1. Full name: Do Hong Minh                                          2. Sex: Male     

3. Date of birth: 16-8-1979                                             4. Place of birth: Bac Giang      

5. Admission decision number: 1118/QĐ-CTSV           Dated: 18-12-2012

6. Changes in academic process: Change the name of doctoral thesis    

(List the forms of change and corresponding times)

7. Official thesis title: A research on ferroelectric properties of micro/nano  BLT and PZT thin films prepared by solution process towards nonvolatile memories application

8. Major: Engineering physics                                           9. Code: 944012801QTD

10. Supervisors:       Ph.D. Bui Nguyen Quoc Trinh.

Assoc.Prof., Ph.D. Pham Đuc Thang

11. Summary of the new findings of the thesis:

By using the solution-processed method, we fabricated (BLT, PZT) ferroelectric thin films, (LNO, Pt) electrode thin films and (ITO) channel thin film with a high quality films, without cracked, good repeat. We surveyed the quality of the layers depend on the way of system of the thickness, the annealing temperature  and annealing method. We also surveyed the dependence of ferroelectric property of PZT film of the electrode films.

We have designed, fabricated and investigated the operation of micrometer size ferroelectric memories on Si/SiO2, sc-STO, pc-STO and glass substrates. Characteristics of the memories (output characteristics, I-V characteristics, the transfer characteristics and the on/off current ratio…) were investigated. The results have shown that the ferroelectric on sc-STO(111) substrate had many advantages, such as the small memory window (about 2 V), the large ON/OFF current ratio (106),  the OFF current ratio less than 10-8 A, the high ON current saturation (~ 4,6 mA).

In this study, a new technique has been implemented to fabricate the sub-100 nm FGTs, whose channel length is defined to be 30, 50 and 100 nm, patterned basing on electron beam (EB) lithography, dry etching and ashing. We point out that the new technique is promising to go further in reduction of the FGT cell size, which should be reduced for high-density storage in integration circuits, even to several nanometers. With the new technique, the memory functionality of the fabricated sub-100nm FGTs are comparable with that of the sub-m sized FGT. In particular, the ON/OFF current ratio is about 104-105, the memory window is 2.0, 1.8 and 1.7 V, and the field-effect mobility is 0.12, 0.07 and 0.16 cm2V-1s-1 for the LDS of 100, 50, and 30 nm, respectively.

12. Practical applicability, if any: Continue researching   

13. Further research directions, if any: Researching and developing nanometer-ordered memories in realization of practical applicability.

14. Thesis-related publications:

D. H. Minh, N. V. Loi, N. H. Duc, B. N. Q. Trinh, (2016) “Low-temperature PZT thin-film ferroelectric memories fabricated on SiO2/Si and glass substrates”, Journal of Science: Advanced Materials and Devices 1, pp. 75-79.

T. V. Dung, H. Ha, H. T. T. Tam, V. T. Dung, N. V. Dung, D. H. Minh, V. T. H. Trang, N. Q. Hoa, B. N. Q. Trinh, (2016) “Investigation of structural and ferroelectric properties of Bi3.25La0.75Ti3O12 thin film”, Journal of Science and Technology 54 (1A), pp. 80-87.

T. V. Dũng, V. T. H. Trang, V. T. Dung, N. V. Dũng, N. T. Bình, N. T. T. Thủy, N. Q. Hòa, Đ. H. Minh, B. N. Q. Trình,  (2015) “Khảo sát chế tạo màng mỏng nano LaNiO3 trên lá nhôm  thay thế đế Si trong tích hợp tụ điện sắt điện”, Tuyển tập Hội nghị Vật lí kỹ thuật và Ứng dụng toàn quốc lần thứ IV, tr. 289-295.

D. H. Minh, B. N. Q. Trinh, (2015) “Sub-100nm Ferroelectric-gate Thin-Film Transistor with Low-temperature PZT Fabricated on SiO2/Si Substrate”,  Ferroelectrics Letters, 42 (1), pp. 65–74

D. H. Minh, V. T. H. Trang, B. N. Q. Trinh, (2014) “Huge on-Current Ferroelectric-Gate Thin Film Transistor with Solution-Processed Indium Tin Oxide Channel”, Journal of Mathematics - Physics, 30 (1), pp. 16-23.

D. H. Minh, N. Q. Hoa, N. H. Tiep, N. N. Dinh and B. N. Q. Trinh, (2014), “Low-temperature PZT thin film ferroelectric memories fabricated on a glass substrate”, Proc. Of the meeting on Ferroelectric Materials and theirs Application (FMA31), Kyoto, Japan, pp. 75-76

B. N. Q. Trinh, D. H. Minh, and T. Shimoda, (2013) “Thin-film Transistor Fabricated by a Precise Alignment Nano-imprinting Lithography and Physical Dry-etching Method”, Proc. of 4th International Workshop on Nanotechnology and Application (IWNA-2013), pp.743-745.