Flat line type ion trap mass analyzer based on MEMS (micro electro mechanical system) process and manufacturing method thereof

[0030] See figure 1 , 2 , A flat linear ion trap mass analyzer based on MEMS technology, including upper and lower substrates 12, and support beams supporting the upper and lower substrates 12. On the substrate 12, three pairs of upper and lower corresponding parallel to each other are sputtered in sequence The ion lens focusing electrodes 5, 4, 3, the front gate electrode 6, the main radio frequency electrode 10, the auxiliary radio frequency electrode 2, 9, the rear gate electrode 11, the ion outlet repelling electrodes 1, 7, pre-calibrated on the upper and lower substrates 12 A through hole is opened at the position as the ion outlet 13, and the bonding area 8 and 14 of the support beam and the borosilicate glass substrate; the support beam is made by cutting a silicon wafer 16 with a custom thickness to a predetermined size, or combining two pieces The silicon wafer 18 and the borosilicate glass 19 of conventional thickness are cut to a predetermined size and then electrostatically bonded twice; the regions between the upper and lower ion lens focusing electrodes 5, 4, and 3 corresponding to the upper and lower substrates 12 constitute ions. Focusing area 20, upper and lower front gate electrodes 6 corresponding to the upper and lower substrates 12, main radio frequency electrode 10, auxiliary radio frequency electrodes 2, 9, and the area between the rear gate electrode 11 constitute a linear ion trap quadrupole field area 21. The area between the corresponding upper and lower ion outlet repulsion electrodes 1 and 7 of the lower substrate 12 constitutes an ion export area 22. The ion outlets 13 are respectively located on different upper and lower sides of the main radio frequency electrodes on the upper and lower substrates 12, and are mutually staggered.

[0031] After the ion current 15 to be measured enters the ion focusing area 20, it is acted by the electrostatic field generated by the ion lens focusing electrodes 5, 4, 3, and the ion current converges in the middle to form a narrow ion beam, and the ion beam enters the linear ion trap quadrupole field Region 21, under the action of the linear ion trap potential field, the ions each oscillate in the linear ion trap potential field region 21. As the RF signal of the main RF electrode 10 changes, the linear ion trap potential field screens the ions. The target ion 17 with the corresponding mass-to-charge ratio is captured, and then the corresponding auxiliary AC signal is applied to the auxiliary RF electrodes 2, 9 to make the corresponding target ion 17 move between the auxiliary RF electrodes 2, 9 to resonance, and finally The target ions 17 get rid of the constraint of the linear ion trap potential field and enter the ion export area 22. The target ions are repelled by the electrostatic field generated by the ion exit repelling electrodes 1, 7 and fly out of the flat linear ion trap from the ion exit 13. The mass analyzer is finally detected by the external ion detector.

[0032] A method for manufacturing a flat linear ion trap mass analyzer based on MEMS technology specifically includes the following steps:

[0033] (1) Cut the upper and lower substrates according to the required size, and clean the surfaces of the upper and lower substrates;

[0034] (2) Spin-coating photoresist on the front surfaces of the upper and lower substrates, and sequentially perform photolithography and development;

[0035] (3) Sputtering metal films on the front surfaces of the upper and lower substrates after development;

[0036] (4) Form the front pattern after stripping to obtain the ion lens focusing electrode, front gate electrode, main radio frequency electrode, auxiliary radio frequency electrode, back door electrode, and ion outlet repulsion electrode;

[0037] (5) Punch holes in the marked positions on the substrate to form ion outlets;

[0038] (6) Cut the required thickness of the silicon wafer according to the required size into long strips to obtain the support beam;

[0039] (7) Glue the two support beams to the upper and lower substrates.

[0040] The support beam can be obtained by cutting silicon wafers of custom thickness into strips, or by cutting silicon wafers of conventional thickness and borosilicate glass of required thickness to the required size, and then combining the borosilicate glass strip with two pieces of conventional thickness The silicon strip is obtained after double-sided electrostatic bonding.