US 9,829,796 B2  222  221  acceptibility is reduced or lost, or which is changed from  being proton-accepting to be acidic, by being decomposed  due to irradiation with active light or radiation, as a basic  compound.  Regarding the compound (PA) which has a proton-ac- cepting functional group and generates a compound in  which the proton-acceptibility is reduced or lost, or which is  changed from being proton-accepting to be acidic, by being  decomposed due to irradiation with active light or radiation,  the description in paragraphs "0379" to "0425" of JP2012- 32762A (which corresponds to paragraphs "0386" to "0435"  of US2012/0003590A) can be referred to, and the contents  thereof are incorporated in the present specification.  ( 6) Guanidine Compound  The composition of the present invention may further  contain a guanidine compound having a structure repre› sented by the following formula.  preferably within a range of 3 to 8, and particularly prefer› ably within a range of 4 to 8.  In addition, the guanidine compound (A) in the present  invention preferably does not have a nitrogen atom other  than a guanidine structure.  Specific examples of the guanidine compound are shown  below, but, the present invention is not limited thereto.  The guanidine compound exhibits strong basicity since  the positive charge of the conjugate acid is dispersed and  stabilized by the three nitrogen atoms.  For the basicity of the guanidine compound (A) of the  present invention, the pKa of a conjugate acid is preferably  6.0 or greater, preferably 7.0 to 20.0 since neutralization  reactivity with an acid is high and the roughness properties  are excellent, and more preferably 8.0 to 16.0.  Due to such strong basicity, the diffusibility of an acid is  suppressed, and the strong basicity can contribute to forma› tion of an excellent pattern shape.  The "pKa" here represents pKa in an aqueous solution,  and for example, it is described in Chemical Handbook (II)  (revised 4th edition, 1993, edited by The Chemical Society  of Japan, published by Maruzen Co., Ltd.), and a smaller  value means higher acidity. Specifically, the pKa in aqueous  solution can be obtained by measuring the acid dissociation  constant at 25°  C. using an infinite dilution aqueous solution,  and a value based on the database of Hammett substituent  constants and known literature values can also be deter› mined by calculation using the following software package  1. All of pKa values described in the present specification  are values determined by calculation using this software  package.  Software package 1: Advanced Chemistry Development  (ACD/Labs) Software V8.14 for Solaris (1994-2007 ACD/  Labs).  In the present invention, log Pis a logarithmic value of an  n-octanol/water distribution coefficient (P), and with respect  to a wide range of compounds, it is an effective parameter  that can characterize the hydrophilicity/hydrophobicity. In  general, the distribution coefficient is determined not by  experiment but by calculation, and in the present invention,  the distribution coefficient is a value calculated by a CS  ChemDraw Ultra Ver. 8.0 software package (Crippen’s  fragmentation method).  In addition, the log P of the guanidine compound (A) is  preferably 10 or less. When the log Pis the above value or  less, the guanidine compound can be uniformly contained in  a resist film.  The log P of the guanidine compound (A) in the present  invention is preferably within a range of 2 to 10, more  Log P: 4.29  Log P: 3.32  Log P: 3.1  Q  ~N~N~  H  H  Log P: 5.24  9  QN,O  N)lN  ~  H  H  Log P: 4.89  Q  QN~ND  H  H 