서지주요정보
Sub-um 접촉 구멍 형성을 위한 시간 변조 RIE 플라즈마 식각 = Time-modulated RIE plasma etching for the patterning of Sub-um contact holes
서명 / 저자 Sub-um 접촉 구멍 형성을 위한 시간 변조 RIE 플라즈마 식각 = Time-modulated RIE plasma etching for the patterning of Sub-um contact holes / 문홍배.
저자명 문홍배 ; Moon, Hong-Bae
발행사항 [대전 : 한국과학기술원, 1996].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8006783

소장위치/청구기호

학술문화관(문화관) 보존서고

MAME 96005

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

The feature size of semiconductor devices for VLSI integrated circuits is continuously shrunken in order to achieve higher processing capability on a chip. To cope with this trend, the dry etching technology as a means of transfering fine patterns is required to have the improved selectivity, etch rate, damage, and etc. At the same time the precise control of plasma is warranted for the sake of precisely controlling the plasma, the time modulation of plasma source is suggested by others, previously. This technology uses the controlled radicals and ions, and their energies by adopting the difference between the relaxation time of electrons and the life time of radicals, while maintaining the plasma density. In this article, under the time modulated RF power, the possiblity of the control of the radicals, ions, and their energies is studied with an RIE etch of model AME 8300. In the experiment the contact hole is patterned, the materials such as thermal oxide, BPSG, HTO, p-doped Poly-Si film are etched. Such etching characterstics as etch rate, selectivity, anisotropy, physical damage are compared and evaluated between the case of continuous RF power and that of using time modulated RF power for each film. In the range of 10Hz~100KHz pulse modulation frequency, etching characteristics is studied as a function of the composition of etchant gas, RF power, DC bias. For the case of time modulated RF power, the distribution of forwarded power, reflected power, and DC bias are presented. The DC bias is abruptly increased below the pulse frequency of 500Hz and slowly so above 500Hz. If discharging $O_2/CHF_3$ gas in the TM RF power, the dissociation of radicals and ions is different from the case of high density plasma encountered in ECR or inductively coupled plasma, but the long life time of radicals can be analyzed. So in the range of low pulse frequency (100~500Hz), the etch rates of oxide films, the selectivity $SiO_2$/Poly-Si are increased due to the long life time of radicals at the same DC bias as that of the case using continuous wave(CW) RF power. In the case of the etch using $CHF_3$ gas, the etch of a forementioned films starts at the lower DC bias in the TM RF power than that in the CW RF power. And it is found that the extent of having polymer precursor active sites on the Poly-Si, the BPSG, the HTO, the thermal oxide films is decreasing in the order of the listed. The wafer surface temperature increases in proportion to the increase of the ion flux and ion energy. It is found that the surface temperature is lower in the case of TM RF power in comparison with the CW RF power, and is increased as the duty ratio increases. The TM RF power is applied to a contact hole pattern process used in an industry fab. The resulted etch profile and the size of the contact hole are not noticably different from those obtained using the CW power, but some minor change is noticed resulted from the different etched amounts for the various etch conditions. Also the contact string resistance is found to vary with the etch amounts. The physical damage done to P-type silicon wafer depends on the ion energy and ion flux during the plasma processing. The surface recombination is increased and the surface minority carrier decreased as physical damage is increased. So the lower DC bias in the TM mode gives lower damage. In conclusion, in comparison with the case of the CW RF power, the dissociations of radicals are not controlled in the time modulated RF power, but the etched amounts can be increased about 15% due to the long life time of radicals. The wafer surface temperature is maintained to the wanted level and the physical damage introduced to the wafer surface is decreased although adopting the same amount of DC bias.

서지기타정보

서지기타정보
청구기호 {MAME 96005
형태사항 x, 76 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Hong-Bae Moon
지도교수의 한글표기 : 전덕영
지도교수의 영문표기 : Duk-Young Jeon
학위논문 학위논문(석사) - 한국과학기술원 : 신소재공학과,
서지주기 참고문헌 : p. 75-76
주제 반응성 이온 식각
연속파
시간 변조
라디오파 전력
결함
RIE etching
Continuous wave
Time modulation
RF Power
Damage
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