応じて密着性向上層を熱処理してもよいが、金属が球状に凝集する（ボールアップ）現象がある電極等の金属では亀裂等が生じ機能を劣化させる場合がある。この観点でもＴｉ／Ｐｔを用いると、それ抑制し機能劣化させることがなく、発光出力の高いＬＥＤを作製することができるので好ましい。
密着性向上層の厚さは、薄すぎると該機能を劣化させる等があり、厚すぎると材料コストがかかる等があり、通常１０〜５００００Å、好ましくは１００〜１００００Å、より好ましくは５００〜２０００Å程度である。これらの密着性向上層は、導電性基板上にも作製する方が好ましい。これらを設ける方法としては、種々の公知の方法が採用されるが、真空蒸着法が好ましい。
Here, an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the compound semiconductor functional layer. The adhesion improving layer has an effect of improving the adhesion between the electrode and the conductive substrate, and preventing interdiffusion or the like that deteriorates the electrode function that may occur in a process such as adhesion.
Examples of the adhesion improving layer include one or more selected from the group consisting of Cr, Ti, Ni, and V, and one or more combinations selected from the group consisting of W, Mo, Pt, Ag, and Cu. Ti / Pt (for example, lamination of a Ti vapor deposition film and a Pt vapor deposition film) is preferable because the effect of the adhesion improving layer is high.
If necessary, the adhesion improving layer may be heat-treated, but a metal such as an electrode having a phenomenon that the metal aggregates in a spherical shape (ball-up) may cause cracks or the like to deteriorate the function. From this point of view, it is preferable to use Ti / Pt because it is possible to manufacture an LED having high light emission output without suppressing it and deteriorating its function.
If the thickness of the adhesion improving layer is too thin, the function may be deteriorated. If the thickness is too thick, the material cost may be increased, and is usually 10 to 50000 mm, preferably 100 to 10,000 mm, more preferably about 500 to 2000 mm. It is. These adhesion improving layers are preferably produced also on a conductive substrate. As a method for providing these, various known methods are adopted, but a vacuum deposition method is preferable.
接着層には、通常Ｓｎ、Ｉｎ、Ｐｂ、Ｃｕ、Ｂｉ、Ｇａ、Ａｇ、Ａｕ、Ｚｎ、Ｇｅ、Ｓｉ、Ａｌ、Ｃｄ、Ｓｂ、Ｔｌ、Ｆｅ、Ｐｄからなる群より選ばれる１種以上の組み合わせが挙げられ、環境性からＰｂフリーであることが好ましく、Ａｕ−Ｓｎがより好ましい。さらに好ましくは、３００℃程度以下の低温で、ウェハ全体均一で接着強度が高く接着できるＡｕリッチＡｕ−Ｓｎ（例えばＡｕ８０％−Ｓｎ２０％）である。
接着層の厚さは、薄すぎると接着できない等があり、厚すぎると材料コストがかかる等があり、通常１００〜５００００Å、好ましくは１０００〜５００００Å、より好ましくは５０００〜３００００Å程度である。これらは、接着面の表面荒さにも依存する。
化合物半導体機能層／電極／密着性向上層／接着層として、好ましくは化合物半導体機能層／電極／Ｔｉ／Ｐｔ／Ａｕ−Ｓｎであり、これにより素子歩留まり（生産性）が高く、発光出力の高いＬＥＤを作製することができる。
導電性基板にも、電極と導電性基板間の密着性向上のために、前記同様な密着性向上層が積層され、好ましくは密着性向上層／接着層が積層される。密着性向上層としては、特にＴｉ／Ｐｔ（例えば、Ｔｉの蒸着膜とＰｔの蒸着膜の積層）が、密着性向上層の効果が高いので、好ましい。接着層としては、Ａｕ−Ｓｎが好ましく、３００℃程度以下の低温で、ウェハ全体均一で接着強度が高く接着できるＡｕリッチＡｕ−Ｓｎ（例えばＡｕ８０％−Ｓｎ２０％）がより好ましい。
The adhesive layer is usually one or more combinations selected from the group consisting of Sn, In, Pb, Cu, Bi, Ga, Ag, Au, Zn, Ge, Si, Al, Cd, Sb, Tl, Fe, and Pd. From the environmental point of view, Pb-free is preferable, and Au-Sn is more preferable. More preferably, it is Au-rich Au—Sn (for example, Au 80% —Sn 20%) which can be bonded uniformly at the low temperature of about 300 ° C. or less and with high adhesive strength.
If the thickness of the adhesive layer is too thin, it may not be adhered, and if it is too thick, the material cost may be increased, and is usually 100 to 50000 mm, preferably 1000 to 50000 mm, and more preferably about 5000 to 30000 mm. These also depend on the surface roughness of the adhesive surface.
The compound semiconductor functional layer / electrode / adhesion improving layer / adhesion layer is preferably a compound semiconductor functional layer / electrode / Ti / Pt / Au—Sn, which results in high device yield (productivity) and high light emission output. An LED can be fabricated.
Also on the conductive substrate, in order to improve the adhesion between the electrode and the conductive substrate, the same adhesion improving layer as described above is laminated, and preferably the adhesion improving layer / adhesive layer is laminated. As the adhesion improving layer, Ti / Pt (for example, lamination of a Ti vapor deposition film and a Pt vapor deposition film) is particularly preferable since the effect of the adhesion enhancement layer is high. As the adhesive layer, Au-Sn is preferable, and Au-rich Au-Sn (for example, Au 80% -Sn 20%) that can be bonded at a low temperature of about 300 [deg.] C. or lower and uniform throughout the wafer and having high adhesive strength is more preferable.
次いで、成長基板を除去する。成長基板を除去する方法としては、レーザーリフトオフ法、研磨等により除去する方法を挙げることができる（例えば、特公表２００１−５０１７７８号公報、特開平１１−２３８９１３号公報を参照。）。 Next, the growth substrate is removed. Examples of the method for removing the growth substrate include a laser lift-off method, a method for removing the growth substrate, and the like (see, for example, Japanese Patent Publication No. 2001-501778 and Japanese Patent Laid-Open No. 11-238913).
次いで、成長基板を除去後、その成長基板を除去した面に電極として、透明電極、網目状電極等を作製することもできる。例えば、成長基板であるサファイア基板直上に結晶成長した化合物半導体機能層がＧａＮである場合、レーザーリフトオフ法で成長基板を除去した面には薄膜Ｇａが残留することがあり、これを半透明電極として用いることができる。さらにＬＥＤを高出力化するために、化合物半導体発光素子や透明電極等の表面、界面を凸凹加工等してもよい。 Next, after removing the growth substrate, a transparent electrode, a mesh electrode, or the like can be produced as an electrode on the surface from which the growth substrate has been removed. For example, when the compound semiconductor functional layer crystal-grown directly on the sapphire substrate, which is the growth substrate, is GaN, the thin film Ga may remain on the surface from which the growth substrate has been removed by the laser lift-off method. Can be used. Furthermore, in order to increase the output of the LED, the surface and interface of the compound semiconductor light-emitting element and the transparent electrode may be processed to be uneven.
次いで、素子として機能させるために必要に応じた大きさに分割（素子分割）する。こうして本発明の化合物半導体発光素子を製造することができる。 Next, it is divided (element division) into a size as required in order to function as an element. Thus, the compound semiconductor light emitting device of the present invention can be manufactured.
また、前記において、ＧａＮ層を含む化合物半導体機能層と導電性基板とを貼り合せる工程の前に、素子分離を行う方法が、素子歩留まりよく、得られる発光素子の輝度がより向上するので好ましい。
すなわち、本発明の化合物半導体発光素子の製造方法は、（１）成長基板上に、ＧａＮ層を含む化合物半導体機能層を積層して積層体１を得る工程、
（２）積層体１のＧａＮ層を含む化合物半導体機能層に素子分離溝を作製し、分離された化合物半導体機能層の上に、電極、密着性向上層、接着層をこの順に積層して積層体７を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極を積層し、該化合物半導体機能層と電極とに素子分離溝を作製し、分離された電極の上に、密着性向上層、接着層をこの順に積層して積層体８を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極、密着性向上層をこの順に積層し、該化合物半導体機能層と電極と密着性向上層とに素子分離溝を作製し、分離された密着性向上層の上に、接着層を積層して積層体９を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極、密着性向上層、接着層をこの順に積層し、該化合物半導体機能層、密着性向上層、接着層に素子分離溝を作製して積層体１０を得る工程、
（３）積層体７、積層体８、積層体９、積層体１０のいずれかの接着層と、
別に準備した導電性基板に密着性向上層を積層して得られる積層体３の密着性向上層とを貼り合せて積層体１１を得る工程、または積層体７、積層体８、積層体９、積層体１０のいずれかの接着層と、別に準備した導電性基板に密着性向上層、接着層を積層して得られる積層体４の接着層とを貼り合せて積層体１１を得る工程、
（４）前記の（３）の工程で得られた積層体１１から成長基板を除去して積層体１２を得る工程、
（５）前記の（２）の工程で作製された素子分離溝に合わせて、積層体１２を切断する工程を、この順で有することを特徴とする。
In the above, a method of element isolation before the step of bonding the compound semiconductor functional layer including the GaN layer and the conductive substrate is preferable because the element yield is improved and the luminance of the light-emitting element obtained is further improved.
That is, the method for producing a compound semiconductor light emitting device of the present invention includes (1) a step of obtaining a laminate 1 by laminating a compound semiconductor functional layer including a GaN layer on a growth substrate,
(2) An element isolation groove is formed in the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the separated compound semiconductor functional layer. Obtaining a body 7;
Alternatively, an electrode is stacked on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, an element isolation groove is formed in the compound semiconductor functional layer and the electrode, and an adhesion improving layer is formed on the separated electrode. A step of obtaining a laminate 8 by laminating adhesive layers in this order;
Alternatively, an electrode and an adhesion improving layer are laminated in this order on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an element isolation groove is formed in the compound semiconductor functional layer, the electrode, and the adhesion improving layer, and separated. A step of obtaining a laminate 9 by laminating an adhesive layer on the adhesion improving layer formed;
Alternatively, an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an element isolation groove is formed in the compound semiconductor functional layer, the adhesion improving layer, and the adhesive layer. And obtaining the laminate 10,
(3) the adhesive layer of any one of the laminate 7, the laminate 8, the laminate 9, and the laminate 10,
A step of obtaining a laminate 11 by laminating an adhesion improvement layer of a laminate 3 obtained by laminating an adhesion improvement layer on a separately prepared conductive substrate, or a laminate 7, a laminate 8, a laminate 9, A step of obtaining a laminate 11 by bonding any adhesive layer of the laminate 10 and an adhesive layer of a laminate 4 obtained by laminating an adhesion improving layer and an adhesive layer on a separately prepared conductive substrate;
(4) A step of removing the growth substrate from the laminate 11 obtained in the step (3) to obtain a laminate 12;
(5) It is characterized by having the process of cut | disconnecting the laminated body 12 in this order according to the element isolation groove produced at the process of said (2).
成長基板上に結晶成長した化合物半導体機能層を、前記導電性基板と接着する前に、成長基板に達する深さの素子分離用の溝（素子分離溝）を化合物半導体結晶に形成しておく。これにより素子歩留まりが高く、発光出力の高いＬＥＤを作製することができる。この素子分離用溝の作製には、ドライエッチング、ウェットエッチング、レーザー加工、ダイサー加工等による方法が挙げられ、好ましくは、加工効率がよく、加工損傷も少ないドライエッチングである。 Before the compound semiconductor functional layer crystal-grown on the growth substrate is bonded to the conductive substrate, an element isolation groove (element isolation groove) having a depth reaching the growth substrate is formed in the compound semiconductor crystal. Thus, an LED having a high element yield and a high light emission output can be manufactured. The element isolation groove can be formed by dry etching, wet etching, laser processing, dicer processing, or the like. Preferably, dry etching is preferable because of high processing efficiency and less processing damage.
素子分離溝を形成する加工は、素子分離溝を形成する領域上の積層体数が少ない方が、加工容易さの観点から好ましく、ＧａＮ層を含む化合物半導体機能層だけであることがより好ましい。つまり、ＧａＮ層を含む化合物半導体機能層に素子分離溝を作製し、分離された化合物半導体機能層の上に、電極、密着性向上層、接着層をこの順に積層して積層体を得る工程がより好ましい。 In the process for forming the element isolation groove, the number of stacked bodies on the region where the element isolation groove is formed is preferably smaller from the viewpoint of ease of processing, and more preferably only the compound semiconductor functional layer including the GaN layer. That is, there is a process of forming an element isolation groove in a compound semiconductor functional layer including a GaN layer, and laminating an electrode, an adhesion improving layer, and an adhesive layer in this order on the separated compound semiconductor functional layer to obtain a laminate. More preferred.
この導電性基板／ＧａＮ層を含む化合物半導体機能層／電極／密着性向上層／接着層がこの順で積層されてなる化合物半導体発光素子の発光出力は、通常の低電流域（例えば２０ｍＡ）に加えて、高電流域（例えば３００ｍＡ）においても高くなる。
上記において、本発明の実施の形態について説明を行ったが、上記に開示された本発明の実施の形態は、あくまで例示であって、本発明の範囲はこれらの実施の形態に限定されない。本発明の範囲は、特許請求の範囲によって示され、さらに特許請求の範囲の記載と均等の意味及び範囲内でのすべての変更を含むものである。
The light emission output of the compound semiconductor light emitting element in which the conductive substrate / compound semiconductor functional layer including GaN layer / electrode / adhesion improving layer / adhesive layer is laminated in this order is in a normal low current region (for example, 20 mA). In addition, it becomes high even in a high current region (for example, 300 mA).
Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the terms of the claims, and further includes meanings equivalent to the description of the claims and all modifications within the scope.
以下本発明を、実施例をあげながら説明する。本発明はこれらの実施例のみに限定されるものではない。 The present invention will be described below with reference to examples. The present invention is not limited to these examples.
実施例１
ＭＯＣＶＤ法を用いて、大きさ２インチ径、厚さ４３０μｍのサファイア成長基板の（０００１）面上に結晶成長させた、次に示すＬＥＤ構造の窒化物半導体エピタキシャル結晶を準備した。すなわち、ＧａＮバッファ層５００Å、ｎ型キャリア濃度５×１０18／ｃｍ3のＳｉドープｎ型ＧａＮ層４μｍ、ｎ型キャリア濃度５×１０18／ｃｍ3、Ａｌ組成１５％のＡｌＧａＮ（Ａｌ0.15Ｇａ0.85Ｎ）層０．３μｍ、ｎ型キャリア濃度１×１０17／ｃｍ3のＳｉドープｎ型ＧａＮ層０．３μｍ、アンドープＧａＮの１５ｎｍの層とＩｎＧａＮの２．５ｎｍの層の繰り返し１０回からなる発光波長４７０ｎｍの多重量子井戸活性層、アンドープＧａＮ層１５ｎｍ、ＭｇドープＡｌ組成５％のＡｌＧａＮ層２５ｎｍ、ＭｇドープＧａＮ層０．２μｍである。サファイア成長基板上に前記の各層を成長させたものを、以下「エピ基板」とする。
Example 1
A nitride semiconductor epitaxial crystal having the following LED structure was prepared by crystal growth on the (0001) plane of a sapphire growth substrate having a size of 2 inches in diameter and a thickness of 430 μm by MOCVD. That, GaN buffer layer 500 Å, an n-type carrier concentration of 5 × 10 18 / cm 3 of Si-doped n-type GaN layer 4 [mu] m, the n-type carrier concentration of 5 × 10 18 / cm 3, Al composition 15% AlGaN (Al 0.15 Ga 0.85 N) Light emission consisting of 10 repetitions of 0.3 μm layer, Si doped n-type GaN layer 0.3 μm of n-type carrier concentration 1 × 10 17 / cm 3 , 15 nm layer of undoped GaN and 2.5 nm layer of InGaN A multi-quantum well active layer having a wavelength of 470 nm, an undoped GaN layer of 15 nm, an MgGaN-doped Al composition layer of 5% AlGaN layer of 25 nm, and an Mg-doped GaN layer of 0.2 μm. A substrate obtained by growing the above layers on a sapphire growth substrate is hereinafter referred to as an “epi substrate”.
成長後の窒化物半導体エピタキシャル結晶表面上に形成した膜厚３μｍのフォトレジスト膜から素子分離用のマスクパターンをフォトリソグラフィにより作製し、ＩＣＰドライエッチング法によりサファイア成長基板までエッチングして分離溝を形成した。ＩＣＰドライエッチングに用いたエッチングガスは、Ｃｌ2、ＣＨ2Ｃｌ2、Ａｒの混合ガスであり、ガス流量は各々２０、１０、４０ｓｃｃｍ、圧力２Ｐａ、ＩＣＰパワー２００Ｗ、バイアスパワー１００Ｗである。ドライエッチング終了後、余分のマスクを有機溶剤で除去した。 A mask pattern for element isolation is produced by photolithography from a 3 μm thick photoresist film formed on the surface of the grown nitride semiconductor epitaxial crystal, and etching is performed to the sapphire growth substrate by ICP dry etching to form an isolation groove. did. The etching gas used for ICP dry etching is a mixed gas of Cl 2 , CH 2 Cl 2 , and Ar, and the gas flow rates are 20, 10, 40 sccm, pressure 2 Pa, ICP power 200 W, and bias power 100 W, respectively. After the dry etching was completed, the excess mask was removed with an organic solvent.
次に素子分離された後の窒化物半導体エピタキシャル結晶の表面にオーミックｐ電極を形成するために、エピ基板をＮ2雰囲気中において８００℃で２０分保持して熱処理を行い、Ｍｇドープ層を低抵抗のｐ型にした。次に、窒化物半導体エピタキシャル結晶表面を熱王水（６０℃）を用いて表面処理した後、オーミックｐ電極となるＮｉ／Ａｕ電極を形成するために、真空蒸着装置にてＮｉを１５０Å、引き続いてＡｕを３００Å蒸着し、リフトオフ法により電極パターンを形成した。次にＯ2を５体積％を含むＮ2雰囲気中で５００℃で１０分間の熱処理を行うことによりＮｉＡｕオーミックｐ電極を作製した。 Next, in order to form an ohmic p-electrode on the surface of the nitride semiconductor epitaxial crystal after element isolation, heat treatment is performed by holding the epi substrate in an N 2 atmosphere at 800 ° C. for 20 minutes to reduce the Mg doped layer to a low level. Resistor p-type. Next, the surface of the nitride semiconductor epitaxial crystal is surface-treated using hot aqua regia (60 ° C.), and then Ni is deposited at 150 ° C. in a vacuum deposition apparatus to form a Ni / Au electrode that becomes an ohmic p electrode. Then, 300 μm of Au was evaporated, and an electrode pattern was formed by a lift-off method. Next, a NiAu ohmic p-electrode was produced by performing a heat treatment at 500 ° C. for 10 minutes in an N 2 atmosphere containing 5% by volume of O 2 .
次に、触針式の表面粗度測定装置による平均表面粗さ５．８ｎｍの表面鏡面研磨した、厚さ１００μｍの２インチ径Ｍｏ製の導電性基板を準備し、この表面に接着層の密着性を向上させる層としてＴｉ／Ｐｔの層を真空蒸着法により、それぞれ５００Å／５００Å形成した後、Ｎ2雰囲気中において３５０℃で３０分保持して熱処理を行った。次に接着層であるＡｕ−Ｓｎ合金層（Ａｕ８０％−Ｓｎ２０％）を５０００Å真空蒸着法で形成した。Ｍｏ導電性基板上に形成したものと同じ層構造の密着性向上層と接着層を、エピ基板のＮｉ／Ａｕオーミックｐ電極の形成された領域の上に、リフトオフ法を用いたフォトリソグラフィと真空蒸着法により形成した。 Next, a conductive substrate made of Mo having a thickness of 100 μm and having a 2-inch diameter of Mo having a mean surface roughness of 5.8 nm by a stylus type surface roughness measuring device was prepared, and the adhesion layer was adhered to the surface. A Ti / Pt layer was formed as a layer for improving the properties by vacuum vapor deposition, respectively, and then heat-treated by holding at 350 ° C. for 30 minutes in an N 2 atmosphere. Next, an Au—Sn alloy layer (Au 80% —Sn 20%) as an adhesive layer was formed by a 5000 mm vacuum evaporation method. The adhesion improving layer and the adhesive layer having the same layer structure as that formed on the Mo conductive substrate are formed on the region where the Ni / Au ohmic p-electrode is formed on the epitaxial substrate by photolithography and vacuum using the lift-off method. It formed by the vapor deposition method.
次に、接着層の形成されたエピ基板と、同じく接着層の形成されたＭｏ導電性基板とを、接着層どうしで向かい合わせ、真空熱圧着法により貼り合せた。貼り合せにおける圧力、温度、時間、荷重の条件は各々、１×１０-3Ｔｏｒｒ以下、３００℃、５分間、６０００Ｎである。貼り合せ後得られた基板（以後「貼り合せ基板」と呼ぶ。）の反りを測定したところ、基板中央で１０２μｍであった。 Next, the epitaxial substrate on which the adhesive layer was formed and the Mo conductive substrate on which the adhesive layer was also formed face each other and were bonded together by a vacuum thermocompression bonding method. The conditions of pressure, temperature, time, and load in bonding are 1 × 10 −3 Torr or less, 300 ° C., 5 minutes, and 6000 N, respectively. The warpage of the substrate obtained after bonding (hereinafter referred to as “bonded substrate”) was measured and found to be 102 μm at the center of the substrate.
次に、レーザーリフトオフ法によりサファイア成長基板を貼り合せ基板から剥離した。レーザーリフトオフに用いたレーザーはＣＷ励起Ｑスイッチパルス発振ＹＶ０4レーザーの３倍高調波（波長３５５ｎｍ）をチョッパーにより周波数１５ｋＨｚのパルスにしたものであり、３倍高調波の出力は０．４７Ｗ、レーザービーム径４０μｍである。このレーザーをサファイア成長基板側から入射させ、サファイア／ＧａＮエピ界面からＧａＮ側１７０μｍの位置に焦点位置が来るようにデフォーカスして照射した。試料を真空吸着でステージに固定し、そのステージを３５０ｍｍ/ｓｅｃで線状にスキャンし、１ライン分のスキャン終了後、３０μｍ移動させるようにスキャンしながら、試料全面にレーザーを照射させた。レーザー照射の終わった貼り合せ基板を６０℃の温湯の中に入れて、サファイア／ＧａＮエピ界面に発生しているＧａメタルをメルトさせることにより、サファイア成長基板を剥離させた。 Next, the sapphire growth substrate was peeled from the bonded substrate by a laser lift-off method. Laser used for laser lift-off is obtained by the pulse frequency 15kHz by CW pumped Q-switched pulse oscillation YV0 4 laser triple harmonic (wavelength 355 nm) chopper, the output of the third harmonic is 0.47 W, the laser The beam diameter is 40 μm. This laser was made incident from the sapphire growth substrate side, and defocused and irradiated so that the focal position was 170 μm from the sapphire / GaN epi interface to the GaN side. The sample was fixed to the stage by vacuum suction, the stage was scanned linearly at 350 mm / sec, and after scanning for one line, the entire surface of the sample was irradiated with laser while scanning to move 30 μm. The bonded substrate after the laser irradiation was put in hot water at 60 ° C., and Ga metal generated at the sapphire / GaN epi interface was melted to peel off the sapphire growth substrate.
以上の工程により、Ｍｏ導電性基板上に接着層を介してＬＥＤ機能層が貼り合わされた構造のフルウェハのＭｏ導電性基板上の発光素子が得られた。この発光素子の表面には、Ｇａメタルがわずかに残留していたが、このＧａメタル自身がｎ型ＧａＮの半透明オーミック電極に利用できるので、このまま発光素子特性を評価した。Ｍｏ導電性基板側を正極、Ｇａメタル側を負極として、電極直径２００μｍの素子に２０ｍＡの電流注入をしたところ、素子面内均一で明瞭な青色発光を示し、最高８ｃｄの発光出力を示した Through the above steps, a light emitting device on a full-wafer Mo conductive substrate having a structure in which the LED functional layer was bonded to the Mo conductive substrate via an adhesive layer was obtained. Although a slight amount of Ga metal remained on the surface of the light emitting element, since the Ga metal itself can be used as a semitransparent ohmic electrode of n-type GaN, the characteristics of the light emitting element were evaluated as they were. When a current of 20 mA was injected into an element having an electrode diameter of 200 μm using the Mo conductive substrate side as a positive electrode and the Ga metal side as a negative electrode, uniform and clear blue light emission was shown in the element surface, and a light emission output of up to 8 cd was shown.
実施例２
ｎ型のオーミック電極として、Ｇａ電極に替えて、網目状Ａｌ／Ｐｔ／Ｎｉ電極を用いたことを除いて、実施例１と同じ条件でフルウェハのＭｏ導電性基板上の発光素子を作製した。
まず、ＢＨＦ洗浄、研磨法により、窒化物半導体エピタキシャル結晶表面に残留しているＧａを除去、該表面の平坦化をした。研磨条件は、０．０５ＭＰａ、６０ｒｐｍ、１０分で、厚さ約０．２μｍ分を除去した。
次に、該表面に、粒径０．３７μｍ、１５ｗｔ％に希釈したコロイダルシリカ（扶桑化学工業（株）社製、商品名ＰＬ−２０）を、スピンコート法により塗布した。スピンコート条件は、２００ｒｐｍ、１０秒の間に、スラリー液下、スピンコートし、引き続き２５００ｒｐｍ、４０秒スピンコートした。
次に、リフトオフ法によりＡｌＰｔＮｉ電極パターンを形成した。ＡｌＰｔＮｉ電極を形成するために、電極が蒸着される該表面にある、コロイダルシリカに由来する微粒のシリカ粒子をバッファードフッ酸（ＢＨＦ）で除去した後、真空蒸着装置にてＡｌを２０００Å、引き続いてＰｔを５００Å、Ｎｉを８００Å蒸着し、リフトオフ法により電極パターンを形成した。
次に、ＩＣＰドライエッチング法により、網目状電極の開口部にあるコロイダルシリカに由来する微粒のシリカ粒子をマスクとしてエッチングした。これにより、微小突起状の窒化物半導体エピタキシャル結晶を形成することができる。ＩＣＰドライエッチングに用いたエッチングガスは、Ｃｌ2、ＣＨ2Ｃｌ2、Ａｒの混合ガスであり、ガス流量は各々２０、１０、４０ｓｃｃｍ、圧力０．８Ｐａ、ＩＣＰパワー２００Ｗ、バイアスパワー１００Ｗ、エッチング時間７分である。ＮｉはＩＣＰドライエッチングのマスクをして機能し、Ｎｉはエッチングされわずかに残留し、ＡｌＰｔは蒸着した分残留している。これらにより、網目状ＡｌＰｔＮｉ電極の開口部に高さ６００ｎｍ程度の微小突起状の窒化物半導体エピタキシャル結晶が形成された。
電極直径２００μｍ、網目電極幅２μｍ、網目電極ピッチ２５μｍ、電極パッド５０μｍ角、開口率８５％の素子に２０ｍＡの電流注入をしたところ、素子面内均一で明瞭な青色発光をし、最高１０ｃｄの輝度を示した。
Example 2
A light emitting device on a full-wafer Mo conductive substrate was fabricated under the same conditions as in Example 1 except that a mesh-like Al / Pt / Ni electrode was used as the n-type ohmic electrode instead of the Ga electrode.
First, Ga remaining on the nitride semiconductor epitaxial crystal surface was removed by BHF cleaning and polishing, and the surface was flattened. Polishing conditions were 0.05 MPa, 60 rpm, 10 minutes, and a thickness of about 0.2 μm was removed.
Next, colloidal silica (manufactured by Fuso Chemical Industry Co., Ltd., trade name PL-20) diluted to a particle size of 0.37 μm and 15 wt% was applied to the surface by a spin coating method. As spin coating conditions, spin coating was performed in a slurry solution at 200 rpm for 10 seconds, followed by spin coating at 2500 rpm for 40 seconds.
Next, an AlPtNi electrode pattern was formed by a lift-off method. In order to form an AlPtNi electrode, fine silica particles derived from colloidal silica on the surface on which the electrode is vapor-deposited are removed with buffered hydrofluoric acid (BHF). Then, Pt was deposited at 500 mm and Ni was deposited at 800 mm, and an electrode pattern was formed by a lift-off method.
Next, the fine silica particles derived from colloidal silica in the openings of the mesh electrode were etched by ICP dry etching using the mask. Thereby, a microprojection-like nitride semiconductor epitaxial crystal can be formed. The etching gas used for ICP dry etching is a mixed gas of Cl 2 , CH 2 Cl 2 , and Ar, and the gas flow rates are 20, 10, 40 sccm, pressure 0.8 Pa, ICP power 200 W, bias power 100 W, etching time, respectively. 7 minutes. Ni functions as a mask for ICP dry etching, Ni is etched and remains slightly, and AlPt remains as deposited. As a result, a microprojection-shaped nitride semiconductor epitaxial crystal having a height of about 600 nm was formed in the opening of the network AlPtNi electrode.
When a current of 20 mA was injected into an element having an electrode diameter of 200 μm, a mesh electrode width of 2 μm, a mesh electrode pitch of 25 μm, an electrode pad of 50 μm square, and an aperture ratio of 85%, uniform and clear blue light emission within the element surface was achieved, and a maximum luminance of 10 cd. showed that.
実施例３
導電性基板として、Ｍｏ製のものに替えて、大きさ２インチ径、厚さ１００μｍ、平均表面粗さ１２.２ｎｍの表面鏡面研磨したＷ製の導電性基板を用いたことを除いて、実施例１と同じ条件で貼り合せ基板を作製した。貼り合せ基板の反りを測定したところ、基板中央で１１３μｍであった。これを用いて、フルウェハのＷ導電性基板上の発光素子を作製した。電極直径２００μｍの素子に２０ｍＡの電流注入をしたところ、素子面内均一で明瞭な青色発光をし、最高６ｃｄの輝度を示した。
Example 3
Conducted except that a conductive substrate made of W with a mirror-polished surface having a 2 inch diameter, a thickness of 100 μm, and an average surface roughness of 12.2 nm was used instead of the Mo substrate. A bonded substrate was produced under the same conditions as in Example 1. When the warpage of the bonded substrate was measured, it was 113 μm at the center of the substrate. Using this, a light emitting device on a full-wafer W conductive substrate was produced. When a current of 20 mA was injected into an element having an electrode diameter of 200 μm, uniform and clear blue light emission was obtained in the element surface, and a maximum luminance of 6 cd was exhibited.
実施例４
導電性基板として、Ｍｏ製のものに替えて、大きさ２インチ径、厚さ１００μｍ、平均表面粗さ９.８ｎｍの表面鏡面研磨したＴａ製の導電性基板を用いたことを除いて、実施例１と同じ条件で貼り合せ基板を作製した。貼り合せ基板の反りを測定したところ、基板中央で２０μｍであった。これを用いて、フルウェハのＴａ導電性基板上の発光素子を作製した。電極直径２００μｍの素子に２０ｍＡの電流注入をしたところ、素子面内均一で明瞭な青色発光をし、最高４ｃｄの輝度を示した。
Example 4
Conducted except that a conductive substrate made of Ta having a surface mirror-polished with a 2 inch diameter, a thickness of 100 μm, and an average surface roughness of 9.8 nm was used as the conductive substrate instead of the Mo substrate. A bonded substrate was produced under the same conditions as in Example 1. When the warpage of the bonded substrate was measured, it was 20 μm at the center of the substrate. Using this, a light emitting device on a full-wafer Ta conductive substrate was produced. When a current of 20 mA was injected into an element having an electrode diameter of 200 μm, uniform and clear blue light emission was obtained in the element surface, and a maximum luminance of 4 cd was exhibited.
比較例１
導電性基板として、Ｍｏ製のものに替えて、大きさ２インチ径、厚さ１００μｍ、平均表面粗さ５.５ｎｍの鏡面研磨したＣｕ製の導電性基板を用いたことを除いて、実施例１と同じ条件で貼り合せ基板を作製した。しかしウェハ全体を十分な強度で貼り合せることができなかったため、ＬＥＤを作製することが不可能であった。ＣｕとＧａＮとの熱膨張係数差が大き過ぎるため、大きな反りが生じた後、導電性基板と化合物半導体機能層の間で剥離が生じてしまった。
Comparative Example 1
Example except that a conductive substrate made of Cu having a polished surface of 2 inches in diameter, a thickness of 100 μm, and an average surface roughness of 5.5 nm was used as the conductive substrate instead of the one made of Mo. A bonded substrate was produced under the same conditions as in 1. However, since the entire wafer could not be bonded with sufficient strength, it was impossible to produce an LED. Since the thermal expansion coefficient difference between Cu and GaN is too large, peeling occurred between the conductive substrate and the compound semiconductor functional layer after large warpage occurred.
比較例２
導電性基板として、Ｍｏ製のものに替えて、大きさ２インチ径、厚さ１０００μｍの鏡面研磨したＣｕ製の導電性基板を用いたことを除いて、実施例１と同じ条件で貼り合せ基板を作製した。しかしウェハ全体を十分な強度で貼り合せることができなかったため、ＬＥＤを作製することが不可能であった。大きな反りが生じた後、導電性基板と化合物半導体機能層の間で剥離が生じてしまった。
Comparative Example 2
As a conductive substrate, a bonded substrate was used under the same conditions as in Example 1 except that a Cu-polished substrate with a 2 inch diameter and a thickness of 1000 μm was used instead of the one made of Mo. Was made. However, since the entire wafer could not be bonded with sufficient strength, it was impossible to produce an LED. After a large warp occurred, peeling occurred between the conductive substrate and the compound semiconductor functional layer.
比較例３
導電性基板として、Ｍｏ製のものに替えて、大きさ２インチ径、厚さ１０００μｍ、平均表面粗さ２.７ｎｍの鏡面研磨したＡｌ製の導電性基板を用いたことを除いて、実施例１と同じ条件で貼り合せ基板を作製した。しかしウェハ全体を十分な強度で貼り合せることができなかったため、ＬＥＤを作製することが不可能であった。大きな反りが生じた後、導電性基板と化合物半導体機能層の間で剥離が生じてしまった。
Comparative Example 3
Example except that a conductive substrate made of mirror-polished Al having a size of 2 inches in diameter, a thickness of 1000 μm, and an average surface roughness of 2.7 nm was used instead of a substrate made of Mo. A bonded substrate was produced under the same conditions as in 1. However, since the entire wafer could not be bonded with sufficient strength, it was impossible to produce an LED. After a large warp occurred, peeling occurred between the conductive substrate and the compound semiconductor functional layer.
Claims (14)
（２）積層体１のＧａＮ層を含む化合物半導体機能層上に、電極、密着性向上層、接着層をこの順に積層して積層体２を得る工程、
（３）積層体２の接着層と、別に準備した導電性基板に密着性向上層を積層して得られる積層体３の密着性向上層とを貼り合せて積層体５を得る工程、または積層体２の接着層と、別に準備した導電性基板に密着性向上層、接着層を積層して得られる積層体４の接着層とを貼り合せて積層体５を得る工程、
（４）前記の（３）の工程で得られた積層体５から成長基板を除去して積層体６を得る工程、
（５）前記の（４）の工程で得られた積層体６を素子分割する工程
を、この順で有することを特徴とする請求項１〜１０のいずれかに記載の化合物半導体発光素子の製造方法。 (1) A step of obtaining a laminate 1 by laminating a compound semiconductor functional layer including a GaN layer on a growth substrate,
(2) A step of obtaining a laminate 2 by laminating an electrode, an adhesion improving layer, and an adhesive layer in this order on the compound semiconductor functional layer including the GaN layer of the laminate 1;
(3) The step of obtaining the laminate 5 by bonding the adhesive layer of the laminate 2 and the adhesion improving layer of the laminate 3 obtained by laminating the adhesion improving layer on a separately prepared conductive substrate, or lamination Bonding the adhesive layer of the body 2 and the adhesive layer of the laminate 4 obtained by laminating the adhesion improving layer and the adhesive layer to a separately prepared conductive substrate to obtain the laminate 5;
(4) A step of removing the growth substrate from the laminate 5 obtained in the step (3) to obtain a laminate 6;
(5) The method for producing a compound semiconductor light-emitting device according to any one of claims 1 to 10, further comprising a step of dividing the laminate 6 obtained in the step (4) in this order. Method.
（２）積層体１のＧａＮ層を含む化合物半導体機能層に素子分離溝を作製し、分離された化合物半導体機能層の上に、電極、密着性向上層、接着層をこの順に積層して積層体７を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極を積層し、該化合物半導体機能層と電極とに素子分離溝を作製し、分離された電極の上に、密着性向上層、接着層をこの順に積層して積層体８を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極、密着性向上層をこの順に積層し、該化合物半導体機能層と電極と密着性向上層とに素子分離溝を作製し、分離された密着性向上層の上に、接着層を積層して積層体９を得る工程、
または積層体１のＧａＮ層を含む化合物半導体機能層の上に電極、密着性向上層、接着層をこの順に積層し、該化合物半導体機能層、密着性向上層、接着層に素子分離溝を作製して積層体１０を得る工程、
（３）積層体７、積層体８、積層体９、積層体１０のいずれかの接着層と、
別に準備した導電性基板に密着性向上層を積層して得られる積層体３の密着性向上層とを貼り合せて積層体１１を得る工程、または積層体７、積層体８、積層体９、積層体１０のいずれかの接着層と、別に準備した導電性基板に密着性向上層、接着層を積層して得られる積層体４の接着層とを貼り合せて積層体１１を得る工程、
（４）前記の（３）の工程で得られた積層体１１から成長基板を除去して積層体１２を得る工程、
（５）前記の（２）の工程で作製された素子分離溝に合わせて、積層体１２を切断する工程を、この順で有することを特徴とする請求項１〜１０のいずれかに記載の化合物半導体発光素子の製造方法。 (1) A step of obtaining a laminate 1 by laminating a compound semiconductor functional layer including a GaN layer on a growth substrate,
(2) An element isolation groove is formed in the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the separated compound semiconductor functional layer. Obtaining a body 7;
Alternatively, an electrode is stacked on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, an element isolation groove is formed in the compound semiconductor functional layer and the electrode, and an adhesion improving layer is formed on the separated electrode. A step of obtaining a laminate 8 by laminating adhesive layers in this order;
Alternatively, an electrode and an adhesion improving layer are laminated in this order on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an element isolation groove is formed in the compound semiconductor functional layer, the electrode, and the adhesion improving layer, and separated. A step of obtaining a laminate 9 by laminating an adhesive layer on the adhesion improving layer formed;
Alternatively, an electrode, an adhesion improving layer, and an adhesive layer are laminated in this order on the compound semiconductor functional layer including the GaN layer of the multilayer body 1, and an element isolation groove is formed in the compound semiconductor functional layer, the adhesion improving layer, and the adhesive layer. And obtaining the laminate 10,
(3) the adhesive layer of any one of the laminate 7, the laminate 8, the laminate 9, and the laminate 10,
A step of obtaining a laminate 11 by laminating an adhesion improvement layer of a laminate 3 obtained by laminating an adhesion improvement layer on a separately prepared conductive substrate, or a laminate 7, a laminate 8, a laminate 9, A step of obtaining a laminate 11 by bonding any adhesive layer of the laminate 10 and an adhesive layer of a laminate 4 obtained by laminating an adhesion improving layer and an adhesive layer on a separately prepared conductive substrate;
(4) A step of removing the growth substrate from the laminate 11 obtained in the step (3) to obtain a laminate 12;
(5) It has the process of cut | disconnecting the laminated body 12 according to the element isolation groove produced at the process of said (2) in this order, The Claim 1 characterized by the above-mentioned. A method for producing a compound semiconductor light emitting device.
The method for producing a compound semiconductor light-emitting element according to claim 1, wherein the metal material is mirror-polished.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2009099675A (en) * | 2007-10-15 | 2009-05-07 | Showa Denko Kk | Method of manufacturing light emitting diode, light emitting diode, and lamp |
| JP2011187556A (en) * | 2010-03-05 | 2011-09-22 | Toshiba Corp | Semiconductor light-emitting element, semiconductor light-emitting device, and method for manufacturing the same |
| JP2011525707A (en) * | 2008-11-07 | 2011-09-22 | ▲東▼莞市中▲か▼半▲導▼体科技有限公司 | Non-destructive lift-off method of GaN (gallium nitride) and sapphire substrate using solid-state laser |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2009099675A (en) * | 2007-10-15 | 2009-05-07 | Showa Denko Kk | Method of manufacturing light emitting diode, light emitting diode, and lamp |
| JP2011525707A (en) * | 2008-11-07 | 2011-09-22 | ▲東▼莞市中▲か▼半▲導▼体科技有限公司 | Non-destructive lift-off method of GaN (gallium nitride) and sapphire substrate using solid-state laser |
| JP2011187556A (en) * | 2010-03-05 | 2011-09-22 | Toshiba Corp | Semiconductor light-emitting element, semiconductor light-emitting device, and method for manufacturing the same |
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