CN101075726A

CN101075726A - Method for producing semiconductor microdisk laser

Info

Publication number: CN101075726A
Application number: CN 200610011924
Authority: CN
Inventors: 罗贤树; 黄永箴; 陈沁�
Original assignee: Institute of Semiconductors of CAS
Current assignee: Institute of Semiconductors of CAS
Priority date: 2006-05-18
Filing date: 2006-05-18
Publication date: 2007-11-21

Abstract

This is a process method for semi-conducting minidisk leaser including the following steps: 1) coating photo etching gel on the surface of a clean disk; 2) make pattern on the photo etching gel through photo etching and developing; 3) non-selective wet etch or dry etch with optimized etching depth according to mold frequency and quality index.

Description

Make the method for semiconductor microdisk laser

Technical field

The invention belongs to technical field of semiconductors, be meant a kind of method of making semiconductor microdisk laser especially.

Background technology

Semiconductor microdisk laser is the new laser of a kind of small size, low threshold value, low-power consumption.Its resonant cavity is different with common Fabry-Perot chamber, but a disk-like structure.When pattern is propagated, on plate edge and air interface, carry out the Whispering-gallery-mode that total reflection obtains high-quality-factor in this resonant cavity.Therefore, it is a kind ofly to utilize total reflection to form the laser that special Whispering-gallery-mode carries out work.

The semiconductor microdisk laser manufacture craft is simple, only needs to obtain little disk shape by common etching technics on active material and gets final product.Experimental study through more than 10 years, present microdisk laser adopts two kinds of typical structures more, a kind of is cylindrical-shaped structure (A.F.J.Levi, etc., Room-temperature lasing actionin InGaP/InGaAs microcylinder laser diodes, Appl.Phys.Lett.62, pp.2021-2023 (1993)), form a cylinder by etching, active layer wherein, the bound preparative layer all has identical radius, and vertically the light field restriction is mainly realized by the bound preparative layer of low-refraction; Another kind is the structure (S.L.McCall that thin polygon post supports little dish, etc., Whispering-gallery mode microdisk lasers, Appl.Phys.Lett.60, pp289-291 (1992)), form cylindrical-shaped structure by etching earlier, by selective corrosion lower limit layer is corroded into buttress shaft as support then, vertical light restriction of this structure is realized by upper limiting layer and following layer of air.Certainly, upper limiting layer also can be an air, promptly directly active layer is contacted with air.But no matter which kind of structure all need solve a problem, that is exactly how to select suitable etching depth, thereby optimizes laser performance.The objective of the invention is at this situation, investigate the variation of pattern wavelength and quality factor, realize the optimization of etching depth, thereby reach the purpose of optimizing the semiconductor microdisk laser performance by changing etching depth.

Summary of the invention

The objective of the invention is to, a kind of method of making semiconductor microdisk laser is provided, it is by controlling different etching depths to the excitation wavelength of microdisk laser and the influence of pattern quality factor, thereby realize optimization, the high-performance microdisk laser that obtains having wavelength stabilization and low threshold value to etching depth.

The objective of the invention is to realize by following scheme:

A kind of method of making semiconductor microdisk laser of the present invention is characterized in that, comprises the steps:

(1) coats photoresist on the structure sheet surface that cleans up;

(2) by photoetching and developing technique, with required figure transfer to photoresist;

(3) by non-selective wet etching or dry etching, variation relation according to mode frequency and quality factor and etching depth, select the etching depth of optimization, etching depth is controlled, obtain required cylindrical microdisk laser by accurate control etch period.

Wherein the structure sheet comprises lower limit layer, active layer and the upper limiting layer of substrate and growth successively.

Wherein active layer is a semiconductor strain body material.

Wherein active layer is the semiconductor strain quantum-well materials.

Description of drawings

For purpose of the present invention better is described, describe content of the present invention in detail below in conjunction with drawings and Examples, wherein:

Fig. 1 is the structural representation of the cylindrical microdisk laser of semiconductor.

Fig. 2 is the mode frequency of the cylindrical microdisk laser of semiconductor and the quality factor change curve with etching depth H.

Fig. 3 is the manufacture craft flow process of the cylindrical microdisk laser of semiconductor;

Fig. 3 (a) is the structural representation of complete structure sheet;

Fig. 3 (b) coats the schematic diagram of photoresist 500 for the structure sheet surface of cleaning in process;

Fig. 3 (c) is the figure transfer process, after photoetching and developing, and the schematic diagram of required figure transfer to the photoresist 500;

Fig. 3 (d) is the cylindrical little dish structural representation that forms after over etching;

Fig. 3 (e) is for removing the structural representation of the cylindrical microdisk laser that obtains after the photoresist.

Embodiment

See also Fig. 1 and cooperate and consult Fig. 3, a kind of method of making semiconductor microdisk laser of the present invention comprises the steps:

(1) coats photoresist 500 on the structure sheet surface that cleans up, this structure sheet comprises lower limit layer 301, active layer 200 and the upper limiting layer 300 of substrate 105 and growth successively, and this active layer 200 is semiconductor strain body material or is the semiconductor strain quantum-well materials;

(2) by photoetching and developing technique, with required figure transfer to photoresist 500;

(3) by non-selective wet etching or dry etching, variation relation according to mode frequency and quality factor and etching depth, select the etching depth of optimization, etching depth is controlled, obtain required cylindrical microdisk laser 600 by accurate control etch period.

Please consult again shown in Figure 1, the cylindrical microdisk laser 600 of semiconductor, the active layer 200 of laser is disc response body material or strained quantum well active layer 200, this active layer 200 is enough thin so that only have single longitudinal mode in this structure.Active layer is covered by limiting

layer

300 and 301 up and down, and bound

preparative layer

300 and 301 can be a same material, also can be different materials.Upper limiting layer 300 can also be an air layer, and promptly active layer 200 directly contacts with air.Substrate 105 is a device substrate, device substrate 105 should with lower limit layer 301 lattice match, also can adopt identical materials with lower limit layer 301.The target H of institute represents etching depth among the figure, is the thickness sum of the lower limit layer 301 of upper limiting layer 300, active layer 200 and etching.

Fig. 2 is the mode frequency of the cylindrical microdisk laser of semiconductor and the quality factor change curve with etching depth H.This result carries out The results of numerical simulation to the structure among Fig. 1, wherein selection of parameter is as follows: air layer/upper limiting layer 300/ active layer 200/ lower limit layer 301/ substrate 105 each layer refraction index profile are 1.0/3.17/3.4/3.17/3.17, corresponding to the Air/InP/InGaAsP/InP/InP material system, wherein here we to select bound preparative layer and substrate be identical materials.Active layer 200 thickness are 0.2 micron, and this thickness can guarantee only to exist single longitudinal mode.The thickness of upper limiting layer 300 and substrate 105 is respectively 1.5 microns and 6.0 microns, and remains unchanged in computational process.We can reach the purpose that changes etching depth by the thickness that changes lower limit layer 31.As seen from Figure 2, etching depth is 1.7 microns, and this moment, lower limit layer thickness was zero, and when promptly active layer directly contacted with substrate, light field caused the pattern quality factor very low in that vertically leakage is very severe, has only about 100.This moment, the zlasing mode frequency was 196.7THz.Along with the increase of etching depth, the pattern quality factor constantly increases, and mode frequency reduces gradually.When etching depth reached 3.25 microns, quality factor was increased to 2223, had reached its first peak value, and corresponding mode frequency is 196.65.After this, pattern quality factor and frequency all begin to vibrate, and the maximum of pattern quality factor and maximum remain on about 3000 and 1500, and oscillation amplitude is about 1500; And the oscillation amplitude of frequency is 0.05THz, remains stationary value substantially.But noticeable phenomenon is, the orientation of oscillation of mode frequency and quality factor is just opposite, and promptly big quality factor is corresponding to the low mode frequency, and little quality factor is corresponding to the height mode frequency.This point from etching depth less than can clearly observing on 3.25 microns the curve.

Fig. 3 is the manufacture craft flow process of the cylindrical microdisk laser of semiconductor, and wherein Fig. 3 (a) is complete structure sheet, comprises substrate 105, upper limiting layer 300 and lower limit layer 301 and response body material or strained quantum well active layer 200.General and the lower limit layer of substrate 105 has the identical materials structure.Fig. 3 (b)-(e) is the cylindric microdisk laser that forms later on by common photoetching and etching, and etching can adopt traditional non-selective wet etching, also can adopt dry etching, decides on necessary requirement.Analog result according to Fig. 2 gained, we can select suitable etching depth, by reasonable control etch period etching depth are controlled, thereby are obtained the zlasing mode of high-quality-factor, reduce the threshold current of laser, reach the purpose of optimizing laser performance.

Remove the photoresist 500 of the superiors at last.

The front is that example describes the present invention with the InGaAsP material, but is not construed as limiting the invention.

Disclosed, be a kind of of preferred embodiment, the change of every part or modification and come from technological thought of the present invention and be have the knack of this technology the people was easy to know by inference, all do not take off patent right scope of the present invention.

Claims

1, a kind of method of making semiconductor microdisk laser is characterized in that, comprises the steps:

(1) coats photoresist on the structure sheet surface that cleans up;

(2) by photoetching and developing technique, with required figure transfer to photoresist:

2, the method for making semiconductor microdisk laser according to claim 1 is characterized in that, wherein the structure sheet comprises lower limit layer, active layer and the upper limiting layer of substrate and growth successively.

3, the method for making semiconductor microdisk laser according to claim 2 is characterized in that, wherein active layer is a semiconductor strain body material.

4, the method for making semiconductor microdisk laser according to claim 2 is characterized in that, wherein active layer is the semiconductor strain quantum-well materials.