Tuukka Rask made 24 saves, and David Pastrnak and Patrice Bergeron each had three points for the Bruins, who reached the Cup Final for the 20th time and third in the past nine seasons (2011, 2013).
"I think the last few games we knew we could be a little bit better than we've been," Marchand said. "Being up 3-0, everyone in the room wanted to be at their best, and I think everyone brought their best tonight. Sometimes it bounces your way. Obviously, you look at [Bergeron's] history, the way he steps up in big games, and [Pastrnak] was great tonight."
[WATCH: Bruins vs. Hurricanes Game 4 highlights | Complete series coverage]
Boston, which has won seven straight games since trailing the Columbus Blue Jackets 2-1 in the second round, will play the winner of the Western Conference Final. The San Jose Sharks lead that best-of-7 series against the St. Louis Blues 2-1.
"I think we've played as a team the whole year, and I think we've shown that," Bergeron said. "Our depth has been winning games for us, and that was the perfect example in this series. Everyone chipping in on any given night, and it was a big difference, I thought."
Video: BOS@CAR, Gm4: Marchand, Pastrnak combine for PPG
Curtis McElhinney made 19 saves for the Hurricanes, who defeated the Washington Capitals in seven games in the first round before sweeping the New York Islanders in the second round.
"Did I think we'd be here? Maybe not, but we were going to see if we could get here," Carolina captain Justin Williams said. "We're good enough to be in the final four, and that means we're good enough to do it again next year and get better and learn from this. Right now, it hurts, and it will for a little while."
Pastrnak gave the Bruins a 1-0 lead with a power-play goal at 4:46 of the second period. He beat defenseman Calvin de Haan to the net and tapped in a centering pass from Brad Marchand off the rush.
Bergeron finished a give-and-go with Pastrnak from the slot on the power play with 1:26 remaining in the second to make it 2-0. Bergeron has six power-play goals in the Stanley Cup Playoffs.
The Bruins went 7-for-15 on the power play in the series. The Hurricanes were 1-for-14.
"Everything's going OK, then we get into [special teams] where it's obviously a huge advantage for them, and they made us pay," Carolina coach Rod Brind'Amour said. "You've got to give them credit. There's just no weakness, no matter who they throw out there."
Video: BOS@CAR, Gm4: Bergeron finishes give-and-go for PPG
The Bruins capitalized on a Hurricanes turnover to make it 3-0. Jaccob Slavin's pass from behind the Carolina net deflected off Bergeron's skate to Pastrnak, who dished the puck back to Bergeron alone at the left post for his second goal of the night at 10:32 of the third period.
Marchand scored into an empty net with 2:17 left for the 4-0 final.
"Obviously still a long way [to go], a lot of work left in front of us, but I thought we've been focused, and that's what you need," Bergeron said. "Everyone is contributing, everyone is a leader in this locker room, and at this time of the year, that's what makes you advance."
Video: #ThirstForTheCup: Bruins heading to Stanley Cup Final
Bruins defenseman Zdeno Chara did not play because of an undisclosed injury, but he was in full uniform on the ice for the presentation of the Prince of Wales Trophy. He was replaced in the lineup by John Moore, who had one blocked shot in 11:48 in his fifth game of the postseason.
Boston defeated the Toronto Maple Leafs in seven games in the first round and the Columbus Blue Jackets in six games in the second round.
"Proud of the guys, especially the way we played today," coach Bruce Cassidy said. "We've earned the right be where we are, to go to the Stanley Cup Final. We beat three good teams, and there's some unfinished business, so that's part of the emotion that you keep in check. There's still four more steps to take."
Video: BOS@CAR, Gm4: Bergeron buries Pastrnak's crafty feed
They said it
"It means a lot. It's so difficult to advance in the playoffs, let alone make it to the Final. We need to really enjoy this but realize that we have lots of work to do. I mean, every year is a new year, different groups, you always think you have a chance, and I think the past few years we've really built something special here with a great group of guys. Really, just happy to be part of it." -- Bruins goalie Tuukka Rask
"It's always tough to swallow when the season ends abruptly like that. You've got to go home. I just told my kids I was planning on going to Boston tomorrow, but I'll be home tomorrow after school. Life goes on." -- Hurricanes captain Justin Williams
Need to know
The Bruins have made it to the Stanley Cup Final 10 times in the expansion era (since 1967-68), second to the Montreal Canadiens' 11. … It was the 15th time Boston swept a best-of-7 series. … The line of Marchand, Bergeron and Pastrnak has combined for 38.6 percent (22 of 57) of Boston's goals in the playoffs. … In 17 playoff games, Rask is 12-5 with a 1.84 goals-against average, a .942 save percentage and two shutouts. … Sebastian Aho led the Hurricanes with 12 points (five goals, seven assists) in the playoffs, and Teuvo Teravainen led them with seven goals.
Bruins: Host Game 1 of Stanley Cup Final (TBD)
Hurricanes: Season over
Video: Bruins complete sweep, advance to Stanley Cup Final