Summary of the invention
The present invention aims to provide a kind of MEMS electrically controlled dynamic gain equalizer chip production method.
Technical scheme of the present invention is that this preparation method comprises 14 technological operation steps: prepare first silicon chip 0 and second silicon chip 1; Silicon dioxide thin film growth; Deposit first polysilicon layer 4 and second polysilicon layer 4 '; Etching off second polysilicon layer 4 '; Remove the first positive glue 5; Deposit first silicon nitride film 6 and second silicon nitride film 6 '; Deposit the 3rd polysilicon layer 7 and the 4th polysilicon layer 7 '; Etching off the 4th polysilicon layer 7 '; The preparation fiber orientation groove corrosion mouth 8 and the first electrode corrosion mouth 9, the second electrode corrosion mouth 9 '; Deposit silicon dioxide support arm 10; Preparation complex optical film F-P cavity 11 and electrode hole 12; The high reflective film 13 of sputter alloy aluminum; Bonding; Preparation fiber orientation groove 14 gets MEMS electrically controlled dynamic gain equalizer chip.
Now be described with reference to the accompanying drawings technical scheme of the present invention.A kind of MEMS electrically controlled dynamic gain equalizer chip production method is characterized in that operating procedure:
The first step prepares first silicon chip 0 and second silicon chip 1
First silicon chip 0 adopts n type<100〉crystal orientation, second silicon chip 1 crystal orientation to choose wantonly, and the thickness of first silicon chip 0 and second silicon chip 1 is 540 μ m ± 5 μ m, and resistivity is 10 Ω cm;
The second one-step growth silica membrane
Alternately adopting the dry-oxygen oxidation and the wet-oxygen oxidation technology of thermal oxidation process is first silica membrane 2, second silica membrane 2 ' and the 3rd silica membrane 3, the 4th silica membrane 3 ' of 530 ± 50nm at first silicon chip 0 and second silicon chip, 1 two-sided equal growth thickness respectively;
The 3rd step deposit first polysilicon layer 4 and second polysilicon layer 4 '
Adopt low-pressure chemical vapor phase deposition, be first silica membrane 2 and second silica membrane 2 ' surface difference deposit first polysilicon layer 4 and second polysilicon layer 4 ' of LPCVD method at first silicon chip 0, thickness is 800nm ± 20nm, test diffusion sheet resistance Rs is 45~50 Ω/, and first polysilicon layer 4 and second polysilicon layer 4 ' are the arsenic-doped polysilicon layers;
The 4th step etching off second polysilicon layer 4 '
On first polysilicon layer 3, be coated with the first positive glue 5, adopt wet method etching off second polysilicon layer 4 ';
The 5th step was removed the first positive glue 5
Adopt acetone, under 40 degrees celsius, remove the first positive glue 5;
The 6th step deposit first silicon nitride film 6 and second silicon nitride film 6 '
Adopting low-pressure chemical vapor phase deposition technology, is first silicon nitride film 6 and second silicon nitride film 6 ' of 153nm ± 5nm at the two-sided deposition thickness of first silicon chip 0;
The 7th step deposit the 3rd polysilicon layer 7 and the 4th polysilicon layer 7 '
Adopt low-pressure chemical vapor phase deposition technology, two-sided deposition thickness at first silicon chip 0 is the 3rd polysilicon layer 7 and the 4th polysilicon layer 7 ' of 415nm ± 5nm, and first polysilicon layer 4, first silicon nitride film 6 and the 3rd polysilicon layer 7 that have prepared are together as complex optical film;
The 8th step etching off the 4th polysilicon layer 7 '
Be coated with the second positive glue 5 ' in first silicon chip, 0 front, acetone is adopted in etching off the 4th polysilicon layer 7 ' back, removes the second positive glue 5 ' under 40 degrees celsius;
The 9th step preparation fiber orientation groove corrosion mouth 8 and the first electrode corrosion mouth 9, the second electrode corrosion mouth 9 '
Be coated with the 3rd positive glue 5 at the back side of first silicon chip 0 "; adopt M5 fiber orientation groove and electrode mask exposure back to develop; at the 3rd positive glue 5 " go up the pattern of formation fiber orientation groove corrosion 8 and the first electrode corrosion mouth 9, the second electrode corrosion mouth 9 ', adopt the KOH reactive ion etching then, be that the RIE method erodes second silicon nitride film 6 ' in fiber orientation groove corrosion mouth 8 and the first electrode corrosion mouth 9, the second electrode corrosion mouth 9 ', expose second silica membrane 2 ', last plasma is removed the 3rd positive glue 5 ";
The tenth step deposit silicon dioxide support arm 10
Strengthen chemical gaseous phase at first silicon chip, 0 front using plasma, promptly PECVD depositing technics growthing silica support arm 10, and thickness is 1050nm ± 50nm;
The 11 step preparation complex optical film F-P cavity 11 and electrode hole 12
Be coated with the 4th positive glue 5_ in the front of first silicon chip 0; adopt M1 cavity mask exposure back to develop; on the 4th positive glue 5_, form the pattern of complex optical film F-P cavity 11 and electrode hole 12; be not subjected to the silicon dioxide support arm 10 of the 4th positive glue 5_ protection then with the corrosive liquid corrosion; remove at last the 4th positive glue 5_, the prescription of corrosive liquid is the HF of concentration 48%: NH
4F: H
2O=3ml: 6g: 10ml, remove the 4th positive glue 5_ at last:
The high reflective film 13 of the 12 step sputter alloy aluminum
Do the bottom electrode of prepared equalizer chip at the high reflective film 13 of second silicon chip, 1 surface sputtering alloy aluminum;
The 13 step bonding
With first silicon chip, 0 positive and second silicon chip, 1 front bonding under environment purification, get cavity body;
The 14 step preparation fiber orientation groove 14
Utilize first silica membrane 2 in the corrosive liquid corrosion fiber orientation groove corrosion mouth 8 and the first electrode corrosion mouth 9, the second electrode corrosion mouth 9 ', the prescription of corrosive liquid is the HF of concentration 48%: NH
4F: H
2O=3ml: 6g: 10ml, expose first silicon chip 0, utilize the anisotropy of silicon then, adopt concentration 25%TMAOH solution under 85 degrees centigrade condition, to corrode first silicon chip 0, time is 13 hours, expose the complex optical film and first polysilicon layer 4, first polysilicon layer 4 is double does the prepared equalizer chip power utmost point, adopt the complex optical film on the mechanical means removal electrode hole 12 then, bottom electrode alloy aluminum film 13 can be drawn from the surface, get MEMS electrically controlled dynamic gain equalizer chip.
Whole prepared process is shown in Fig. 1~14.
The present invention has following outstanding effect:
1. employing complex optical film, for the adjustable range of wavelength 1510nm, 1530nm, 1550nm, 1570nm optical signal gain greater than 15dB.
2. employing bonding technology improves product reliability.
3. cost is low, is suitable for producing in batches.
4. small product size is little, and is compatible mutually with the manufacture craft of large scale integrated circuit.
Description of drawings
Fig. 1 (a) is the schematic diagram of preparation first silicon chip 0.
Fig. 1 (b) is the schematic diagram of preparation second silicon chip 1.
Fig. 2 (a) is at first silicon chip, 0 silicon dioxide thin film growth schematic diagram.
Fig. 2 (b) is at second silicon chip, 1 silicon dioxide thin film growth schematic diagram.
Fig. 3 is that first polysilicon layer 4 of arsenic and the schematic diagram of second polysilicon layer 4 ' are mixed in deposit.
Fig. 4 is the schematic diagram of corrosion second polysilicon layer 4 '.
Fig. 5 is the schematic diagram of the first positive glue 5.
Fig. 6 is the schematic diagram of deposit first silicon nitride film 6 and second silicon nitride film 6 '.
Fig. 7 is the schematic diagram of deposit the 3rd polysilicon layer 7 and the 4th polysilicon layer 7 '.
Fig. 8 (a) is the schematic diagram of etching off the 4th polysilicon layer 7 '.
Fig. 8 (b) is a schematic diagram of removing the second positive glue 5 '.
Fig. 9 (a) is coated with the 3rd positive glue 5 " schematic diagram.
Fig. 9 (b) is the schematic diagram of preparation fiber orientation groove corrosion mouth 8 and the first electrode corrosion mouth 9, the second electrode corrosion mouth 9 '.
Fig. 9 (c) removes the 3rd positive glue 5 " schematic diagram.
Figure 10 is the schematic diagram of deposit silicon dioxide support arm 10.
Figure 11 (a) is the schematic diagram that is coated with the 4th positive glue 5_.
Figure 11 (b) is the schematic diagram of preparation complex optical film F-P cavity 11 and electrode hole 12.
Figure 11 (c) is a schematic diagram of removing the 4th positive glue 5_.
Figure 12 is the high reflective film 13 of sputter alloy aluminum, the i.e. schematic diagram of bottom electrode.
Figure 13 is a bonding technology, gets the schematic diagram of cavity body.
Figure 14 is the schematic diagram of preparation fiber orientation groove 14.