JPS6019155B2 - Manufacturing method of semiconductor issuing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor light emitting device, and in particular, an object of the present invention is to provide an improved manufacturing method in which a green light emitting element used in the light emitting device has high luminous efficiency.

Green light emission exhibits high luminous efficiency when nitrogen atoms are added as emission centers to replace the lattice positions of phosphorus atoms constituting the semiconductor crystal. Alternatively, those grown by a vapor phase epitaxial growth method are used.

Recently, there has been a great demand for green light-emitting devices, and there is an extremely strong demand for devices with higher luminous efficiency. G
In order to improve the efficiency of the ap green light emitting device, it is important to introduce a large amount of nitrogen, which is the luminescent center, into the light emitting region and to increase the number of minority carriers injected into the light emitting region.

In the liquid phase growth method for obtaining a secondary green light emitting device, hydrogen is used as an atmospheric gas, and ammonia (NH3) is used as a dopant when doping nitrogen as a luminescent center.
) gas is used. That is, for example, n-type Gap
An n-layer is grown on the substrate by contacting it with a Gap solution while flowing NH3 gas at around 100,000 in a hydrogen atmosphere.
A p-layer is then grown on top of this to form a p-n junction. However, in this method, hydrogen and NH3 react and nitrogen escapes, and a large amount of nitrogen is not introduced into the GaP crystal, which has the disadvantage of low luminous efficiency as a green light-emitting device. . In order to eliminate these drawbacks, this invention improves the combination of boat material and atmospheric gas, controls the impurity profile at the pn junction, increases the injection efficiency, and at the same time significantly increases the luminescent center concentration. The present invention provides a method for manufacturing a semiconductor light-emitting device that improves luminous efficiency.

In other words, a growth device that combines carbon and quartz is used, hydrogen is used as an atmospheric gas when growing an n-layer on an n-type Gap substrate, silicon is introduced as a donor to keep the profile flat, and the n-layer is grown. After that, change the atmospheric gas to an inert gas such as argon, and at the same time flow a nitrogen gas to create a light-emitting region doped with a large amount of nitrogen.
It is characterized by growing layers to obtain a green light-emitting element with high luminous efficiency. An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show the light emitting element forming process. In the growth apparatus used in this process, reference numeral 1 denotes a boat body made of carbon, and a recess 2 for holding the GaP substrate is provided. A slidable solution reservoir 3 placed on this body 1
The main body is made of carbon, and the inside is lined with quartz 4. Further, a quartz plate 6 is placed on the bottom surface of the recess 2. In order to manufacture a light emitting device made of a Gap substrate using such a growth apparatus, as shown in FIG.
A solution 7 is put into the solution reservoir 3, and the solution 7 is poured onto the boat body in front of the recess, and then inserted into a reactor (not shown).

Hydrogen is flowed as an atmospheric gas at a flow rate of 501/ground. When the temperature is increased and reaches a predetermined temperature, for example 100p,
The solution reservoir is operated from outside the furnace and slid in the direction of the arrow to place it on the substrate as shown in FIG. 2, and the solution 8 is evenly applied to the substrate with a thickness of 2. Next, slide the solution reservoir further in the direction of the arrow to bring it into the state shown in FIG. 3 so that it does not cover the substrate.
The three powders are held in this state to partially dissolve the substrate.
Next, it is gradually cooled to 970° C. to grow an n-layer on the Gap substrate. The donor at this time is silicon liberated by the reaction of quartz with hydrogen. When the growth of the n-layer is completed in this manner, the atmospheric gas is changed to argon and flowed at a flow rate of 101/Hr, and at the same time, an N ratio gas for introducing nitrogen is flowed at a flow rate of 0.9/min. 6 in this state
After being held for 0 minutes, it is gradually cooled down again to grow a nitrogen-doped p layer. To explain in more detail, in an argon atmosphere, Si in the donor reacts with a portion of N& to form nitrides, so the introduction of NH3 lowers the donor concentration, and carbon, which was previously a residual acceptor, becomes an acceptor. A p-layer is formed. That is, carbon is introduced into the acceptor in an argon atmosphere. When the temperature reaches 93,000, the temperature is stopped again and held for 60 minutes, and zinc vapor is sent to make the solution highly concentrated p-type. Cooling is started again and the second p-type
A layer is grown on the first p-layer.

When it reaches 900 0, only flow argon and stop everything else.
Cool to room temperature. The GaP substrate on which the n-layer and p-layer have been grown in this manner is taken out. Cleavage a part of this substrate,
When the thickness of the grown layer was measured by etching the separation surface, the thickness of the n layer was 25 Å, the lp layer was 20 Å thick, and the first layer was 30 Å thick.

In addition, when the impurity concentration profile was measured using the Schottky method, the n layer was flat at 1 x 1 and 7, the lp layer was at 3 x 1 and 6, and the first layer was at 1 x 1 and 8. As shown in the figure. The vertical axis represents impurity concentration. Next, an Au alloy was deposited on this substrate as a p-type electrode and an Au alloy as an n-type electrode, and the pellet was made into a pellet having a diameter of 0.3 willow angle to measure luminous efficiency.

It showed a high efficiency of 0.25% (lf: divalent A) as an average value. Further, the variation was within 20%. Compared to the efficiency of conventional ones, which is 0.05 to 0.1%,
The device according to this invention has significantly higher luminous efficiency and has significantly improved characteristics. Furthermore, the boat used in the growth apparatus was made larger, the number of Gap substrates stacked was increased, and 10 Gap substrates were placed on the boat body, and the luminous efficiency was measured using pellets as described above.

In this case, the luminous efficiency was as high as 0.22 to 0.35%, and the variation was within 30%, indicating that high-performance green light-emitting elements could be mass-produced. As described above, the method of the present invention uses a liquid phase growth apparatus formed by combining carbon and quartz, so when growing an n-layer on a gap substrate, silicon can be efficiently introduced in a hydrogen atmosphere and the blob film can be grown. When the first p-layer is grown on top of the n-layer, a large amount of nitrogen is introduced by flowing N gas in an inert gas atmosphere such as argon, and this region becomes a light-emitting region. The acceptor concentration is controlled to be low, and a high concentration p layer is grown on top of this layer to obtain a green light emitting device with the excellent characteristics described above.

A green light-emitting semiconductor light-emitting device using such a mass-produced light-emitting element with good characteristics has high luminous efficiency and is industrially useful. The above is an explanation of the case where the luminescent center is introduced into the first p-layer, but there is a case where nitrogen is partially introduced into the n-layer immediately before it is converted into a p-type layer by the reaction between Si and NH3. However, it is natural that such a structure does not impair the effectiveness of the present invention and does not go against the spirit of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 are cross-sectional views showing an overview of the steps for obtaining the light emitting device of the present invention, and FIG. 4 is a curve diagram showing the impurity concentration of each layer of the light emitting device of the present invention.

1...Boat body, 2...Recessed part of boat body,
3...Solution reservoir, 5...Quartz plate with a groove in the recess, 6...Gap substrate, 4...Quartz tube for solution reservoir, 7... ...Solution in the solution reservoir, 8...
...Solution on the substrate.

Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. An n-layer without adding a luminescent center on an n-type GaP substrate using a liquid phase growth apparatus equipped with a boat body and a solution reservoir;
a first p-layer doped with a luminescent center adjacent to the n-layer;
A second p-layer is sequentially grown on this first p-layer.
In manufacturing a semiconductor light emitting device using a green light emitting element of P, the atmospheric gas during the growth of the n layer is hydrogen, and the atmospheric gas during the growth of at least the first p layer is an inert gas. A method for manufacturing a semiconductor light emitting device that emits light. 2. A method for manufacturing a semiconductor light emitting device according to claim 1, characterized in that the liquid phase growth device is formed by combining quartz and carbon, and the solution and the substrate are brought into contact with the surface formed of quartz. .