Development of Anisotropic Dry Etching Process Using Laser Cooling Method

A new method of anisotoropic dry etching using A laser-collimated neutral F radical beam has beenproposed. Using this方法，no damage nor pattern distortion by the charged particles is expected in the miniaturized Sidevices.(1) For generation of F radicals，we made 13.56 MHz plasma source to decompose NF - D23 - D2 gas. NF - D23 - D2 is the best matching forthe present purpose judged from the view points of radical generation efficiency, easy handling(2) The wavelength for The封闭laser cooling cycle was determinedto be 685.793nm by the precision emission spectrum analysis of NF D23 - D2 plasma.(3) the lowerstate of laser cooling cycle (3p - D14 - D1D - D30(/)7/2 - D3【tautomer】3s - D14 - D1P - d25 /2 - D2) is themetastable state. Therefore，the metastable lifetime τ D2F died2 of 3s die14 died1p died25 / died2 state is the key factor to accomplish成功的laser collimation of F radical beam使用spontaneous light force. So far, however，no reliable report on τ D2F D2 has been published. We have made a new approach to measureτ D2F died2 of 3s die14 D1P died25 / died2 state to get τ D2F died2 =3.7±0.5μs.(4) Based on the shortlifetime of 3s - D14 - D1P - d25 - 2 - D2 state，这不是一个实用的方式与伙伴F radical beam使用spontaneous light force. However，powerful laser collimation method using stimulated light force可以使用collimate Fradical beam.(5)我们已经开发了一个高度有效的ECR （electron cyclotron resonance）微波F radical beam. Compared to the RF radical source20-fold increase of the Si etching rate和80-fold increase of the 685.793nm emission intensity ofF radicals have been achieved by the developed ECR source.我们measured the Si etching rates with with而without the ion retarding bias voltage applied to the Si wafer.它包含了一个practical etching rate by neutral F radicals would be obtainable for semiconductor manufacturingprocess。

A new method of anisotoropic dry etching using a laser-collimated neutral F radical beam has been proposed. Using this method, no damage nor pattern distortion by the charged particles is expected in the miniaturized Si devices.(1) For generation of F radicals, we made 13.56 MHz plasma source to decompose NFィイD23ィエD2 gas. NFィイD23ィエD2 is the best matching for the present purpose judged from the view points of radical generation efficiency, easy handling, and no decomposition products.(2) The wavelength for the closed laser cooling cycle was determined to be 685.793nm by the precision emission spectrum analysis of NFィイD23ィエD2 plasma.(3) The lower state of laser cooling cycle (3pィイD14ィエD1DィイD30(/)7/2ィエD3【tautomer】3sィイD14ィエD1PィイD25/2ィエD2) is the metastable state. Therefore, the metastable lifetime τィイD2FィエD2 of 3sィイD14ィエD1PィイD25/2ィエD2 state is the key factor to accomplish successful laser collimation of F radical beam using spontaneous light force. So far, however, no reliable report on τィイD2FィエD2 has been published. We have made a new approach to measure τィイD2FィエD2 of 3sィイD14ィエD1PィイD25/2ィエD2 state to get τィイD2FィエD2=3.7±0.5μs.(4) Based on the short lifetime of 3sィイD14ィエD1PィイD25/2ィエD2 state, it is not a practical way to collimate F radical beam using spontaneous light force. However, the powerful laser collimation method using stimulated light force can be used to collimate F radical beam.(5) We have developed a highly efficient ECR (electron cyclotron resonance) microwave plasma source of F radical beam. Compared to the RF radical source, 20-fold increase of the Si etching rate and 80-fold increase of the 685.793nm emission intensity of F radicals have been achieved by the developed ECR source.(6) We measured the Si etching rates with and without the ion retarding bias voltage applied to the Si wafer. It was concluded that a practical etching rate by neutral F radicals would be obtainable for semiconductor manufacturing process.