Patterning of silicon nitride for CMOS gate spacer technology. II. Impact of subsilicon surface carbon implantation on epitaxial regrowth

Abstract

International audienc

Five-step plasma-enhanced atomic layer etching of silicon nitride with a stable etched amount per cycle

“…It has been reported that the Si-C bonds are generated on the SiN surface during conventional RIE, 82) as well as on the Si surface. [83][84][85] Thus, the MD simulation results are qualitatively consistent with the earlier RIE experimental results, indicating that residual C atoms are firmly bonded with surface atoms after the desorption step. Because the Si-C bond energy is similar to the Si-N bond energy and a single C atom typically has four bonds to be connected with surface atoms, removing residual C atoms by Ar + ion bombardment requires the incident ion energy to be high enough to sputter SiN.…”

Mechanism of SiN etching rate fluctuation in atomic layer etching

“…Another possible reason is that Si-C bonds are formed on the surface. [27][28][29] As the binding energy of Si-C in the C (1s) photoemission (283.0 eV) is close to the peak position of a strong C-C (284.8 eV) bond, it was difficult to deconvolute the effect of Si-C. As Si-C is generated in the interface between HFC polymer and underlying SiN, the signal of Si-C seems to be under the detectable-level since the upper HFC polymer suppressed the photoelectron from the interface. Further study will be performed related to the Si-C bond by using other techniques.…”

A method for high selective etch of Si3N4 and SiC with ion modification and chemical removal

“…In conventional reactive ion etch (RIE) process, to obtain the desired mask selectivity, profile and CDs, fluorocarbon (FC) or hydro fluorocarbon (HFC) films are generated at the surface of a material, which act as a passivation layer for etch protection. [1][2][3][4][5][6][7][8][9][10] On the etch of Si 3 N 4 , as an example, high selectivity over Si up to 20 can be achieved by a carbon rich passivation layer made on top of the Si substrate. 11) However, such a deposition of the FC and HFC films frequently causes the clogging and etch stop issue during the process when the CD size becomes small.…”