I think this may be what you want. I can see 100KHZ on each pin, but don't have a scope and can't see the phasing. If I slow the frequency down I can see the 75% duty cycle.
//Square wave generator 100KHz
//two outputs 75% DutyCycle offset 270 degree
//Timer 1 PWM with ICR1 TOP end Mode 10
void setup() {
pinMode(9, OUTPUT); //output A
pinMode(10, OUTPUT); //output B
TCCR1A = 0; //clear timer registers
TCCR1B = 0;
TCNT1 = 0;
GTCCR |= 1 << PSRASY; //reset prescaler
//ICR1 and Prescaler sets frequency
//no prescaler .0625 us per count @ 16Mh
//160 counts x .0625 = 10 us = 100Khz
TCCR1B |= _BV(CS10); //no prescaler
ICR1 = 80;//PWM mode counts up and back down for 160 counts
OCR1A = 20; //Pin 9 match
//output A set rising/clear falling
//Rise at TCNT 20 upslope, High 120 counts, Fall at TCNT 20 downslope
//75% Duty Cycle Pulse centered on TCNT 80. High 120 Low 40
TCCR1A |= _BV(COM1A1) | _BV(COM1A0); //output A set rising/clear falling
OCR1B = 60; //Pin 10 match
//output B clear rising/set falling
//Fall at TCNT 60 upslope, Low 40, Rise at TCNT 60 downslope
//75% Duty Cycle Pulse centered on TCNT 0. High 120 Low 40
TCCR1A |= _BV(COM1B1); //output B clear rising/set falling
TCCR1B |= _BV(WGM13); //PWM mode with ICR1 Mode 10
TCCR1A |= _BV(WGM11); //WGM13:WGM10 set 1010
}
void loop () {}