CN1155120C

CN1155120C - Process for praparing core of LED on sapphire substrate

Info

Publication number: CN1155120C
Application number: CNB011295163A
Authority: CN
Inventors: 辉杨; 杨辉; 张书明
Original assignee: China Fangda Group Co Ltd
Current assignee: Shenzhen Fangda Guoke Optoelectronic Technology Co., Ltd.
Priority date: 2001-06-22
Filing date: 2001-06-22
Publication date: 2004-06-23
Anticipated expiration: 2021-06-22
Also published as: CN1393939A

Abstract

The present invention provides a method for forming a tube core of a semiconductor light emitting diode on a sapphire substrate. An III-V gallium nitride base compound semiconductor and the figure of the tube core of the semiconductor light emitting diode of a quantum well structure thereof are designed into a parallelogram or diamond structure adjacent to two edge cleavage surfaces of the sapphire substrate, and included angles are 120 degrees or 60 degrees. A tube core dividing passage is in the cleavage direction of the sapphire substrate, and the sapphire substrate is ground to be thin and is cut along the dividing passage to form the tube core.

Description

On Sapphire Substrate, form the method for semiconductor light-emitting-diode tube core

Technical field

The invention belongs to technical field of semiconductors, be meant a kind of method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core especially.

Background technology

III-V family gallium nitride (GaN) based compound semiconductor and quantum well structure light-emitting diode (LED) thereof have advantages such as high reliability, high efficiency, response fast, long-life, total solidsization, volume are little, in large scale display, the indication of traffic lights information, has huge application market especially for white-light illuminating.But, because Sapphire Substrate does not have orthogonal cleavage surface, and hardness is big, be difficult to cleavage and be divided into tube core with square structure, cut apart at the bottom of the rate of finished products, this gives the cost that reduces the III-V GaN of family based compound semiconductor and quantum well structure light-emitting diode (LED) thereof, expands application market and has brought obstacle.

The present invention's method forming the semiconductor light-emitting-diode tube core on the Sapphire Substrate in the past is: epitaxial growth light-emitting diode structure on Sapphire Substrate, the N electrode and the P electrode of preparation diode are divided into singulated dies with patterning method or scribing method along the direction of cutting apart of the tube core of the square structure size that designs then.Because the cleavage direction of Sapphire Substrate is not vertical, when a segmentation side direction of tube core along Sapphire Substrate cleavage direction, another segmentation side will no longer be a Sapphire Substrate cleavage direction, when cutting or draw when splitting, produce along cutting or scribing direction and serious to collapse the limit or along non-cutting or scribing direction cracking, cause tube core to damage, reduced rate of finished products, for head it off, the size (greater than 60 μ m) that general employing increasing is cut apart and the method for positive and negative cutting twice have prolonged clipping time like this, and have increased the consumption of cutter, make the productive rate of product little, increased the cost of product.

Summary of the invention

The object of the present invention is to provide a kind of method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core, when can overcoming in light-emitting diode manufacture process scribing or cutting, it produces the problem that collapses limit or cracking along the non-direction of cutting apart, can make the tube core of scribing or cutting neat, the size of cutting apart can be decreased to 40 μ m, improve the productive rate and the rate of finished products of product, reduced product cost.

A kind of method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core of the present invention, it is characterized in that, III-V family gallium nitride-based compound semiconductor and quantum well structure LED core graphic designs thereof are become adjacent two edge Sapphire Substrate cleavage surfaces, angle is the parallelogram or the diamond structure of 120 degree or 60 degree, tube core is cut apart the cleavage direction of direction along Sapphire Substrate, and with Sapphire Substrate wear down to 70 between 250 microns, cut apart the direction cutting from the back side along tube core, form tube core.

The size of cutting apart is less than 60 μ m, and minimum is 40 μ m.

With dry etching or wet etching, photoetching, peel off, the P electrode and the N electrode of evaporation or fabrication techniques diodes such as sputter coating, alloy and form tube core and cut apart, then with Sapphire Substrate from the back side with abrasive method or ion milling technology attenuate and be polished to 70 μ m to the 250 μ m, the evenness that makes sample behind the attenuate is between ± 5 μ m, cut apart the direction cutting then from the sample back side along tube core, form tube core.

Described cutting is that sample is pasted on the blue film, and the front is close to blue film, with vacuum suction or other ways sample is fixed on cutting or the scribing workbench, then from the back side with cutting or the method for scribing is cut apart direction along tube core and cut apart tube core; When cutting apart tube core with cutting method, can adopt the method for drawing saturating sample that tube core is directly separated, perhaps the degree of depth of cutting groove is 1/2 to 1/4 of a thickness of sample, each depth of cut is controlled at 5 μ m to 10 μ m, roll gently from blue film with other thin rods such as the metal of diameter 1mm to 20mm, wooden or plastics then, tube core is separated.

During with the way of scribing, the pressure of control cutter to cutting apart reaches between 3 μ m to the 10 μ m cutting groove degree of depth, rolls gently from blue film with other thin rods such as the metal of diameter 1mm to 20mm, wooden or plastics then, and tube core is separated.

Description of drawings

For further specifying content of the present invention, below in conjunction with embodiment the present invention is done a detailed description, wherein:

Fig. 1 is the present invention forms tube core on Sapphire Substrate a figure;

Fig. 2 is a schematic diagram of cutting apart tube core with cutting method of the present invention;

Fig. 3 is tube core is cut apart in the present invention with dicing method a schematic diagram.

Embodiment

At first see also shown in Figure 1, characteristics according to Sapphire Substrate, the GaN of III-V family based compound semiconductor and quantum well structure light-emitting diode (LED) tube core graphic designs thereof are become the cleavage direction of adjacent two edge Sapphire Substrate, angle is the parallelogram or the diamond structure of 120 degree (or 60 degree), cuts apart 10 sizes, 40 μ m.

With epitaxial growth in the III-V of Sapphire Substrate 20 GaN of family based compound semiconductor N type layer 21 and P type layer 22 and quantum well structure light-emitting diode (LED) structure thereof with dry etching or wet etching, photoetching, peel off (Lift-off), evaporation or sputter coating, the P electrode of fabrication techniques diodes such as alloy and N electrode and formation cut apart 10, then Sapphire Substrate 20 is thinned to them between 70 μ m to 250 μ m from the back side with abrasive method or ion milling technology, and the substrate behind the attenuate is polished, the evenness that makes the sample behind the attenuate cuts apart 10 and the figure of tube core what microscopically can be seen the sample front clearly from the back side of sample between ± 5 μ m.

Sample is pasted on the blue film again, and blue film is close in the front, with vacuum suction or additive method sample is adsorbed on cutting or the scribing workbench, cuts apart 10 directions from the back side along tube core with the method for cutting (dicing) or scribing (scribe) then and cut apart tube core (consulting Fig. 2, shown in Figure 3).With cutting (dicing) when method is cut apart tube core, can adopt the method for drawing saturating sample that tube core is directly separated, perhaps the degree of depth of cutting groove 23 is 1/2 to 1/4 of a thickness of sample, each depth of cut is controlled at 5 μ m to 10 μ m, one roll gently from blue film with other thin rods such as the metal of diameter 1mm to 20mm, wooden or plastics then, can easily tube core be separated.

During with the way of scribing, the pressure of control cutter to cutting apart, cutting groove 23 degree of depth are reached between 3 μ m to the 10 μ m, roll gently from blue film with other thin rods such as the metal of diameter 1mm to 20mm, wooden or plastics then, can easily tube core be separated.

Specific embodiment:

1. the sample that will prepare electrode is from thinning back side and be polished to 150 μ m, cuts apart 10 and is of a size of 40 μ m, cuts apart tube core with the method for scribing, and rate of finished products is more than 90%, and when cutting groove 23 degree of depth reached 10 μ m, it was easier to cut apart; Cut apart tube core with cutting method, the depth of cut 10 μ m, cutting groove 23 penetraction depths 40 μ m to 60 μ m, rate of finished products also can reach more than 90%.When reducing the depth of cut to 5 μ m, segmentation effect is better, and is more neat.Cut apart schematic diagram such as Fig. 2 and Fig. 3.

2. the sample that will prepare electrode is from thinning back side and be polished to 100 μ m, cuts apart 10 and is of a size of 40 μ m, cuts apart tube core with the method for scribing, and rate of finished products is more than 96%, and when cutting groove 23 degree of depth reached 10 μ m, it was easier to cut apart; Cut apart tube core with cutting method, the depth of cut 10 μ m, cutting groove 23 penetraction depths 25 μ m to 40 μ m, rate of finished products can reach more than 95%.When reducing the depth of cut to 5 μ m, segmentation effect is better, and is more neat.

3. the sample that will prepare electrode is from thinning back side and be polished to 80 μ m, cuts apart 10 and is of a size of 40 μ m, cuts apart tube core with the method for scribing, and rate of finished products is more than 99%, and when cutting groove 23 degree of depth reached 10 μ m, it was easier to cut apart; Cut apart tube core with cutting method, the depth of cut 10 μ m, cutting groove 23 penetraction depths 20 μ m to 30 μ m, rate of finished products can reach more than 99%.When reducing the depth of cut to 5 μ m, segmentation effect is better, and is more neat.

The present invention has utilized the characteristics of Sapphire Substrate, adopt its cleavage direction to cut apart direction as tube core, before having solved square tube core when cutting apart tube core along non-cut apart to produce collapse the limit or cut apart the direction cracking and damage the shortcoming that tube core influences the finished product rate along non-, reduced the size in stroke road, can improve the productive rate and the rate of finished products of product, reduce the cost of product.

Claims

1. method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core, it is characterized in that, III-V family gallium nitride-based compound semiconductor and quantum well structure LED core graphic designs thereof are become adjacent two edge Sapphire Substrate cleavage surfaces, angle is the parallelogram or the diamond structure of 120 degree or 60 degree, tube core is cut apart the cleavage direction of direction along Sapphire Substrate, and with Sapphire Substrate wear down to 70 between 250 microns, cut apart the direction cutting from the back side along tube core, form tube core.

2. the method that forms the semiconductor light-emitting-diode tube core on Sapphire Substrate according to claim 1 is characterized in that the size of cutting apart is less than 60 μ m, and minimum is 40 μ m.

3. the method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core according to claim 1, it is characterized in that, with dry etching or wet etching, photoetching, peel off, the P electrode and the N electrode of evaporation or fabrication techniques diodes such as sputter coating, alloy and form tube core and cut apart, then with Sapphire Substrate from the back side with abrasive method or ion milling technology attenuate and be polished to 70 μ m to the 250 μ m, the evenness that makes sample behind the attenuate is between ± 5 μ m, cut apart the direction cutting then from the sample back side along tube core, form tube core.

4. the method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core according to claim 3, it is characterized in that, described cutting is that sample is pasted on the blue film, and blue film is close in the front, with vacuum suction or other ways sample is fixed on cutting or the scribing workbench, cuts apart direction with the method for cutting or scribing along tube core from the back side then and cut apart tube core; When cutting apart tube core with cutting method, can adopt the method for drawing saturating sample that tube core is directly separated, perhaps the degree of depth of cutting groove is 1/2 to 1/4 of a thickness of sample, each depth of cut is controlled at 5 μ m to 10 μ m, roll gently from blue film with other thin rods such as the metal of diameter 1mm to 20mm, wooden or plastics then, tube core is separated.

5. the method that on Sapphire Substrate, forms the semiconductor light-emitting-diode tube core according to claim 4, it is characterized in that, during with the way of scribing, the pressure of control cutter to cutting apart, the cutting groove degree of depth is reached between 3 μ m to the 10 μ m, roll gently from blue film with other thin rods such as the metal of diameter 1mm to 20mm, wooden or plastics then, tube core is separated.